commit d79e307190910dfcb2d4258ee40ac4ba1df3fccb Author: Michal Arbet Date: Wed Jan 22 21:12:19 2020 +0100 Add initial version 1.0.7 of graphlib js library diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..b3085b8 --- /dev/null +++ b/.gitignore @@ -0,0 +1,9 @@ +*.pyc +*.sw? +*.sqlite3 +.DS_STORE +*.egg-info +.venv +.tox +build +dist diff --git a/.gitreview b/.gitreview new file mode 100644 index 0000000..7a292a9 --- /dev/null +++ b/.gitreview @@ -0,0 +1,4 @@ +[gerrit] +host=review.opendev.org +port=29418 +project=openstack/xstatic-graphlib.git diff --git a/MANIFEST.in b/MANIFEST.in new file mode 100644 index 0000000..af3cdd3 --- /dev/null +++ b/MANIFEST.in @@ -0,0 +1,6 @@ +include README.txt +recursive-include xstatic * +global-exclude *.pyc +global-exclude *.pyo +global-exclude *.orig +global-exclude *.rej diff --git a/README.txt b/README.txt new file mode 100644 index 0000000..ca7ccbf --- /dev/null +++ b/README.txt @@ -0,0 +1,13 @@ +XStatic-Graphlib +-------------- + +Graphlib JavaScript library packaged for setuptools (easy_install) / pip. + +This package is intended to be used by **any** project that needs these files. + +It intentionally does **not** provide any extra code except some metadata +**nor** has any extra requirements. You MAY use some minimal support code from +the XStatic base package, if you like. + +You can find more info about the xstatic packaging way in the package `XStatic`. + diff --git a/setup.cfg b/setup.cfg new file mode 100644 index 0000000..53dc8a2 --- /dev/null +++ b/setup.cfg @@ -0,0 +1,20 @@ +[metadata] +name = XStatic-Graphlib +description = Graphlib 1.0.7 (XStatic packaging standard) +description-file = README.rst +maintainer = Michal Arbet +maintainer-email = michal.arbet@ultimum.io +home-page = https://github.com/dagrejs/graphlib +keywords = graphlib xstatic +license = (same as Graphlib) +zip_safe = False +namespace_packages = + xstatic + xstatic.pkg + +[files] +packages = + xstatic + +[bdist_wheel] +universal = True diff --git a/setup.py b/setup.py new file mode 100644 index 0000000..1ca7f92 --- /dev/null +++ b/setup.py @@ -0,0 +1,26 @@ +from setuptools import setup, find_packages +from xstatic.pkg import graphlib as xs + +# The README.txt file should be written in reST so that PyPI can use +# it to generate your project's PyPI page. +long_description = open('README.txt').read() + +setup( + name=xs.PACKAGE_NAME, + version=xs.PACKAGE_VERSION, + description=xs.DESCRIPTION, + long_description=long_description, + long_description_content_type="text/markdown", + classifiers=xs.CLASSIFIERS, + keywords=xs.KEYWORDS, + maintainer=xs.MAINTAINER, + maintainer_email=xs.MAINTAINER_EMAIL, + license=xs.LICENSE, + url=xs.HOMEPAGE, + platforms=xs.PLATFORMS, + packages=find_packages(), + namespace_packages=['xstatic', 'xstatic.pkg'], + include_package_data=True, + zip_safe=False, + install_requires=[], +) diff --git a/tox.ini b/tox.ini new file mode 100644 index 0000000..6a1b29f --- /dev/null +++ b/tox.ini @@ -0,0 +1,8 @@ +[tox] +minversion = 1.6 +skipsdist = True +envlist = py27,py34 + +[testenv:venv] +basepython = python3 +commands = {posargs} diff --git a/xstatic/__init__.py b/xstatic/__init__.py new file mode 100644 index 0000000..de40ea7 --- /dev/null +++ b/xstatic/__init__.py @@ -0,0 +1 @@ +__import__('pkg_resources').declare_namespace(__name__) diff --git a/xstatic/pkg/__init__.py b/xstatic/pkg/__init__.py new file mode 100644 index 0000000..de40ea7 --- /dev/null +++ b/xstatic/pkg/__init__.py @@ -0,0 +1 @@ +__import__('pkg_resources').declare_namespace(__name__) diff --git a/xstatic/pkg/graphlib/__init__.py b/xstatic/pkg/graphlib/__init__.py new file mode 100644 index 0000000..c164966 --- /dev/null +++ b/xstatic/pkg/graphlib/__init__.py @@ -0,0 +1,49 @@ +""" +XStatic resource package + +See package 'XStatic' for documentation and basic tools. +""" + +DISPLAY_NAME = 'Graphlib' # official name, upper/lowercase allowed, no spaces +PACKAGE_NAME = 'XStatic-%s' % DISPLAY_NAME # name used for PyPi + +NAME = __name__.split('.')[-1] # package name (e.g. 'foo' or 'foo_bar') + # please use a all-lowercase valid python + # package name + +VERSION = '1.0.7' # version of the packaged files, please use the upstream + # version number +BUILD = '0' # our package build number, so we can release new builds + # with fixes for xstatic stuff. +PACKAGE_VERSION = VERSION + '.' + BUILD # version used for PyPi + +DESCRIPTION = "%s %s (XStatic packaging standard)" % (DISPLAY_NAME, VERSION) + +PLATFORMS = 'any' +CLASSIFIERS = [] +KEYWORDS = '%s xstatic' % NAME + +# XStatic-* package maintainer: +MAINTAINER = 'Michal Arbet' +MAINTAINER_EMAIL = 'michal.arbet@ultimum.io' + +# this refers to the project homepage of the stuff we packaged: +HOMEPAGE = 'https://github.com/dagrejs/graphlib' + +# this refers to all files: +LICENSE = '(same as %s)' % DISPLAY_NAME + +from os.path import join, dirname +BASE_DIR = join(dirname(__file__), 'data') +# linux package maintainers just can point to their file locations like this: +#BASE_DIR = '/usr/share/javascript/graphlib' + +LOCATIONS = { + # CDN locations (if no public CDN exists, use an empty dict) + # if value is a string, it is a base location, just append relative + # path/filename. if value is a dict, do another lookup using the + # relative path/filename you want. + # your relative path/filenames should usually be without version + # information, because either the base dir/url is exactly for this + # version or the mapping will care for accessing this version. +} diff --git a/xstatic/pkg/graphlib/data/graphlib.core.js b/xstatic/pkg/graphlib/data/graphlib.core.js new file mode 100644 index 0000000..9ccbe3f --- /dev/null +++ b/xstatic/pkg/graphlib/data/graphlib.core.js @@ -0,0 +1,1237 @@ +(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o 0) { + v = pq.removeMin(); + vEntry = results[v]; + if (vEntry.distance === Number.POSITIVE_INFINITY) { + break; + } + + edgeFn(v).forEach(updateNeighbors); + } + + return results; +} + +},{"../data/priority-queue":16,"../lodash":20}],7:[function(require,module,exports){ +var _ = require("../lodash"), + tarjan = require("./tarjan"); + +module.exports = findCycles; + +function findCycles(g) { + return _.filter(tarjan(g), function(cmpt) { + return cmpt.length > 1 || (cmpt.length === 1 && g.hasEdge(cmpt[0], cmpt[0])); + }); +} + +},{"../lodash":20,"./tarjan":14}],8:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = floydWarshall; + +var DEFAULT_WEIGHT_FUNC = _.constant(1); + +function floydWarshall(g, weightFn, edgeFn) { + return runFloydWarshall(g, + weightFn || DEFAULT_WEIGHT_FUNC, + edgeFn || function(v) { return g.outEdges(v); }); +} + +function runFloydWarshall(g, weightFn, edgeFn) { + var results = {}, + nodes = g.nodes(); + + nodes.forEach(function(v) { + results[v] = {}; + results[v][v] = { distance: 0 }; + nodes.forEach(function(w) { + if (v !== w) { + results[v][w] = { distance: Number.POSITIVE_INFINITY }; + } + }); + edgeFn(v).forEach(function(edge) { + var w = edge.v === v ? edge.w : edge.v, + d = weightFn(edge); + results[v][w] = { distance: d, predecessor: v }; + }); + }); + + nodes.forEach(function(k) { + var rowK = results[k]; + nodes.forEach(function(i) { + var rowI = results[i]; + nodes.forEach(function(j) { + var ik = rowI[k]; + var kj = rowK[j]; + var ij = rowI[j]; + var altDistance = ik.distance + kj.distance; + if (altDistance < ij.distance) { + ij.distance = altDistance; + ij.predecessor = kj.predecessor; + } + }); + }); + }); + + return results; +} + +},{"../lodash":20}],9:[function(require,module,exports){ +module.exports = { + components: require("./components"), + dijkstra: require("./dijkstra"), + dijkstraAll: require("./dijkstra-all"), + findCycles: require("./find-cycles"), + floydWarshall: require("./floyd-warshall"), + isAcyclic: require("./is-acyclic"), + postorder: require("./postorder"), + preorder: require("./preorder"), + prim: require("./prim"), + tarjan: require("./tarjan"), + topsort: require("./topsort") +}; + +},{"./components":3,"./dijkstra":6,"./dijkstra-all":5,"./find-cycles":7,"./floyd-warshall":8,"./is-acyclic":10,"./postorder":11,"./preorder":12,"./prim":13,"./tarjan":14,"./topsort":15}],10:[function(require,module,exports){ +var topsort = require("./topsort"); + +module.exports = isAcyclic; + +function isAcyclic(g) { + try { + topsort(g); + } catch (e) { + if (e instanceof topsort.CycleException) { + return false; + } + throw e; + } + return true; +} + +},{"./topsort":15}],11:[function(require,module,exports){ +var dfs = require("./dfs"); + +module.exports = postorder; + +function postorder(g, vs) { + return dfs(g, vs, "post"); +} + +},{"./dfs":4}],12:[function(require,module,exports){ +var dfs = require("./dfs"); + +module.exports = preorder; + +function preorder(g, vs) { + return dfs(g, vs, "pre"); +} + +},{"./dfs":4}],13:[function(require,module,exports){ +var _ = require("../lodash"), + Graph = require("../graph"), + PriorityQueue = require("../data/priority-queue"); + +module.exports = prim; + +function prim(g, weightFunc) { + var result = new Graph(), + parents = {}, + pq = new PriorityQueue(), + v; + + function updateNeighbors(edge) { + var w = edge.v === v ? edge.w : edge.v, + pri = pq.priority(w); + if (pri !== undefined) { + var edgeWeight = weightFunc(edge); + if (edgeWeight < pri) { + parents[w] = v; + pq.decrease(w, edgeWeight); + } + } + } + + if (g.nodeCount() === 0) { + return result; + } + + _.each(g.nodes(), function(v) { + pq.add(v, Number.POSITIVE_INFINITY); + result.setNode(v); + }); + + // Start from an arbitrary node + pq.decrease(g.nodes()[0], 0); + + var init = false; + while (pq.size() > 0) { + v = pq.removeMin(); + if (_.has(parents, v)) { + result.setEdge(v, parents[v]); + } else if (init) { + throw new Error("Input graph is not connected: " + g); + } else { + init = true; + } + + g.nodeEdges(v).forEach(updateNeighbors); + } + + return result; +} + +},{"../data/priority-queue":16,"../graph":17,"../lodash":20}],14:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = tarjan; + +function tarjan(g) { + var index = 0, + stack = [], + visited = {}, // node id -> { onStack, lowlink, index } + results = []; + + function dfs(v) { + var entry = visited[v] = { + onStack: true, + lowlink: index, + index: index++ + }; + stack.push(v); + + g.successors(v).forEach(function(w) { + if (!_.has(visited, w)) { + dfs(w); + entry.lowlink = Math.min(entry.lowlink, visited[w].lowlink); + } else if (visited[w].onStack) { + entry.lowlink = Math.min(entry.lowlink, visited[w].index); + } + }); + + if (entry.lowlink === entry.index) { + var cmpt = [], + w; + do { + w = stack.pop(); + visited[w].onStack = false; + cmpt.push(w); + } while (v !== w); + results.push(cmpt); + } + } + + g.nodes().forEach(function(v) { + if (!_.has(visited, v)) { + dfs(v); + } + }); + + return results; +} + +},{"../lodash":20}],15:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = topsort; +topsort.CycleException = CycleException; + +function topsort(g) { + var visited = {}, + stack = {}, + results = []; + + function visit(node) { + if (_.has(stack, node)) { + throw new CycleException(); + } + + if (!_.has(visited, node)) { + stack[node] = true; + visited[node] = true; + _.each(g.predecessors(node), visit); + delete stack[node]; + results.push(node); + } + } + + _.each(g.sinks(), visit); + + if (_.size(visited) !== g.nodeCount()) { + throw new CycleException(); + } + + return results; +} + +function CycleException() {} + +},{"../lodash":20}],16:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = PriorityQueue; + +/** + * A min-priority queue data structure. This algorithm is derived from Cormen, + * et al., "Introduction to Algorithms". The basic idea of a min-priority + * queue is that you can efficiently (in O(1) time) get the smallest key in + * the queue. Adding and removing elements takes O(log n) time. A key can + * have its priority decreased in O(log n) time. + */ +function PriorityQueue() { + this._arr = []; + this._keyIndices = {}; +} + +/** + * Returns the number of elements in the queue. Takes `O(1)` time. + */ +PriorityQueue.prototype.size = function() { + return this._arr.length; +}; + +/** + * Returns the keys that are in the queue. Takes `O(n)` time. + */ +PriorityQueue.prototype.keys = function() { + return this._arr.map(function(x) { return x.key; }); +}; + +/** + * Returns `true` if **key** is in the queue and `false` if not. + */ +PriorityQueue.prototype.has = function(key) { + return _.has(this._keyIndices, key); +}; + +/** + * Returns the priority for **key**. If **key** is not present in the queue + * then this function returns `undefined`. Takes `O(1)` time. + * + * @param {Object} key + */ +PriorityQueue.prototype.priority = function(key) { + var index = this._keyIndices[key]; + if (index !== undefined) { + return this._arr[index].priority; + } +}; + +/** + * Returns the key for the minimum element in this queue. If the queue is + * empty this function throws an Error. Takes `O(1)` time. + */ +PriorityQueue.prototype.min = function() { + if (this.size() === 0) { + throw new Error("Queue underflow"); + } + return this._arr[0].key; +}; + +/** + * Inserts a new key into the priority queue. If the key already exists in + * the queue this function returns `false`; otherwise it will return `true`. + * Takes `O(n)` time. + * + * @param {Object} key the key to add + * @param {Number} priority the initial priority for the key + */ +PriorityQueue.prototype.add = function(key, priority) { + var keyIndices = this._keyIndices; + key = String(key); + if (!_.has(keyIndices, key)) { + var arr = this._arr; + var index = arr.length; + keyIndices[key] = index; + arr.push({key: key, priority: priority}); + this._decrease(index); + return true; + } + return false; +}; + +/** + * Removes and returns the smallest key in the queue. Takes `O(log n)` time. + */ +PriorityQueue.prototype.removeMin = function() { + this._swap(0, this._arr.length - 1); + var min = this._arr.pop(); + delete this._keyIndices[min.key]; + this._heapify(0); + return min.key; +}; + +/** + * Decreases the priority for **key** to **priority**. If the new priority is + * greater than the previous priority, this function will throw an Error. + * + * @param {Object} key the key for which to raise priority + * @param {Number} priority the new priority for the key + */ +PriorityQueue.prototype.decrease = function(key, priority) { + var index = this._keyIndices[key]; + if (priority > this._arr[index].priority) { + throw new Error("New priority is greater than current priority. " + + "Key: " + key + " Old: " + this._arr[index].priority + " New: " + priority); + } + this._arr[index].priority = priority; + this._decrease(index); +}; + +PriorityQueue.prototype._heapify = function(i) { + var arr = this._arr; + var l = 2 * i, + r = l + 1, + largest = i; + if (l < arr.length) { + largest = arr[l].priority < arr[largest].priority ? l : largest; + if (r < arr.length) { + largest = arr[r].priority < arr[largest].priority ? r : largest; + } + if (largest !== i) { + this._swap(i, largest); + this._heapify(largest); + } + } +}; + +PriorityQueue.prototype._decrease = function(index) { + var arr = this._arr; + var priority = arr[index].priority; + var parent; + while (index !== 0) { + parent = index >> 1; + if (arr[parent].priority < priority) { + break; + } + this._swap(index, parent); + index = parent; + } +}; + +PriorityQueue.prototype._swap = function(i, j) { + var arr = this._arr; + var keyIndices = this._keyIndices; + var origArrI = arr[i]; + var origArrJ = arr[j]; + arr[i] = origArrJ; + arr[j] = origArrI; + keyIndices[origArrJ.key] = i; + keyIndices[origArrI.key] = j; +}; + +},{"../lodash":20}],17:[function(require,module,exports){ +"use strict"; + +var _ = require("./lodash"); + +module.exports = Graph; + +var DEFAULT_EDGE_NAME = "\x00", + GRAPH_NODE = "\x00", + EDGE_KEY_DELIM = "\x01"; + +// Implementation notes: +// +// * Node id query functions should return string ids for the nodes +// * Edge id query functions should return an "edgeObj", edge object, that is +// composed of enough information to uniquely identify an edge: {v, w, name}. +// * Internally we use an "edgeId", a stringified form of the edgeObj, to +// reference edges. This is because we need a performant way to look these +// edges up and, object properties, which have string keys, are the closest +// we're going to get to a performant hashtable in JavaScript. + +function Graph(opts) { + this._isDirected = _.has(opts, "directed") ? opts.directed : true; + this._isMultigraph = _.has(opts, "multigraph") ? opts.multigraph : false; + this._isCompound = _.has(opts, "compound") ? opts.compound : false; + + // Label for the graph itself + this._label = undefined; + + // Defaults to be set when creating a new node + this._defaultNodeLabelFn = _.constant(undefined); + + // Defaults to be set when creating a new edge + this._defaultEdgeLabelFn = _.constant(undefined); + + // v -> label + this._nodes = {}; + + if (this._isCompound) { + // v -> parent + this._parent = {}; + + // v -> children + this._children = {}; + this._children[GRAPH_NODE] = {}; + } + + // v -> edgeObj + this._in = {}; + + // u -> v -> Number + this._preds = {}; + + // v -> edgeObj + this._out = {}; + + // v -> w -> Number + this._sucs = {}; + + // e -> edgeObj + this._edgeObjs = {}; + + // e -> label + this._edgeLabels = {}; +} + +/* Number of nodes in the graph. Should only be changed by the implementation. */ +Graph.prototype._nodeCount = 0; + +/* Number of edges in the graph. Should only be changed by the implementation. */ +Graph.prototype._edgeCount = 0; + + +/* === Graph functions ========= */ + +Graph.prototype.isDirected = function() { + return this._isDirected; +}; + +Graph.prototype.isMultigraph = function() { + return this._isMultigraph; +}; + +Graph.prototype.isCompound = function() { + return this._isCompound; +}; + +Graph.prototype.setGraph = function(label) { + this._label = label; + return this; +}; + +Graph.prototype.graph = function() { + return this._label; +}; + + +/* === Node functions ========== */ + +Graph.prototype.setDefaultNodeLabel = function(newDefault) { + if (!_.isFunction(newDefault)) { + newDefault = _.constant(newDefault); + } + this._defaultNodeLabelFn = newDefault; + return this; +}; + +Graph.prototype.nodeCount = function() { + return this._nodeCount; +}; + +Graph.prototype.nodes = function() { + return _.keys(this._nodes); +}; + +Graph.prototype.sources = function() { + return _.filter(this.nodes(), function(v) { + return _.isEmpty(this._in[v]); + }, this); +}; + +Graph.prototype.sinks = function() { + return _.filter(this.nodes(), function(v) { + return _.isEmpty(this._out[v]); + }, this); +}; + +Graph.prototype.setNodes = function(vs, value) { + var args = arguments; + _.each(vs, function(v) { + if (args.length > 1) { + this.setNode(v, value); + } else { + this.setNode(v); + } + }, this); + return this; +}; + +Graph.prototype.setNode = function(v, value) { + if (_.has(this._nodes, v)) { + if (arguments.length > 1) { + this._nodes[v] = value; + } + return this; + } + + this._nodes[v] = arguments.length > 1 ? value : this._defaultNodeLabelFn(v); + if (this._isCompound) { + this._parent[v] = GRAPH_NODE; + this._children[v] = {}; + this._children[GRAPH_NODE][v] = true; + } + this._in[v] = {}; + this._preds[v] = {}; + this._out[v] = {}; + this._sucs[v] = {}; + ++this._nodeCount; + return this; +}; + +Graph.prototype.node = function(v) { + return this._nodes[v]; +}; + +Graph.prototype.hasNode = function(v) { + return _.has(this._nodes, v); +}; + +Graph.prototype.removeNode = function(v) { + var self = this; + if (_.has(this._nodes, v)) { + var removeEdge = function(e) { self.removeEdge(self._edgeObjs[e]); }; + delete this._nodes[v]; + if (this._isCompound) { + this._removeFromParentsChildList(v); + delete this._parent[v]; + _.each(this.children(v), function(child) { + this.setParent(child); + }, this); + delete this._children[v]; + } + _.each(_.keys(this._in[v]), removeEdge); + delete this._in[v]; + delete this._preds[v]; + _.each(_.keys(this._out[v]), removeEdge); + delete this._out[v]; + delete this._sucs[v]; + --this._nodeCount; + } + return this; +}; + +Graph.prototype.setParent = function(v, parent) { + if (!this._isCompound) { + throw new Error("Cannot set parent in a non-compound graph"); + } + + if (_.isUndefined(parent)) { + parent = GRAPH_NODE; + } else { + // Coerce parent to string + parent += ""; + for (var ancestor = parent; + !_.isUndefined(ancestor); + ancestor = this.parent(ancestor)) { + if (ancestor === v) { + throw new Error("Setting " + parent+ " as parent of " + v + + " would create create a cycle"); + } + } + + this.setNode(parent); + } + + this.setNode(v); + this._removeFromParentsChildList(v); + this._parent[v] = parent; + this._children[parent][v] = true; + return this; +}; + +Graph.prototype._removeFromParentsChildList = function(v) { + delete this._children[this._parent[v]][v]; +}; + +Graph.prototype.parent = function(v) { + if (this._isCompound) { + var parent = this._parent[v]; + if (parent !== GRAPH_NODE) { + return parent; + } + } +}; + +Graph.prototype.children = function(v) { + if (_.isUndefined(v)) { + v = GRAPH_NODE; + } + + if (this._isCompound) { + var children = this._children[v]; + if (children) { + return _.keys(children); + } + } else if (v === GRAPH_NODE) { + return this.nodes(); + } else if (this.hasNode(v)) { + return []; + } +}; + +Graph.prototype.predecessors = function(v) { + var predsV = this._preds[v]; + if (predsV) { + return _.keys(predsV); + } +}; + +Graph.prototype.successors = function(v) { + var sucsV = this._sucs[v]; + if (sucsV) { + return _.keys(sucsV); + } +}; + +Graph.prototype.neighbors = function(v) { + var preds = this.predecessors(v); + if (preds) { + return _.union(preds, this.successors(v)); + } +}; + +Graph.prototype.filterNodes = function(filter) { + var copy = new this.constructor({ + directed: this._isDirected, + multigraph: this._isMultigraph, + compound: this._isCompound + }); + + copy.setGraph(this.graph()); + + _.each(this._nodes, function(value, v) { + if (filter(v)) { + copy.setNode(v, value); + } + }, this); + + _.each(this._edgeObjs, function(e) { + if (copy.hasNode(e.v) && copy.hasNode(e.w)) { + copy.setEdge(e, this.edge(e)); + } + }, this); + + var self = this; + var parents = {}; + function findParent(v) { + var parent = self.parent(v); + if (parent === undefined || copy.hasNode(parent)) { + parents[v] = parent; + return parent; + } else if (parent in parents) { + return parents[parent]; + } else { + return findParent(parent); + } + } + + if (this._isCompound) { + _.each(copy.nodes(), function(v) { + copy.setParent(v, findParent(v)); + }); + } + + return copy; +}; + +/* === Edge functions ========== */ + +Graph.prototype.setDefaultEdgeLabel = function(newDefault) { + if (!_.isFunction(newDefault)) { + newDefault = _.constant(newDefault); + } + this._defaultEdgeLabelFn = newDefault; + return this; +}; + +Graph.prototype.edgeCount = function() { + return this._edgeCount; +}; + +Graph.prototype.edges = function() { + return _.values(this._edgeObjs); +}; + +Graph.prototype.setPath = function(vs, value) { + var self = this, + args = arguments; + _.reduce(vs, function(v, w) { + if (args.length > 1) { + self.setEdge(v, w, value); + } else { + self.setEdge(v, w); + } + return w; + }); + return this; +}; + +/* + * setEdge(v, w, [value, [name]]) + * setEdge({ v, w, [name] }, [value]) + */ +Graph.prototype.setEdge = function() { + var v, w, name, value, + valueSpecified = false, + arg0 = arguments[0]; + + if (typeof arg0 === "object" && arg0 !== null && "v" in arg0) { + v = arg0.v; + w = arg0.w; + name = arg0.name; + if (arguments.length === 2) { + value = arguments[1]; + valueSpecified = true; + } + } else { + v = arg0; + w = arguments[1]; + name = arguments[3]; + if (arguments.length > 2) { + value = arguments[2]; + valueSpecified = true; + } + } + + v = "" + v; + w = "" + w; + if (!_.isUndefined(name)) { + name = "" + name; + } + + var e = edgeArgsToId(this._isDirected, v, w, name); + if (_.has(this._edgeLabels, e)) { + if (valueSpecified) { + this._edgeLabels[e] = value; + } + return this; + } + + if (!_.isUndefined(name) && !this._isMultigraph) { + throw new Error("Cannot set a named edge when isMultigraph = false"); + } + + // It didn't exist, so we need to create it. + // First ensure the nodes exist. + this.setNode(v); + this.setNode(w); + + this._edgeLabels[e] = valueSpecified ? value : this._defaultEdgeLabelFn(v, w, name); + + var edgeObj = edgeArgsToObj(this._isDirected, v, w, name); + // Ensure we add undirected edges in a consistent way. + v = edgeObj.v; + w = edgeObj.w; + + Object.freeze(edgeObj); + this._edgeObjs[e] = edgeObj; + incrementOrInitEntry(this._preds[w], v); + incrementOrInitEntry(this._sucs[v], w); + this._in[w][e] = edgeObj; + this._out[v][e] = edgeObj; + this._edgeCount++; + return this; +}; + +Graph.prototype.edge = function(v, w, name) { + var e = (arguments.length === 1 + ? edgeObjToId(this._isDirected, arguments[0]) + : edgeArgsToId(this._isDirected, v, w, name)); + return this._edgeLabels[e]; +}; + +Graph.prototype.hasEdge = function(v, w, name) { + var e = (arguments.length === 1 + ? edgeObjToId(this._isDirected, arguments[0]) + : edgeArgsToId(this._isDirected, v, w, name)); + return _.has(this._edgeLabels, e); +}; + +Graph.prototype.removeEdge = function(v, w, name) { + var e = (arguments.length === 1 + ? edgeObjToId(this._isDirected, arguments[0]) + : edgeArgsToId(this._isDirected, v, w, name)), + edge = this._edgeObjs[e]; + if (edge) { + v = edge.v; + w = edge.w; + delete this._edgeLabels[e]; + delete this._edgeObjs[e]; + decrementOrRemoveEntry(this._preds[w], v); + decrementOrRemoveEntry(this._sucs[v], w); + delete this._in[w][e]; + delete this._out[v][e]; + this._edgeCount--; + } + return this; +}; + +Graph.prototype.inEdges = function(v, u) { + var inV = this._in[v]; + if (inV) { + var edges = _.values(inV); + if (!u) { + return edges; + } + return _.filter(edges, function(edge) { return edge.v === u; }); + } +}; + +Graph.prototype.outEdges = function(v, w) { + var outV = this._out[v]; + if (outV) { + var edges = _.values(outV); + if (!w) { + return edges; + } + return _.filter(edges, function(edge) { return edge.w === w; }); + } +}; + +Graph.prototype.nodeEdges = function(v, w) { + var inEdges = this.inEdges(v, w); + if (inEdges) { + return inEdges.concat(this.outEdges(v, w)); + } +}; + +function incrementOrInitEntry(map, k) { + if (map[k]) { + map[k]++; + } else { + map[k] = 1; + } +} + +function decrementOrRemoveEntry(map, k) { + if (!--map[k]) { delete map[k]; } +} + +function edgeArgsToId(isDirected, v_, w_, name) { + var v = "" + v_; + var w = "" + w_; + if (!isDirected && v > w) { + var tmp = v; + v = w; + w = tmp; + } + return v + EDGE_KEY_DELIM + w + EDGE_KEY_DELIM + + (_.isUndefined(name) ? DEFAULT_EDGE_NAME : name); +} + +function edgeArgsToObj(isDirected, v_, w_, name) { + var v = "" + v_; + var w = "" + w_; + if (!isDirected && v > w) { + var tmp = v; + v = w; + w = tmp; + } + var edgeObj = { v: v, w: w }; + if (name) { + edgeObj.name = name; + } + return edgeObj; +} + +function edgeObjToId(isDirected, edgeObj) { + return edgeArgsToId(isDirected, edgeObj.v, edgeObj.w, edgeObj.name); +} + +},{"./lodash":20}],18:[function(require,module,exports){ +// Includes only the "core" of graphlib +module.exports = { + Graph: require("./graph"), + version: require("./version") +}; + +},{"./graph":17,"./version":21}],19:[function(require,module,exports){ +var _ = require("./lodash"), + Graph = require("./graph"); + +module.exports = { + write: write, + read: read +}; + +function write(g) { + var json = { + options: { + directed: g.isDirected(), + multigraph: g.isMultigraph(), + compound: g.isCompound() + }, + nodes: writeNodes(g), + edges: writeEdges(g) + }; + if (!_.isUndefined(g.graph())) { + json.value = _.clone(g.graph()); + } + return json; +} + +function writeNodes(g) { + return _.map(g.nodes(), function(v) { + var nodeValue = g.node(v), + parent = g.parent(v), + node = { v: v }; + if (!_.isUndefined(nodeValue)) { + node.value = nodeValue; + } + if (!_.isUndefined(parent)) { + node.parent = parent; + } + return node; + }); +} + +function writeEdges(g) { + return _.map(g.edges(), function(e) { + var edgeValue = g.edge(e), + edge = { v: e.v, w: e.w }; + if (!_.isUndefined(e.name)) { + edge.name = e.name; + } + if (!_.isUndefined(edgeValue)) { + edge.value = edgeValue; + } + return edge; + }); +} + +function read(json) { + var g = new Graph(json.options).setGraph(json.value); + _.each(json.nodes, function(entry) { + g.setNode(entry.v, entry.value); + if (entry.parent) { + g.setParent(entry.v, entry.parent); + } + }); + _.each(json.edges, function(entry) { + g.setEdge({ v: entry.v, w: entry.w, name: entry.name }, entry.value); + }); + return g; +} + +},{"./graph":17,"./lodash":20}],20:[function(require,module,exports){ +/* global window */ + +var lodash; + +if (typeof require === "function") { + try { + lodash = require("lodash"); + } catch (e) {} +} + +if (!lodash) { + lodash = window._; +} + +module.exports = lodash; + +},{"lodash":undefined}],21:[function(require,module,exports){ +module.exports = '1.0.7'; + +},{}]},{},[1]); diff --git a/xstatic/pkg/graphlib/data/graphlib.core.min.js b/xstatic/pkg/graphlib/data/graphlib.core.min.js new file mode 100644 index 0000000..3638866 --- /dev/null +++ b/xstatic/pkg/graphlib/data/graphlib.core.min.js @@ -0,0 +1,31 @@ +(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o0){v=pq.removeMin();vEntry=results[v];if(vEntry.distance===Number.POSITIVE_INFINITY){break}edgeFn(v).forEach(updateNeighbors)}return results}},{"../data/priority-queue":16,"../lodash":20}],7:[function(require,module,exports){var _=require("../lodash"),tarjan=require("./tarjan");module.exports=findCycles;function findCycles(g){return _.filter(tarjan(g),function(cmpt){return cmpt.length>1||cmpt.length===1&&g.hasEdge(cmpt[0],cmpt[0])})}},{"../lodash":20,"./tarjan":14}],8:[function(require,module,exports){var _=require("../lodash");module.exports=floydWarshall;var DEFAULT_WEIGHT_FUNC=_.constant(1);function floydWarshall(g,weightFn,edgeFn){return runFloydWarshall(g,weightFn||DEFAULT_WEIGHT_FUNC,edgeFn||function(v){return g.outEdges(v)})}function runFloydWarshall(g,weightFn,edgeFn){var results={},nodes=g.nodes();nodes.forEach(function(v){results[v]={};results[v][v]={distance:0};nodes.forEach(function(w){if(v!==w){results[v][w]={distance:Number.POSITIVE_INFINITY}}});edgeFn(v).forEach(function(edge){var w=edge.v===v?edge.w:edge.v,d=weightFn(edge);results[v][w]={distance:d,predecessor:v}})});nodes.forEach(function(k){var rowK=results[k];nodes.forEach(function(i){var rowI=results[i];nodes.forEach(function(j){var ik=rowI[k];var kj=rowK[j];var ij=rowI[j];var altDistance=ik.distance+kj.distance;if(altDistance0){v=pq.removeMin();if(_.has(parents,v)){result.setEdge(v,parents[v])}else if(init){throw new Error("Input graph is not connected: "+g)}else{init=true}g.nodeEdges(v).forEach(updateNeighbors)}return result}},{"../data/priority-queue":16,"../graph":17,"../lodash":20}],14:[function(require,module,exports){var _=require("../lodash");module.exports=tarjan;function tarjan(g){var index=0,stack=[],visited={},results=[];function dfs(v){var entry=visited[v]={onStack:true,lowlink:index,index:index++};stack.push(v);g.successors(v).forEach(function(w){if(!_.has(visited,w)){dfs(w);entry.lowlink=Math.min(entry.lowlink,visited[w].lowlink)}else if(visited[w].onStack){entry.lowlink=Math.min(entry.lowlink,visited[w].index)}});if(entry.lowlink===entry.index){var cmpt=[],w;do{w=stack.pop();visited[w].onStack=false;cmpt.push(w)}while(v!==w);results.push(cmpt)}}g.nodes().forEach(function(v){if(!_.has(visited,v)){dfs(v)}});return results}},{"../lodash":20}],15:[function(require,module,exports){var _=require("../lodash");module.exports=topsort;topsort.CycleException=CycleException;function topsort(g){var visited={},stack={},results=[];function visit(node){if(_.has(stack,node)){throw new CycleException}if(!_.has(visited,node)){stack[node]=true;visited[node]=true;_.each(g.predecessors(node),visit);delete stack[node];results.push(node)}}_.each(g.sinks(),visit);if(_.size(visited)!==g.nodeCount()){throw new CycleException}return results}function CycleException(){}},{"../lodash":20}],16:[function(require,module,exports){var _=require("../lodash");module.exports=PriorityQueue;function PriorityQueue(){this._arr=[];this._keyIndices={}}PriorityQueue.prototype.size=function(){return this._arr.length};PriorityQueue.prototype.keys=function(){return this._arr.map(function(x){return x.key})};PriorityQueue.prototype.has=function(key){return _.has(this._keyIndices,key)};PriorityQueue.prototype.priority=function(key){var index=this._keyIndices[key];if(index!==undefined){return this._arr[index].priority}};PriorityQueue.prototype.min=function(){if(this.size()===0){throw new Error("Queue underflow")}return this._arr[0].key};PriorityQueue.prototype.add=function(key,priority){var keyIndices=this._keyIndices;key=String(key);if(!_.has(keyIndices,key)){var arr=this._arr;var index=arr.length;keyIndices[key]=index;arr.push({key:key,priority:priority});this._decrease(index);return true}return false};PriorityQueue.prototype.removeMin=function(){this._swap(0,this._arr.length-1);var min=this._arr.pop();delete this._keyIndices[min.key];this._heapify(0);return min.key};PriorityQueue.prototype.decrease=function(key,priority){var index=this._keyIndices[key];if(priority>this._arr[index].priority){throw new Error("New priority is greater than current priority. "+"Key: "+key+" Old: "+this._arr[index].priority+" New: "+priority)}this._arr[index].priority=priority;this._decrease(index)};PriorityQueue.prototype._heapify=function(i){var arr=this._arr;var l=2*i,r=l+1,largest=i;if(l>1;if(arr[parent].priority1){this.setNode(v,value)}else{this.setNode(v)}},this);return this};Graph.prototype.setNode=function(v,value){if(_.has(this._nodes,v)){if(arguments.length>1){this._nodes[v]=value}return this}this._nodes[v]=arguments.length>1?value:this._defaultNodeLabelFn(v);if(this._isCompound){this._parent[v]=GRAPH_NODE;this._children[v]={};this._children[GRAPH_NODE][v]=true}this._in[v]={};this._preds[v]={};this._out[v]={};this._sucs[v]={};++this._nodeCount;return this};Graph.prototype.node=function(v){return this._nodes[v]};Graph.prototype.hasNode=function(v){return _.has(this._nodes,v)};Graph.prototype.removeNode=function(v){var self=this;if(_.has(this._nodes,v)){var removeEdge=function(e){self.removeEdge(self._edgeObjs[e])};delete this._nodes[v];if(this._isCompound){this._removeFromParentsChildList(v);delete this._parent[v];_.each(this.children(v),function(child){this.setParent(child)},this);delete this._children[v]}_.each(_.keys(this._in[v]),removeEdge);delete this._in[v];delete this._preds[v];_.each(_.keys(this._out[v]),removeEdge);delete this._out[v];delete this._sucs[v];--this._nodeCount}return this};Graph.prototype.setParent=function(v,parent){if(!this._isCompound){throw new Error("Cannot set parent in a non-compound graph")}if(_.isUndefined(parent)){parent=GRAPH_NODE}else{parent+="";for(var ancestor=parent;!_.isUndefined(ancestor);ancestor=this.parent(ancestor)){if(ancestor===v){throw new Error("Setting "+parent+" as parent of "+v+" would create create a cycle")}}this.setNode(parent)}this.setNode(v);this._removeFromParentsChildList(v);this._parent[v]=parent;this._children[parent][v]=true;return this};Graph.prototype._removeFromParentsChildList=function(v){delete this._children[this._parent[v]][v]};Graph.prototype.parent=function(v){if(this._isCompound){var parent=this._parent[v];if(parent!==GRAPH_NODE){return parent}}};Graph.prototype.children=function(v){if(_.isUndefined(v)){v=GRAPH_NODE}if(this._isCompound){var children=this._children[v];if(children){return _.keys(children)}}else if(v===GRAPH_NODE){return this.nodes()}else if(this.hasNode(v)){return[]}};Graph.prototype.predecessors=function(v){var predsV=this._preds[v];if(predsV){return _.keys(predsV)}};Graph.prototype.successors=function(v){var sucsV=this._sucs[v];if(sucsV){return _.keys(sucsV)}};Graph.prototype.neighbors=function(v){var preds=this.predecessors(v);if(preds){return _.union(preds,this.successors(v))}};Graph.prototype.filterNodes=function(filter){var copy=new this.constructor({directed:this._isDirected,multigraph:this._isMultigraph,compound:this._isCompound});copy.setGraph(this.graph());_.each(this._nodes,function(value,v){if(filter(v)){copy.setNode(v,value)}},this);_.each(this._edgeObjs,function(e){if(copy.hasNode(e.v)&©.hasNode(e.w)){copy.setEdge(e,this.edge(e))}},this);var self=this;var parents={};function findParent(v){var parent=self.parent(v);if(parent===undefined||copy.hasNode(parent)){parents[v]=parent;return parent}else if(parent in parents){return parents[parent]}else{return findParent(parent)}}if(this._isCompound){_.each(copy.nodes(),function(v){copy.setParent(v,findParent(v))})}return copy};Graph.prototype.setDefaultEdgeLabel=function(newDefault){if(!_.isFunction(newDefault)){newDefault=_.constant(newDefault)}this._defaultEdgeLabelFn=newDefault;return this};Graph.prototype.edgeCount=function(){return this._edgeCount};Graph.prototype.edges=function(){return _.values(this._edgeObjs)};Graph.prototype.setPath=function(vs,value){var self=this,args=arguments;_.reduce(vs,function(v,w){if(args.length>1){self.setEdge(v,w,value)}else{self.setEdge(v,w)}return w});return this};Graph.prototype.setEdge=function(){var v,w,name,value,valueSpecified=false,arg0=arguments[0];if(typeof arg0==="object"&&arg0!==null&&"v"in arg0){v=arg0.v;w=arg0.w;name=arg0.name;if(arguments.length===2){value=arguments[1];valueSpecified=true}}else{v=arg0;w=arguments[1];name=arguments[3];if(arguments.length>2){value=arguments[2];valueSpecified=true}}v=""+v;w=""+w;if(!_.isUndefined(name)){name=""+name}var e=edgeArgsToId(this._isDirected,v,w,name);if(_.has(this._edgeLabels,e)){if(valueSpecified){this._edgeLabels[e]=value}return this}if(!_.isUndefined(name)&&!this._isMultigraph){throw new Error("Cannot set a named edge when isMultigraph = false")}this.setNode(v);this.setNode(w);this._edgeLabels[e]=valueSpecified?value:this._defaultEdgeLabelFn(v,w,name);var edgeObj=edgeArgsToObj(this._isDirected,v,w,name);v=edgeObj.v;w=edgeObj.w;Object.freeze(edgeObj);this._edgeObjs[e]=edgeObj;incrementOrInitEntry(this._preds[w],v);incrementOrInitEntry(this._sucs[v],w);this._in[w][e]=edgeObj;this._out[v][e]=edgeObj;this._edgeCount++;return this};Graph.prototype.edge=function(v,w,name){var e=arguments.length===1?edgeObjToId(this._isDirected,arguments[0]):edgeArgsToId(this._isDirected,v,w,name);return this._edgeLabels[e]};Graph.prototype.hasEdge=function(v,w,name){var e=arguments.length===1?edgeObjToId(this._isDirected,arguments[0]):edgeArgsToId(this._isDirected,v,w,name);return _.has(this._edgeLabels,e)};Graph.prototype.removeEdge=function(v,w,name){var e=arguments.length===1?edgeObjToId(this._isDirected,arguments[0]):edgeArgsToId(this._isDirected,v,w,name),edge=this._edgeObjs[e];if(edge){v=edge.v;w=edge.w;delete this._edgeLabels[e];delete this._edgeObjs[e];decrementOrRemoveEntry(this._preds[w],v);decrementOrRemoveEntry(this._sucs[v],w);delete this._in[w][e];delete this._out[v][e];this._edgeCount--}return this};Graph.prototype.inEdges=function(v,u){var inV=this._in[v];if(inV){var edges=_.values(inV);if(!u){return edges}return _.filter(edges,function(edge){return edge.v===u})}};Graph.prototype.outEdges=function(v,w){var outV=this._out[v];if(outV){var edges=_.values(outV);if(!w){return edges}return _.filter(edges,function(edge){return edge.w===w})}};Graph.prototype.nodeEdges=function(v,w){var inEdges=this.inEdges(v,w);if(inEdges){return inEdges.concat(this.outEdges(v,w))}};function incrementOrInitEntry(map,k){if(map[k]){map[k]++}else{map[k]=1}}function decrementOrRemoveEntry(map,k){if(!--map[k]){delete map[k]}}function edgeArgsToId(isDirected,v_,w_,name){var v=""+v_;var w=""+w_;if(!isDirected&&v>w){var tmp=v;v=w;w=tmp}return v+EDGE_KEY_DELIM+w+EDGE_KEY_DELIM+(_.isUndefined(name)?DEFAULT_EDGE_NAME:name)}function edgeArgsToObj(isDirected,v_,w_,name){var v=""+v_;var w=""+w_;if(!isDirected&&v>w){var tmp=v;v=w;w=tmp}var edgeObj={v:v,w:w};if(name){edgeObj.name=name}return edgeObj}function edgeObjToId(isDirected,edgeObj){return edgeArgsToId(isDirected,edgeObj.v,edgeObj.w,edgeObj.name)}},{"./lodash":20}],18:[function(require,module,exports){module.exports={Graph:require("./graph"),version:require("./version")}},{"./graph":17,"./version":21}],19:[function(require,module,exports){var _=require("./lodash"),Graph=require("./graph");module.exports={write:write,read:read};function write(g){var json={options:{directed:g.isDirected(),multigraph:g.isMultigraph(),compound:g.isCompound()},nodes:writeNodes(g),edges:writeEdges(g)};if(!_.isUndefined(g.graph())){json.value=_.clone(g.graph())}return json}function writeNodes(g){return _.map(g.nodes(),function(v){var nodeValue=g.node(v),parent=g.parent(v),node={v:v};if(!_.isUndefined(nodeValue)){node.value=nodeValue}if(!_.isUndefined(parent)){node.parent=parent}return node})}function writeEdges(g){return _.map(g.edges(),function(e){var edgeValue=g.edge(e),edge={v:e.v,w:e.w};if(!_.isUndefined(e.name)){edge.name=e.name}if(!_.isUndefined(edgeValue)){edge.value=edgeValue}return edge})}function read(json){var g=new Graph(json.options).setGraph(json.value);_.each(json.nodes,function(entry){g.setNode(entry.v,entry.value);if(entry.parent){g.setParent(entry.v,entry.parent)}});_.each(json.edges,function(entry){g.setEdge({v:entry.v,w:entry.w,name:entry.name},entry.value)});return g}},{"./graph":17,"./lodash":20}],20:[function(require,module,exports){var lodash;if(typeof require==="function"){try{lodash=require("lodash")}catch(e){}}if(!lodash){lodash=window._}module.exports=lodash},{lodash:undefined}],21:[function(require,module,exports){module.exports="1.0.7"},{}]},{},[1]); diff --git a/xstatic/pkg/graphlib/data/graphlib.js b/xstatic/pkg/graphlib/data/graphlib.js new file mode 100644 index 0000000..562da56 --- /dev/null +++ b/xstatic/pkg/graphlib/data/graphlib.js @@ -0,0 +1,13592 @@ +(function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o 0) { + v = pq.removeMin(); + vEntry = results[v]; + if (vEntry.distance === Number.POSITIVE_INFINITY) { + break; + } + + edgeFn(v).forEach(updateNeighbors); + } + + return results; +} + +},{"../data/priority-queue":16,"../lodash":20}],7:[function(require,module,exports){ +var _ = require("../lodash"), + tarjan = require("./tarjan"); + +module.exports = findCycles; + +function findCycles(g) { + return _.filter(tarjan(g), function(cmpt) { + return cmpt.length > 1 || (cmpt.length === 1 && g.hasEdge(cmpt[0], cmpt[0])); + }); +} + +},{"../lodash":20,"./tarjan":14}],8:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = floydWarshall; + +var DEFAULT_WEIGHT_FUNC = _.constant(1); + +function floydWarshall(g, weightFn, edgeFn) { + return runFloydWarshall(g, + weightFn || DEFAULT_WEIGHT_FUNC, + edgeFn || function(v) { return g.outEdges(v); }); +} + +function runFloydWarshall(g, weightFn, edgeFn) { + var results = {}, + nodes = g.nodes(); + + nodes.forEach(function(v) { + results[v] = {}; + results[v][v] = { distance: 0 }; + nodes.forEach(function(w) { + if (v !== w) { + results[v][w] = { distance: Number.POSITIVE_INFINITY }; + } + }); + edgeFn(v).forEach(function(edge) { + var w = edge.v === v ? edge.w : edge.v, + d = weightFn(edge); + results[v][w] = { distance: d, predecessor: v }; + }); + }); + + nodes.forEach(function(k) { + var rowK = results[k]; + nodes.forEach(function(i) { + var rowI = results[i]; + nodes.forEach(function(j) { + var ik = rowI[k]; + var kj = rowK[j]; + var ij = rowI[j]; + var altDistance = ik.distance + kj.distance; + if (altDistance < ij.distance) { + ij.distance = altDistance; + ij.predecessor = kj.predecessor; + } + }); + }); + }); + + return results; +} + +},{"../lodash":20}],9:[function(require,module,exports){ +module.exports = { + components: require("./components"), + dijkstra: require("./dijkstra"), + dijkstraAll: require("./dijkstra-all"), + findCycles: require("./find-cycles"), + floydWarshall: require("./floyd-warshall"), + isAcyclic: require("./is-acyclic"), + postorder: require("./postorder"), + preorder: require("./preorder"), + prim: require("./prim"), + tarjan: require("./tarjan"), + topsort: require("./topsort") +}; + +},{"./components":3,"./dijkstra":6,"./dijkstra-all":5,"./find-cycles":7,"./floyd-warshall":8,"./is-acyclic":10,"./postorder":11,"./preorder":12,"./prim":13,"./tarjan":14,"./topsort":15}],10:[function(require,module,exports){ +var topsort = require("./topsort"); + +module.exports = isAcyclic; + +function isAcyclic(g) { + try { + topsort(g); + } catch (e) { + if (e instanceof topsort.CycleException) { + return false; + } + throw e; + } + return true; +} + +},{"./topsort":15}],11:[function(require,module,exports){ +var dfs = require("./dfs"); + +module.exports = postorder; + +function postorder(g, vs) { + return dfs(g, vs, "post"); +} + +},{"./dfs":4}],12:[function(require,module,exports){ +var dfs = require("./dfs"); + +module.exports = preorder; + +function preorder(g, vs) { + return dfs(g, vs, "pre"); +} + +},{"./dfs":4}],13:[function(require,module,exports){ +var _ = require("../lodash"), + Graph = require("../graph"), + PriorityQueue = require("../data/priority-queue"); + +module.exports = prim; + +function prim(g, weightFunc) { + var result = new Graph(), + parents = {}, + pq = new PriorityQueue(), + v; + + function updateNeighbors(edge) { + var w = edge.v === v ? edge.w : edge.v, + pri = pq.priority(w); + if (pri !== undefined) { + var edgeWeight = weightFunc(edge); + if (edgeWeight < pri) { + parents[w] = v; + pq.decrease(w, edgeWeight); + } + } + } + + if (g.nodeCount() === 0) { + return result; + } + + _.each(g.nodes(), function(v) { + pq.add(v, Number.POSITIVE_INFINITY); + result.setNode(v); + }); + + // Start from an arbitrary node + pq.decrease(g.nodes()[0], 0); + + var init = false; + while (pq.size() > 0) { + v = pq.removeMin(); + if (_.has(parents, v)) { + result.setEdge(v, parents[v]); + } else if (init) { + throw new Error("Input graph is not connected: " + g); + } else { + init = true; + } + + g.nodeEdges(v).forEach(updateNeighbors); + } + + return result; +} + +},{"../data/priority-queue":16,"../graph":17,"../lodash":20}],14:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = tarjan; + +function tarjan(g) { + var index = 0, + stack = [], + visited = {}, // node id -> { onStack, lowlink, index } + results = []; + + function dfs(v) { + var entry = visited[v] = { + onStack: true, + lowlink: index, + index: index++ + }; + stack.push(v); + + g.successors(v).forEach(function(w) { + if (!_.has(visited, w)) { + dfs(w); + entry.lowlink = Math.min(entry.lowlink, visited[w].lowlink); + } else if (visited[w].onStack) { + entry.lowlink = Math.min(entry.lowlink, visited[w].index); + } + }); + + if (entry.lowlink === entry.index) { + var cmpt = [], + w; + do { + w = stack.pop(); + visited[w].onStack = false; + cmpt.push(w); + } while (v !== w); + results.push(cmpt); + } + } + + g.nodes().forEach(function(v) { + if (!_.has(visited, v)) { + dfs(v); + } + }); + + return results; +} + +},{"../lodash":20}],15:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = topsort; +topsort.CycleException = CycleException; + +function topsort(g) { + var visited = {}, + stack = {}, + results = []; + + function visit(node) { + if (_.has(stack, node)) { + throw new CycleException(); + } + + if (!_.has(visited, node)) { + stack[node] = true; + visited[node] = true; + _.each(g.predecessors(node), visit); + delete stack[node]; + results.push(node); + } + } + + _.each(g.sinks(), visit); + + if (_.size(visited) !== g.nodeCount()) { + throw new CycleException(); + } + + return results; +} + +function CycleException() {} + +},{"../lodash":20}],16:[function(require,module,exports){ +var _ = require("../lodash"); + +module.exports = PriorityQueue; + +/** + * A min-priority queue data structure. This algorithm is derived from Cormen, + * et al., "Introduction to Algorithms". The basic idea of a min-priority + * queue is that you can efficiently (in O(1) time) get the smallest key in + * the queue. Adding and removing elements takes O(log n) time. A key can + * have its priority decreased in O(log n) time. + */ +function PriorityQueue() { + this._arr = []; + this._keyIndices = {}; +} + +/** + * Returns the number of elements in the queue. Takes `O(1)` time. + */ +PriorityQueue.prototype.size = function() { + return this._arr.length; +}; + +/** + * Returns the keys that are in the queue. Takes `O(n)` time. + */ +PriorityQueue.prototype.keys = function() { + return this._arr.map(function(x) { return x.key; }); +}; + +/** + * Returns `true` if **key** is in the queue and `false` if not. + */ +PriorityQueue.prototype.has = function(key) { + return _.has(this._keyIndices, key); +}; + +/** + * Returns the priority for **key**. If **key** is not present in the queue + * then this function returns `undefined`. Takes `O(1)` time. + * + * @param {Object} key + */ +PriorityQueue.prototype.priority = function(key) { + var index = this._keyIndices[key]; + if (index !== undefined) { + return this._arr[index].priority; + } +}; + +/** + * Returns the key for the minimum element in this queue. If the queue is + * empty this function throws an Error. Takes `O(1)` time. + */ +PriorityQueue.prototype.min = function() { + if (this.size() === 0) { + throw new Error("Queue underflow"); + } + return this._arr[0].key; +}; + +/** + * Inserts a new key into the priority queue. If the key already exists in + * the queue this function returns `false`; otherwise it will return `true`. + * Takes `O(n)` time. + * + * @param {Object} key the key to add + * @param {Number} priority the initial priority for the key + */ +PriorityQueue.prototype.add = function(key, priority) { + var keyIndices = this._keyIndices; + key = String(key); + if (!_.has(keyIndices, key)) { + var arr = this._arr; + var index = arr.length; + keyIndices[key] = index; + arr.push({key: key, priority: priority}); + this._decrease(index); + return true; + } + return false; +}; + +/** + * Removes and returns the smallest key in the queue. Takes `O(log n)` time. + */ +PriorityQueue.prototype.removeMin = function() { + this._swap(0, this._arr.length - 1); + var min = this._arr.pop(); + delete this._keyIndices[min.key]; + this._heapify(0); + return min.key; +}; + +/** + * Decreases the priority for **key** to **priority**. If the new priority is + * greater than the previous priority, this function will throw an Error. + * + * @param {Object} key the key for which to raise priority + * @param {Number} priority the new priority for the key + */ +PriorityQueue.prototype.decrease = function(key, priority) { + var index = this._keyIndices[key]; + if (priority > this._arr[index].priority) { + throw new Error("New priority is greater than current priority. " + + "Key: " + key + " Old: " + this._arr[index].priority + " New: " + priority); + } + this._arr[index].priority = priority; + this._decrease(index); +}; + +PriorityQueue.prototype._heapify = function(i) { + var arr = this._arr; + var l = 2 * i, + r = l + 1, + largest = i; + if (l < arr.length) { + largest = arr[l].priority < arr[largest].priority ? l : largest; + if (r < arr.length) { + largest = arr[r].priority < arr[largest].priority ? r : largest; + } + if (largest !== i) { + this._swap(i, largest); + this._heapify(largest); + } + } +}; + +PriorityQueue.prototype._decrease = function(index) { + var arr = this._arr; + var priority = arr[index].priority; + var parent; + while (index !== 0) { + parent = index >> 1; + if (arr[parent].priority < priority) { + break; + } + this._swap(index, parent); + index = parent; + } +}; + +PriorityQueue.prototype._swap = function(i, j) { + var arr = this._arr; + var keyIndices = this._keyIndices; + var origArrI = arr[i]; + var origArrJ = arr[j]; + arr[i] = origArrJ; + arr[j] = origArrI; + keyIndices[origArrJ.key] = i; + keyIndices[origArrI.key] = j; +}; + +},{"../lodash":20}],17:[function(require,module,exports){ +"use strict"; + +var _ = require("./lodash"); + +module.exports = Graph; + +var DEFAULT_EDGE_NAME = "\x00", + GRAPH_NODE = "\x00", + EDGE_KEY_DELIM = "\x01"; + +// Implementation notes: +// +// * Node id query functions should return string ids for the nodes +// * Edge id query functions should return an "edgeObj", edge object, that is +// composed of enough information to uniquely identify an edge: {v, w, name}. +// * Internally we use an "edgeId", a stringified form of the edgeObj, to +// reference edges. This is because we need a performant way to look these +// edges up and, object properties, which have string keys, are the closest +// we're going to get to a performant hashtable in JavaScript. + +function Graph(opts) { + this._isDirected = _.has(opts, "directed") ? opts.directed : true; + this._isMultigraph = _.has(opts, "multigraph") ? opts.multigraph : false; + this._isCompound = _.has(opts, "compound") ? opts.compound : false; + + // Label for the graph itself + this._label = undefined; + + // Defaults to be set when creating a new node + this._defaultNodeLabelFn = _.constant(undefined); + + // Defaults to be set when creating a new edge + this._defaultEdgeLabelFn = _.constant(undefined); + + // v -> label + this._nodes = {}; + + if (this._isCompound) { + // v -> parent + this._parent = {}; + + // v -> children + this._children = {}; + this._children[GRAPH_NODE] = {}; + } + + // v -> edgeObj + this._in = {}; + + // u -> v -> Number + this._preds = {}; + + // v -> edgeObj + this._out = {}; + + // v -> w -> Number + this._sucs = {}; + + // e -> edgeObj + this._edgeObjs = {}; + + // e -> label + this._edgeLabels = {}; +} + +/* Number of nodes in the graph. Should only be changed by the implementation. */ +Graph.prototype._nodeCount = 0; + +/* Number of edges in the graph. Should only be changed by the implementation. */ +Graph.prototype._edgeCount = 0; + + +/* === Graph functions ========= */ + +Graph.prototype.isDirected = function() { + return this._isDirected; +}; + +Graph.prototype.isMultigraph = function() { + return this._isMultigraph; +}; + +Graph.prototype.isCompound = function() { + return this._isCompound; +}; + +Graph.prototype.setGraph = function(label) { + this._label = label; + return this; +}; + +Graph.prototype.graph = function() { + return this._label; +}; + + +/* === Node functions ========== */ + +Graph.prototype.setDefaultNodeLabel = function(newDefault) { + if (!_.isFunction(newDefault)) { + newDefault = _.constant(newDefault); + } + this._defaultNodeLabelFn = newDefault; + return this; +}; + +Graph.prototype.nodeCount = function() { + return this._nodeCount; +}; + +Graph.prototype.nodes = function() { + return _.keys(this._nodes); +}; + +Graph.prototype.sources = function() { + return _.filter(this.nodes(), function(v) { + return _.isEmpty(this._in[v]); + }, this); +}; + +Graph.prototype.sinks = function() { + return _.filter(this.nodes(), function(v) { + return _.isEmpty(this._out[v]); + }, this); +}; + +Graph.prototype.setNodes = function(vs, value) { + var args = arguments; + _.each(vs, function(v) { + if (args.length > 1) { + this.setNode(v, value); + } else { + this.setNode(v); + } + }, this); + return this; +}; + +Graph.prototype.setNode = function(v, value) { + if (_.has(this._nodes, v)) { + if (arguments.length > 1) { + this._nodes[v] = value; + } + return this; + } + + this._nodes[v] = arguments.length > 1 ? value : this._defaultNodeLabelFn(v); + if (this._isCompound) { + this._parent[v] = GRAPH_NODE; + this._children[v] = {}; + this._children[GRAPH_NODE][v] = true; + } + this._in[v] = {}; + this._preds[v] = {}; + this._out[v] = {}; + this._sucs[v] = {}; + ++this._nodeCount; + return this; +}; + +Graph.prototype.node = function(v) { + return this._nodes[v]; +}; + +Graph.prototype.hasNode = function(v) { + return _.has(this._nodes, v); +}; + +Graph.prototype.removeNode = function(v) { + var self = this; + if (_.has(this._nodes, v)) { + var removeEdge = function(e) { self.removeEdge(self._edgeObjs[e]); }; + delete this._nodes[v]; + if (this._isCompound) { + this._removeFromParentsChildList(v); + delete this._parent[v]; + _.each(this.children(v), function(child) { + this.setParent(child); + }, this); + delete this._children[v]; + } + _.each(_.keys(this._in[v]), removeEdge); + delete this._in[v]; + delete this._preds[v]; + _.each(_.keys(this._out[v]), removeEdge); + delete this._out[v]; + delete this._sucs[v]; + --this._nodeCount; + } + return this; +}; + +Graph.prototype.setParent = function(v, parent) { + if (!this._isCompound) { + throw new Error("Cannot set parent in a non-compound graph"); + } + + if (_.isUndefined(parent)) { + parent = GRAPH_NODE; + } else { + // Coerce parent to string + parent += ""; + for (var ancestor = parent; + !_.isUndefined(ancestor); + ancestor = this.parent(ancestor)) { + if (ancestor === v) { + throw new Error("Setting " + parent+ " as parent of " + v + + " would create create a cycle"); + } + } + + this.setNode(parent); + } + + this.setNode(v); + this._removeFromParentsChildList(v); + this._parent[v] = parent; + this._children[parent][v] = true; + return this; +}; + +Graph.prototype._removeFromParentsChildList = function(v) { + delete this._children[this._parent[v]][v]; +}; + +Graph.prototype.parent = function(v) { + if (this._isCompound) { + var parent = this._parent[v]; + if (parent !== GRAPH_NODE) { + return parent; + } + } +}; + +Graph.prototype.children = function(v) { + if (_.isUndefined(v)) { + v = GRAPH_NODE; + } + + if (this._isCompound) { + var children = this._children[v]; + if (children) { + return _.keys(children); + } + } else if (v === GRAPH_NODE) { + return this.nodes(); + } else if (this.hasNode(v)) { + return []; + } +}; + +Graph.prototype.predecessors = function(v) { + var predsV = this._preds[v]; + if (predsV) { + return _.keys(predsV); + } +}; + +Graph.prototype.successors = function(v) { + var sucsV = this._sucs[v]; + if (sucsV) { + return _.keys(sucsV); + } +}; + +Graph.prototype.neighbors = function(v) { + var preds = this.predecessors(v); + if (preds) { + return _.union(preds, this.successors(v)); + } +}; + +Graph.prototype.filterNodes = function(filter) { + var copy = new this.constructor({ + directed: this._isDirected, + multigraph: this._isMultigraph, + compound: this._isCompound + }); + + copy.setGraph(this.graph()); + + _.each(this._nodes, function(value, v) { + if (filter(v)) { + copy.setNode(v, value); + } + }, this); + + _.each(this._edgeObjs, function(e) { + if (copy.hasNode(e.v) && copy.hasNode(e.w)) { + copy.setEdge(e, this.edge(e)); + } + }, this); + + var self = this; + var parents = {}; + function findParent(v) { + var parent = self.parent(v); + if (parent === undefined || copy.hasNode(parent)) { + parents[v] = parent; + return parent; + } else if (parent in parents) { + return parents[parent]; + } else { + return findParent(parent); + } + } + + if (this._isCompound) { + _.each(copy.nodes(), function(v) { + copy.setParent(v, findParent(v)); + }); + } + + return copy; +}; + +/* === Edge functions ========== */ + +Graph.prototype.setDefaultEdgeLabel = function(newDefault) { + if (!_.isFunction(newDefault)) { + newDefault = _.constant(newDefault); + } + this._defaultEdgeLabelFn = newDefault; + return this; +}; + +Graph.prototype.edgeCount = function() { + return this._edgeCount; +}; + +Graph.prototype.edges = function() { + return _.values(this._edgeObjs); +}; + +Graph.prototype.setPath = function(vs, value) { + var self = this, + args = arguments; + _.reduce(vs, function(v, w) { + if (args.length > 1) { + self.setEdge(v, w, value); + } else { + self.setEdge(v, w); + } + return w; + }); + return this; +}; + +/* + * setEdge(v, w, [value, [name]]) + * setEdge({ v, w, [name] }, [value]) + */ +Graph.prototype.setEdge = function() { + var v, w, name, value, + valueSpecified = false, + arg0 = arguments[0]; + + if (typeof arg0 === "object" && arg0 !== null && "v" in arg0) { + v = arg0.v; + w = arg0.w; + name = arg0.name; + if (arguments.length === 2) { + value = arguments[1]; + valueSpecified = true; + } + } else { + v = arg0; + w = arguments[1]; + name = arguments[3]; + if (arguments.length > 2) { + value = arguments[2]; + valueSpecified = true; + } + } + + v = "" + v; + w = "" + w; + if (!_.isUndefined(name)) { + name = "" + name; + } + + var e = edgeArgsToId(this._isDirected, v, w, name); + if (_.has(this._edgeLabels, e)) { + if (valueSpecified) { + this._edgeLabels[e] = value; + } + return this; + } + + if (!_.isUndefined(name) && !this._isMultigraph) { + throw new Error("Cannot set a named edge when isMultigraph = false"); + } + + // It didn't exist, so we need to create it. + // First ensure the nodes exist. + this.setNode(v); + this.setNode(w); + + this._edgeLabels[e] = valueSpecified ? value : this._defaultEdgeLabelFn(v, w, name); + + var edgeObj = edgeArgsToObj(this._isDirected, v, w, name); + // Ensure we add undirected edges in a consistent way. + v = edgeObj.v; + w = edgeObj.w; + + Object.freeze(edgeObj); + this._edgeObjs[e] = edgeObj; + incrementOrInitEntry(this._preds[w], v); + incrementOrInitEntry(this._sucs[v], w); + this._in[w][e] = edgeObj; + this._out[v][e] = edgeObj; + this._edgeCount++; + return this; +}; + +Graph.prototype.edge = function(v, w, name) { + var e = (arguments.length === 1 + ? edgeObjToId(this._isDirected, arguments[0]) + : edgeArgsToId(this._isDirected, v, w, name)); + return this._edgeLabels[e]; +}; + +Graph.prototype.hasEdge = function(v, w, name) { + var e = (arguments.length === 1 + ? edgeObjToId(this._isDirected, arguments[0]) + : edgeArgsToId(this._isDirected, v, w, name)); + return _.has(this._edgeLabels, e); +}; + +Graph.prototype.removeEdge = function(v, w, name) { + var e = (arguments.length === 1 + ? edgeObjToId(this._isDirected, arguments[0]) + : edgeArgsToId(this._isDirected, v, w, name)), + edge = this._edgeObjs[e]; + if (edge) { + v = edge.v; + w = edge.w; + delete this._edgeLabels[e]; + delete this._edgeObjs[e]; + decrementOrRemoveEntry(this._preds[w], v); + decrementOrRemoveEntry(this._sucs[v], w); + delete this._in[w][e]; + delete this._out[v][e]; + this._edgeCount--; + } + return this; +}; + +Graph.prototype.inEdges = function(v, u) { + var inV = this._in[v]; + if (inV) { + var edges = _.values(inV); + if (!u) { + return edges; + } + return _.filter(edges, function(edge) { return edge.v === u; }); + } +}; + +Graph.prototype.outEdges = function(v, w) { + var outV = this._out[v]; + if (outV) { + var edges = _.values(outV); + if (!w) { + return edges; + } + return _.filter(edges, function(edge) { return edge.w === w; }); + } +}; + +Graph.prototype.nodeEdges = function(v, w) { + var inEdges = this.inEdges(v, w); + if (inEdges) { + return inEdges.concat(this.outEdges(v, w)); + } +}; + +function incrementOrInitEntry(map, k) { + if (map[k]) { + map[k]++; + } else { + map[k] = 1; + } +} + +function decrementOrRemoveEntry(map, k) { + if (!--map[k]) { delete map[k]; } +} + +function edgeArgsToId(isDirected, v_, w_, name) { + var v = "" + v_; + var w = "" + w_; + if (!isDirected && v > w) { + var tmp = v; + v = w; + w = tmp; + } + return v + EDGE_KEY_DELIM + w + EDGE_KEY_DELIM + + (_.isUndefined(name) ? DEFAULT_EDGE_NAME : name); +} + +function edgeArgsToObj(isDirected, v_, w_, name) { + var v = "" + v_; + var w = "" + w_; + if (!isDirected && v > w) { + var tmp = v; + v = w; + w = tmp; + } + var edgeObj = { v: v, w: w }; + if (name) { + edgeObj.name = name; + } + return edgeObj; +} + +function edgeObjToId(isDirected, edgeObj) { + return edgeArgsToId(isDirected, edgeObj.v, edgeObj.w, edgeObj.name); +} + +},{"./lodash":20}],18:[function(require,module,exports){ +// Includes only the "core" of graphlib +module.exports = { + Graph: require("./graph"), + version: require("./version") +}; + +},{"./graph":17,"./version":21}],19:[function(require,module,exports){ +var _ = require("./lodash"), + Graph = require("./graph"); + +module.exports = { + write: write, + read: read +}; + +function write(g) { + var json = { + options: { + directed: g.isDirected(), + multigraph: g.isMultigraph(), + compound: g.isCompound() + }, + nodes: writeNodes(g), + edges: writeEdges(g) + }; + if (!_.isUndefined(g.graph())) { + json.value = _.clone(g.graph()); + } + return json; +} + +function writeNodes(g) { + return _.map(g.nodes(), function(v) { + var nodeValue = g.node(v), + parent = g.parent(v), + node = { v: v }; + if (!_.isUndefined(nodeValue)) { + node.value = nodeValue; + } + if (!_.isUndefined(parent)) { + node.parent = parent; + } + return node; + }); +} + +function writeEdges(g) { + return _.map(g.edges(), function(e) { + var edgeValue = g.edge(e), + edge = { v: e.v, w: e.w }; + if (!_.isUndefined(e.name)) { + edge.name = e.name; + } + if (!_.isUndefined(edgeValue)) { + edge.value = edgeValue; + } + return edge; + }); +} + +function read(json) { + var g = new Graph(json.options).setGraph(json.value); + _.each(json.nodes, function(entry) { + g.setNode(entry.v, entry.value); + if (entry.parent) { + g.setParent(entry.v, entry.parent); + } + }); + _.each(json.edges, function(entry) { + g.setEdge({ v: entry.v, w: entry.w, name: entry.name }, entry.value); + }); + return g; +} + +},{"./graph":17,"./lodash":20}],20:[function(require,module,exports){ +/* global window */ + +var lodash; + +if (typeof require === "function") { + try { + lodash = require("lodash"); + } catch (e) {} +} + +if (!lodash) { + lodash = window._; +} + +module.exports = lodash; + +},{"lodash":22}],21:[function(require,module,exports){ +module.exports = '1.0.7'; + +},{}],22:[function(require,module,exports){ +(function (global){ +/** + * @license + * lodash 3.10.0 (Custom Build) + * Build: `lodash modern -d -o ./index.js` + * Copyright 2012-2015 The Dojo Foundation + * Based on Underscore.js 1.8.3 + * Copyright 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors + * Available under MIT license + */ +;(function() { + + /** Used as a safe reference for `undefined` in pre-ES5 environments. */ + var undefined; + + /** Used as the semantic version number. */ + var VERSION = '3.10.0'; + + /** Used to compose bitmasks for wrapper metadata. */ + var BIND_FLAG = 1, + BIND_KEY_FLAG = 2, + CURRY_BOUND_FLAG = 4, + CURRY_FLAG = 8, + CURRY_RIGHT_FLAG = 16, + PARTIAL_FLAG = 32, + PARTIAL_RIGHT_FLAG = 64, + ARY_FLAG = 128, + REARG_FLAG = 256; + + /** Used as default options for `_.trunc`. */ + var DEFAULT_TRUNC_LENGTH = 30, + DEFAULT_TRUNC_OMISSION = '...'; + + /** Used to detect when a function becomes hot. */ + var HOT_COUNT = 150, + HOT_SPAN = 16; + + /** Used as the size to enable large array optimizations. */ + var LARGE_ARRAY_SIZE = 200; + + /** Used to indicate the type of lazy iteratees. */ + var LAZY_FILTER_FLAG = 1, + LAZY_MAP_FLAG = 2; + + /** Used as the `TypeError` message for "Functions" methods. */ + var FUNC_ERROR_TEXT = 'Expected a function'; + + /** Used as the internal argument placeholder. */ + var PLACEHOLDER = '__lodash_placeholder__'; + + /** `Object#toString` result references. */ + var argsTag = '[object Arguments]', + arrayTag = '[object Array]', + boolTag = '[object Boolean]', + dateTag = '[object Date]', + errorTag = '[object Error]', + funcTag = '[object Function]', + mapTag = '[object Map]', + numberTag = '[object Number]', + objectTag = '[object Object]', + regexpTag = '[object RegExp]', + setTag = '[object Set]', + stringTag = '[object String]', + weakMapTag = '[object WeakMap]'; + + var arrayBufferTag = '[object ArrayBuffer]', + float32Tag = '[object Float32Array]', + float64Tag = '[object Float64Array]', + int8Tag = '[object Int8Array]', + int16Tag = '[object Int16Array]', + int32Tag = '[object Int32Array]', + uint8Tag = '[object Uint8Array]', + uint8ClampedTag = '[object Uint8ClampedArray]', + uint16Tag = '[object Uint16Array]', + uint32Tag = '[object Uint32Array]'; + + /** Used to match empty string literals in compiled template source. */ + var reEmptyStringLeading = /\b__p \+= '';/g, + reEmptyStringMiddle = /\b(__p \+=) '' \+/g, + reEmptyStringTrailing = /(__e\(.*?\)|\b__t\)) \+\n'';/g; + + /** Used to match HTML entities and HTML characters. */ + var reEscapedHtml = /&(?:amp|lt|gt|quot|#39|#96);/g, + reUnescapedHtml = /[&<>"'`]/g, + reHasEscapedHtml = RegExp(reEscapedHtml.source), + reHasUnescapedHtml = RegExp(reUnescapedHtml.source); + + /** Used to match template delimiters. */ + var reEscape = /<%-([\s\S]+?)%>/g, + reEvaluate = /<%([\s\S]+?)%>/g, + reInterpolate = /<%=([\s\S]+?)%>/g; + + /** Used to match property names within property paths. */ + var reIsDeepProp = /\.|\[(?:[^[\]]*|(["'])(?:(?!\1)[^\n\\]|\\.)*?\1)\]/, + reIsPlainProp = /^\w*$/, + rePropName = /[^.[\]]+|\[(?:(-?\d+(?:\.\d+)?)|(["'])((?:(?!\2)[^\n\\]|\\.)*?)\2)\]/g; + + /** + * Used to match `RegExp` [syntax characters](http://ecma-international.org/ecma-262/6.0/#sec-patterns) + * and those outlined by [`EscapeRegExpPattern`](http://ecma-international.org/ecma-262/6.0/#sec-escaperegexppattern). + */ + var reRegExpChars = /^[:!,]|[\\^$.*+?()[\]{}|\/]|(^[0-9a-fA-Fnrtuvx])|([\n\r\u2028\u2029])/g, + reHasRegExpChars = RegExp(reRegExpChars.source); + + /** Used to match [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks). */ + var reComboMark = /[\u0300-\u036f\ufe20-\ufe23]/g; + + /** Used to match backslashes in property paths. */ + var reEscapeChar = /\\(\\)?/g; + + /** Used to match [ES template delimiters](http://ecma-international.org/ecma-262/6.0/#sec-template-literal-lexical-components). */ + var reEsTemplate = /\$\{([^\\}]*(?:\\.[^\\}]*)*)\}/g; + + /** Used to match `RegExp` flags from their coerced string values. */ + var reFlags = /\w*$/; + + /** Used to detect hexadecimal string values. */ + var reHasHexPrefix = /^0[xX]/; + + /** Used to detect host constructors (Safari > 5). */ + var reIsHostCtor = /^\[object .+?Constructor\]$/; + + /** Used to detect unsigned integer values. */ + var reIsUint = /^\d+$/; + + /** Used to match latin-1 supplementary letters (excluding mathematical operators). */ + var reLatin1 = /[\xc0-\xd6\xd8-\xde\xdf-\xf6\xf8-\xff]/g; + + /** Used to ensure capturing order of template delimiters. */ + var reNoMatch = /($^)/; + + /** Used to match unescaped characters in compiled string literals. */ + var reUnescapedString = /['\n\r\u2028\u2029\\]/g; + + /** Used to match words to create compound words. */ + var reWords = (function() { + var upper = '[A-Z\\xc0-\\xd6\\xd8-\\xde]', + lower = '[a-z\\xdf-\\xf6\\xf8-\\xff]+'; + + return RegExp(upper + '+(?=' + upper + lower + ')|' + upper + '?' + lower + '|' + upper + '+|[0-9]+', 'g'); + }()); + + /** Used to assign default `context` object properties. */ + var contextProps = [ + 'Array', 'ArrayBuffer', 'Date', 'Error', 'Float32Array', 'Float64Array', + 'Function', 'Int8Array', 'Int16Array', 'Int32Array', 'Math', 'Number', + 'Object', 'RegExp', 'Set', 'String', '_', 'clearTimeout', 'isFinite', + 'parseFloat', 'parseInt', 'setTimeout', 'TypeError', 'Uint8Array', + 'Uint8ClampedArray', 'Uint16Array', 'Uint32Array', 'WeakMap' + ]; + + /** Used to make template sourceURLs easier to identify. */ + var templateCounter = -1; + + /** Used to identify `toStringTag` values of typed arrays. */ + var typedArrayTags = {}; + typedArrayTags[float32Tag] = typedArrayTags[float64Tag] = + typedArrayTags[int8Tag] = typedArrayTags[int16Tag] = + typedArrayTags[int32Tag] = typedArrayTags[uint8Tag] = + typedArrayTags[uint8ClampedTag] = typedArrayTags[uint16Tag] = + typedArrayTags[uint32Tag] = true; + typedArrayTags[argsTag] = typedArrayTags[arrayTag] = + typedArrayTags[arrayBufferTag] = typedArrayTags[boolTag] = + typedArrayTags[dateTag] = typedArrayTags[errorTag] = + typedArrayTags[funcTag] = typedArrayTags[mapTag] = + typedArrayTags[numberTag] = typedArrayTags[objectTag] = + typedArrayTags[regexpTag] = typedArrayTags[setTag] = + typedArrayTags[stringTag] = typedArrayTags[weakMapTag] = false; + + /** Used to identify `toStringTag` values supported by `_.clone`. */ + var cloneableTags = {}; + cloneableTags[argsTag] = cloneableTags[arrayTag] = + cloneableTags[arrayBufferTag] = cloneableTags[boolTag] = + cloneableTags[dateTag] = cloneableTags[float32Tag] = + cloneableTags[float64Tag] = cloneableTags[int8Tag] = + cloneableTags[int16Tag] = cloneableTags[int32Tag] = + cloneableTags[numberTag] = cloneableTags[objectTag] = + cloneableTags[regexpTag] = cloneableTags[stringTag] = + cloneableTags[uint8Tag] = cloneableTags[uint8ClampedTag] = + cloneableTags[uint16Tag] = cloneableTags[uint32Tag] = true; + cloneableTags[errorTag] = cloneableTags[funcTag] = + cloneableTags[mapTag] = cloneableTags[setTag] = + cloneableTags[weakMapTag] = false; + + /** Used to map latin-1 supplementary letters to basic latin letters. */ + var deburredLetters = { + '\xc0': 'A', '\xc1': 'A', '\xc2': 'A', '\xc3': 'A', '\xc4': 'A', '\xc5': 'A', + '\xe0': 'a', '\xe1': 'a', '\xe2': 'a', '\xe3': 'a', '\xe4': 'a', '\xe5': 'a', + '\xc7': 'C', '\xe7': 'c', + '\xd0': 'D', '\xf0': 'd', + '\xc8': 'E', '\xc9': 'E', '\xca': 'E', '\xcb': 'E', + '\xe8': 'e', '\xe9': 'e', '\xea': 'e', '\xeb': 'e', + '\xcC': 'I', '\xcd': 'I', '\xce': 'I', '\xcf': 'I', + '\xeC': 'i', '\xed': 'i', '\xee': 'i', '\xef': 'i', + '\xd1': 'N', '\xf1': 'n', + '\xd2': 'O', '\xd3': 'O', '\xd4': 'O', '\xd5': 'O', '\xd6': 'O', '\xd8': 'O', + '\xf2': 'o', '\xf3': 'o', '\xf4': 'o', '\xf5': 'o', '\xf6': 'o', '\xf8': 'o', + '\xd9': 'U', '\xda': 'U', '\xdb': 'U', '\xdc': 'U', + '\xf9': 'u', '\xfa': 'u', '\xfb': 'u', '\xfc': 'u', + '\xdd': 'Y', '\xfd': 'y', '\xff': 'y', + '\xc6': 'Ae', '\xe6': 'ae', + '\xde': 'Th', '\xfe': 'th', + '\xdf': 'ss' + }; + + /** Used to map characters to HTML entities. */ + var htmlEscapes = { + '&': '&', + '<': '<', + '>': '>', + '"': '"', + "'": ''', + '`': '`' + }; + + /** Used to map HTML entities to characters. */ + var htmlUnescapes = { + '&': '&', + '<': '<', + '>': '>', + '"': '"', + ''': "'", + '`': '`' + }; + + /** Used to determine if values are of the language type `Object`. */ + var objectTypes = { + 'function': true, + 'object': true + }; + + /** Used to escape characters for inclusion in compiled regexes. */ + var regexpEscapes = { + '0': 'x30', '1': 'x31', '2': 'x32', '3': 'x33', '4': 'x34', + '5': 'x35', '6': 'x36', '7': 'x37', '8': 'x38', '9': 'x39', + 'A': 'x41', 'B': 'x42', 'C': 'x43', 'D': 'x44', 'E': 'x45', 'F': 'x46', + 'a': 'x61', 'b': 'x62', 'c': 'x63', 'd': 'x64', 'e': 'x65', 'f': 'x66', + 'n': 'x6e', 'r': 'x72', 't': 'x74', 'u': 'x75', 'v': 'x76', 'x': 'x78' + }; + + /** Used to escape characters for inclusion in compiled string literals. */ + var stringEscapes = { + '\\': '\\', + "'": "'", + '\n': 'n', + '\r': 'r', + '\u2028': 'u2028', + '\u2029': 'u2029' + }; + + /** Detect free variable `exports`. */ + var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports; + + /** Detect free variable `module`. */ + var freeModule = objectTypes[typeof module] && module && !module.nodeType && module; + + /** Detect free variable `global` from Node.js. */ + var freeGlobal = freeExports && freeModule && typeof global == 'object' && global && global.Object && global; + + /** Detect free variable `self`. */ + var freeSelf = objectTypes[typeof self] && self && self.Object && self; + + /** Detect free variable `window`. */ + var freeWindow = objectTypes[typeof window] && window && window.Object && window; + + /** Detect the popular CommonJS extension `module.exports`. */ + var moduleExports = freeModule && freeModule.exports === freeExports && freeExports; + + /** + * Used as a reference to the global object. + * + * The `this` value is used if it's the global object to avoid Greasemonkey's + * restricted `window` object, otherwise the `window` object is used. + */ + var root = freeGlobal || ((freeWindow !== (this && this.window)) && freeWindow) || freeSelf || this; + + /*--------------------------------------------------------------------------*/ + + /** + * The base implementation of `compareAscending` which compares values and + * sorts them in ascending order without guaranteeing a stable sort. + * + * @private + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {number} Returns the sort order indicator for `value`. + */ + function baseCompareAscending(value, other) { + if (value !== other) { + var valIsNull = value === null, + valIsUndef = value === undefined, + valIsReflexive = value === value; + + var othIsNull = other === null, + othIsUndef = other === undefined, + othIsReflexive = other === other; + + if ((value > other && !othIsNull) || !valIsReflexive || + (valIsNull && !othIsUndef && othIsReflexive) || + (valIsUndef && othIsReflexive)) { + return 1; + } + if ((value < other && !valIsNull) || !othIsReflexive || + (othIsNull && !valIsUndef && valIsReflexive) || + (othIsUndef && valIsReflexive)) { + return -1; + } + } + return 0; + } + + /** + * The base implementation of `_.findIndex` and `_.findLastIndex` without + * support for callback shorthands and `this` binding. + * + * @private + * @param {Array} array The array to search. + * @param {Function} predicate The function invoked per iteration. + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {number} Returns the index of the matched value, else `-1`. + */ + function baseFindIndex(array, predicate, fromRight) { + var length = array.length, + index = fromRight ? length : -1; + + while ((fromRight ? index-- : ++index < length)) { + if (predicate(array[index], index, array)) { + return index; + } + } + return -1; + } + + /** + * The base implementation of `_.indexOf` without support for binary searches. + * + * @private + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {number} fromIndex The index to search from. + * @returns {number} Returns the index of the matched value, else `-1`. + */ + function baseIndexOf(array, value, fromIndex) { + if (value !== value) { + return indexOfNaN(array, fromIndex); + } + var index = fromIndex - 1, + length = array.length; + + while (++index < length) { + if (array[index] === value) { + return index; + } + } + return -1; + } + + /** + * The base implementation of `_.isFunction` without support for environments + * with incorrect `typeof` results. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + */ + function baseIsFunction(value) { + // Avoid a Chakra JIT bug in compatibility modes of IE 11. + // See https://github.com/jashkenas/underscore/issues/1621 for more details. + return typeof value == 'function' || false; + } + + /** + * Converts `value` to a string if it's not one. An empty string is returned + * for `null` or `undefined` values. + * + * @private + * @param {*} value The value to process. + * @returns {string} Returns the string. + */ + function baseToString(value) { + return value == null ? '' : (value + ''); + } + + /** + * Used by `_.trim` and `_.trimLeft` to get the index of the first character + * of `string` that is not found in `chars`. + * + * @private + * @param {string} string The string to inspect. + * @param {string} chars The characters to find. + * @returns {number} Returns the index of the first character not found in `chars`. + */ + function charsLeftIndex(string, chars) { + var index = -1, + length = string.length; + + while (++index < length && chars.indexOf(string.charAt(index)) > -1) {} + return index; + } + + /** + * Used by `_.trim` and `_.trimRight` to get the index of the last character + * of `string` that is not found in `chars`. + * + * @private + * @param {string} string The string to inspect. + * @param {string} chars The characters to find. + * @returns {number} Returns the index of the last character not found in `chars`. + */ + function charsRightIndex(string, chars) { + var index = string.length; + + while (index-- && chars.indexOf(string.charAt(index)) > -1) {} + return index; + } + + /** + * Used by `_.sortBy` to compare transformed elements of a collection and stable + * sort them in ascending order. + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @returns {number} Returns the sort order indicator for `object`. + */ + function compareAscending(object, other) { + return baseCompareAscending(object.criteria, other.criteria) || (object.index - other.index); + } + + /** + * Used by `_.sortByOrder` to compare multiple properties of a value to another + * and stable sort them. + * + * If `orders` is unspecified, all valuess are sorted in ascending order. Otherwise, + * a value is sorted in ascending order if its corresponding order is "asc", and + * descending if "desc". + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @param {boolean[]} orders The order to sort by for each property. + * @returns {number} Returns the sort order indicator for `object`. + */ + function compareMultiple(object, other, orders) { + var index = -1, + objCriteria = object.criteria, + othCriteria = other.criteria, + length = objCriteria.length, + ordersLength = orders.length; + + while (++index < length) { + var result = baseCompareAscending(objCriteria[index], othCriteria[index]); + if (result) { + if (index >= ordersLength) { + return result; + } + var order = orders[index]; + return result * ((order === 'asc' || order === true) ? 1 : -1); + } + } + // Fixes an `Array#sort` bug in the JS engine embedded in Adobe applications + // that causes it, under certain circumstances, to provide the same value for + // `object` and `other`. See https://github.com/jashkenas/underscore/pull/1247 + // for more details. + // + // This also ensures a stable sort in V8 and other engines. + // See https://code.google.com/p/v8/issues/detail?id=90 for more details. + return object.index - other.index; + } + + /** + * Used by `_.deburr` to convert latin-1 supplementary letters to basic latin letters. + * + * @private + * @param {string} letter The matched letter to deburr. + * @returns {string} Returns the deburred letter. + */ + function deburrLetter(letter) { + return deburredLetters[letter]; + } + + /** + * Used by `_.escape` to convert characters to HTML entities. + * + * @private + * @param {string} chr The matched character to escape. + * @returns {string} Returns the escaped character. + */ + function escapeHtmlChar(chr) { + return htmlEscapes[chr]; + } + + /** + * Used by `_.escapeRegExp` to escape characters for inclusion in compiled regexes. + * + * @private + * @param {string} chr The matched character to escape. + * @param {string} leadingChar The capture group for a leading character. + * @param {string} whitespaceChar The capture group for a whitespace character. + * @returns {string} Returns the escaped character. + */ + function escapeRegExpChar(chr, leadingChar, whitespaceChar) { + if (leadingChar) { + chr = regexpEscapes[chr]; + } else if (whitespaceChar) { + chr = stringEscapes[chr]; + } + return '\\' + chr; + } + + /** + * Used by `_.template` to escape characters for inclusion in compiled string literals. + * + * @private + * @param {string} chr The matched character to escape. + * @returns {string} Returns the escaped character. + */ + function escapeStringChar(chr) { + return '\\' + stringEscapes[chr]; + } + + /** + * Gets the index at which the first occurrence of `NaN` is found in `array`. + * + * @private + * @param {Array} array The array to search. + * @param {number} fromIndex The index to search from. + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {number} Returns the index of the matched `NaN`, else `-1`. + */ + function indexOfNaN(array, fromIndex, fromRight) { + var length = array.length, + index = fromIndex + (fromRight ? 0 : -1); + + while ((fromRight ? index-- : ++index < length)) { + var other = array[index]; + if (other !== other) { + return index; + } + } + return -1; + } + + /** + * Checks if `value` is object-like. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is object-like, else `false`. + */ + function isObjectLike(value) { + return !!value && typeof value == 'object'; + } + + /** + * Used by `trimmedLeftIndex` and `trimmedRightIndex` to determine if a + * character code is whitespace. + * + * @private + * @param {number} charCode The character code to inspect. + * @returns {boolean} Returns `true` if `charCode` is whitespace, else `false`. + */ + function isSpace(charCode) { + return ((charCode <= 160 && (charCode >= 9 && charCode <= 13) || charCode == 32 || charCode == 160) || charCode == 5760 || charCode == 6158 || + (charCode >= 8192 && (charCode <= 8202 || charCode == 8232 || charCode == 8233 || charCode == 8239 || charCode == 8287 || charCode == 12288 || charCode == 65279))); + } + + /** + * Replaces all `placeholder` elements in `array` with an internal placeholder + * and returns an array of their indexes. + * + * @private + * @param {Array} array The array to modify. + * @param {*} placeholder The placeholder to replace. + * @returns {Array} Returns the new array of placeholder indexes. + */ + function replaceHolders(array, placeholder) { + var index = -1, + length = array.length, + resIndex = -1, + result = []; + + while (++index < length) { + if (array[index] === placeholder) { + array[index] = PLACEHOLDER; + result[++resIndex] = index; + } + } + return result; + } + + /** + * An implementation of `_.uniq` optimized for sorted arrays without support + * for callback shorthands and `this` binding. + * + * @private + * @param {Array} array The array to inspect. + * @param {Function} [iteratee] The function invoked per iteration. + * @returns {Array} Returns the new duplicate-value-free array. + */ + function sortedUniq(array, iteratee) { + var seen, + index = -1, + length = array.length, + resIndex = -1, + result = []; + + while (++index < length) { + var value = array[index], + computed = iteratee ? iteratee(value, index, array) : value; + + if (!index || seen !== computed) { + seen = computed; + result[++resIndex] = value; + } + } + return result; + } + + /** + * Used by `_.trim` and `_.trimLeft` to get the index of the first non-whitespace + * character of `string`. + * + * @private + * @param {string} string The string to inspect. + * @returns {number} Returns the index of the first non-whitespace character. + */ + function trimmedLeftIndex(string) { + var index = -1, + length = string.length; + + while (++index < length && isSpace(string.charCodeAt(index))) {} + return index; + } + + /** + * Used by `_.trim` and `_.trimRight` to get the index of the last non-whitespace + * character of `string`. + * + * @private + * @param {string} string The string to inspect. + * @returns {number} Returns the index of the last non-whitespace character. + */ + function trimmedRightIndex(string) { + var index = string.length; + + while (index-- && isSpace(string.charCodeAt(index))) {} + return index; + } + + /** + * Used by `_.unescape` to convert HTML entities to characters. + * + * @private + * @param {string} chr The matched character to unescape. + * @returns {string} Returns the unescaped character. + */ + function unescapeHtmlChar(chr) { + return htmlUnescapes[chr]; + } + + /*--------------------------------------------------------------------------*/ + + /** + * Create a new pristine `lodash` function using the given `context` object. + * + * @static + * @memberOf _ + * @category Utility + * @param {Object} [context=root] The context object. + * @returns {Function} Returns a new `lodash` function. + * @example + * + * _.mixin({ 'foo': _.constant('foo') }); + * + * var lodash = _.runInContext(); + * lodash.mixin({ 'bar': lodash.constant('bar') }); + * + * _.isFunction(_.foo); + * // => true + * _.isFunction(_.bar); + * // => false + * + * lodash.isFunction(lodash.foo); + * // => false + * lodash.isFunction(lodash.bar); + * // => true + * + * // using `context` to mock `Date#getTime` use in `_.now` + * var mock = _.runInContext({ + * 'Date': function() { + * return { 'getTime': getTimeMock }; + * } + * }); + * + * // or creating a suped-up `defer` in Node.js + * var defer = _.runInContext({ 'setTimeout': setImmediate }).defer; + */ + function runInContext(context) { + // Avoid issues with some ES3 environments that attempt to use values, named + // after built-in constructors like `Object`, for the creation of literals. + // ES5 clears this up by stating that literals must use built-in constructors. + // See https://es5.github.io/#x11.1.5 for more details. + context = context ? _.defaults(root.Object(), context, _.pick(root, contextProps)) : root; + + /** Native constructor references. */ + var Array = context.Array, + Date = context.Date, + Error = context.Error, + Function = context.Function, + Math = context.Math, + Number = context.Number, + Object = context.Object, + RegExp = context.RegExp, + String = context.String, + TypeError = context.TypeError; + + /** Used for native method references. */ + var arrayProto = Array.prototype, + objectProto = Object.prototype, + stringProto = String.prototype; + + /** Used to resolve the decompiled source of functions. */ + var fnToString = Function.prototype.toString; + + /** Used to check objects for own properties. */ + var hasOwnProperty = objectProto.hasOwnProperty; + + /** Used to generate unique IDs. */ + var idCounter = 0; + + /** + * Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring) + * of values. + */ + var objToString = objectProto.toString; + + /** Used to restore the original `_` reference in `_.noConflict`. */ + var oldDash = root._; + + /** Used to detect if a method is native. */ + var reIsNative = RegExp('^' + + fnToString.call(hasOwnProperty).replace(/[\\^$.*+?()[\]{}|]/g, '\\$&') + .replace(/hasOwnProperty|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?') + '$' + ); + + /** Native method references. */ + var ArrayBuffer = context.ArrayBuffer, + clearTimeout = context.clearTimeout, + parseFloat = context.parseFloat, + pow = Math.pow, + propertyIsEnumerable = objectProto.propertyIsEnumerable, + Set = getNative(context, 'Set'), + setTimeout = context.setTimeout, + splice = arrayProto.splice, + Uint8Array = context.Uint8Array, + WeakMap = getNative(context, 'WeakMap'); + + /* Native method references for those with the same name as other `lodash` methods. */ + var nativeCeil = Math.ceil, + nativeCreate = getNative(Object, 'create'), + nativeFloor = Math.floor, + nativeIsArray = getNative(Array, 'isArray'), + nativeIsFinite = context.isFinite, + nativeKeys = getNative(Object, 'keys'), + nativeMax = Math.max, + nativeMin = Math.min, + nativeNow = getNative(Date, 'now'), + nativeParseInt = context.parseInt, + nativeRandom = Math.random; + + /** Used as references for `-Infinity` and `Infinity`. */ + var NEGATIVE_INFINITY = Number.NEGATIVE_INFINITY, + POSITIVE_INFINITY = Number.POSITIVE_INFINITY; + + /** Used as references for the maximum length and index of an array. */ + var MAX_ARRAY_LENGTH = 4294967295, + MAX_ARRAY_INDEX = MAX_ARRAY_LENGTH - 1, + HALF_MAX_ARRAY_LENGTH = MAX_ARRAY_LENGTH >>> 1; + + /** + * Used as the [maximum length](http://ecma-international.org/ecma-262/6.0/#sec-number.max_safe_integer) + * of an array-like value. + */ + var MAX_SAFE_INTEGER = 9007199254740991; + + /** Used to store function metadata. */ + var metaMap = WeakMap && new WeakMap; + + /** Used to lookup unminified function names. */ + var realNames = {}; + + /*------------------------------------------------------------------------*/ + + /** + * Creates a `lodash` object which wraps `value` to enable implicit chaining. + * Methods that operate on and return arrays, collections, and functions can + * be chained together. Methods that retrieve a single value or may return a + * primitive value will automatically end the chain returning the unwrapped + * value. Explicit chaining may be enabled using `_.chain`. The execution of + * chained methods is lazy, that is, execution is deferred until `_#value` + * is implicitly or explicitly called. + * + * Lazy evaluation allows several methods to support shortcut fusion. Shortcut + * fusion is an optimization strategy which merge iteratee calls; this can help + * to avoid the creation of intermediate data structures and greatly reduce the + * number of iteratee executions. + * + * Chaining is supported in custom builds as long as the `_#value` method is + * directly or indirectly included in the build. + * + * In addition to lodash methods, wrappers have `Array` and `String` methods. + * + * The wrapper `Array` methods are: + * `concat`, `join`, `pop`, `push`, `reverse`, `shift`, `slice`, `sort`, + * `splice`, and `unshift` + * + * The wrapper `String` methods are: + * `replace` and `split` + * + * The wrapper methods that support shortcut fusion are: + * `compact`, `drop`, `dropRight`, `dropRightWhile`, `dropWhile`, `filter`, + * `first`, `initial`, `last`, `map`, `pluck`, `reject`, `rest`, `reverse`, + * `slice`, `take`, `takeRight`, `takeRightWhile`, `takeWhile`, `toArray`, + * and `where` + * + * The chainable wrapper methods are: + * `after`, `ary`, `assign`, `at`, `before`, `bind`, `bindAll`, `bindKey`, + * `callback`, `chain`, `chunk`, `commit`, `compact`, `concat`, `constant`, + * `countBy`, `create`, `curry`, `debounce`, `defaults`, `defaultsDeep`, + * `defer`, `delay`, `difference`, `drop`, `dropRight`, `dropRightWhile`, + * `dropWhile`, `fill`, `filter`, `flatten`, `flattenDeep`, `flow`, `flowRight`, + * `forEach`, `forEachRight`, `forIn`, `forInRight`, `forOwn`, `forOwnRight`, + * `functions`, `groupBy`, `indexBy`, `initial`, `intersection`, `invert`, + * `invoke`, `keys`, `keysIn`, `map`, `mapKeys`, `mapValues`, `matches`, + * `matchesProperty`, `memoize`, `merge`, `method`, `methodOf`, `mixin`, + * `modArgs`, `negate`, `omit`, `once`, `pairs`, `partial`, `partialRight`, + * `partition`, `pick`, `plant`, `pluck`, `property`, `propertyOf`, `pull`, + * `pullAt`, `push`, `range`, `rearg`, `reject`, `remove`, `rest`, `restParam`, + * `reverse`, `set`, `shuffle`, `slice`, `sort`, `sortBy`, `sortByAll`, + * `sortByOrder`, `splice`, `spread`, `take`, `takeRight`, `takeRightWhile`, + * `takeWhile`, `tap`, `throttle`, `thru`, `times`, `toArray`, `toPlainObject`, + * `transform`, `union`, `uniq`, `unshift`, `unzip`, `unzipWith`, `values`, + * `valuesIn`, `where`, `without`, `wrap`, `xor`, `zip`, `zipObject`, `zipWith` + * + * The wrapper methods that are **not** chainable by default are: + * `add`, `attempt`, `camelCase`, `capitalize`, `ceil`, `clone`, `cloneDeep`, + * `deburr`, `endsWith`, `escape`, `escapeRegExp`, `every`, `find`, `findIndex`, + * `findKey`, `findLast`, `findLastIndex`, `findLastKey`, `findWhere`, `first`, + * `floor`, `get`, `gt`, `gte`, `has`, `identity`, `includes`, `indexOf`, + * `inRange`, `isArguments`, `isArray`, `isBoolean`, `isDate`, `isElement`, + * `isEmpty`, `isEqual`, `isError`, `isFinite` `isFunction`, `isMatch`, + * `isNative`, `isNaN`, `isNull`, `isNumber`, `isObject`, `isPlainObject`, + * `isRegExp`, `isString`, `isUndefined`, `isTypedArray`, `join`, `kebabCase`, + * `last`, `lastIndexOf`, `lt`, `lte`, `max`, `min`, `noConflict`, `noop`, + * `now`, `pad`, `padLeft`, `padRight`, `parseInt`, `pop`, `random`, `reduce`, + * `reduceRight`, `repeat`, `result`, `round`, `runInContext`, `shift`, `size`, + * `snakeCase`, `some`, `sortedIndex`, `sortedLastIndex`, `startCase`, + * `startsWith`, `sum`, `template`, `trim`, `trimLeft`, `trimRight`, `trunc`, + * `unescape`, `uniqueId`, `value`, and `words` + * + * The wrapper method `sample` will return a wrapped value when `n` is provided, + * otherwise an unwrapped value is returned. + * + * @name _ + * @constructor + * @category Chain + * @param {*} value The value to wrap in a `lodash` instance. + * @returns {Object} Returns the new `lodash` wrapper instance. + * @example + * + * var wrapped = _([1, 2, 3]); + * + * // returns an unwrapped value + * wrapped.reduce(function(total, n) { + * return total + n; + * }); + * // => 6 + * + * // returns a wrapped value + * var squares = wrapped.map(function(n) { + * return n * n; + * }); + * + * _.isArray(squares); + * // => false + * + * _.isArray(squares.value()); + * // => true + */ + function lodash(value) { + if (isObjectLike(value) && !isArray(value) && !(value instanceof LazyWrapper)) { + if (value instanceof LodashWrapper) { + return value; + } + if (hasOwnProperty.call(value, '__chain__') && hasOwnProperty.call(value, '__wrapped__')) { + return wrapperClone(value); + } + } + return new LodashWrapper(value); + } + + /** + * The function whose prototype all chaining wrappers inherit from. + * + * @private + */ + function baseLodash() { + // No operation performed. + } + + /** + * The base constructor for creating `lodash` wrapper objects. + * + * @private + * @param {*} value The value to wrap. + * @param {boolean} [chainAll] Enable chaining for all wrapper methods. + * @param {Array} [actions=[]] Actions to peform to resolve the unwrapped value. + */ + function LodashWrapper(value, chainAll, actions) { + this.__wrapped__ = value; + this.__actions__ = actions || []; + this.__chain__ = !!chainAll; + } + + /** + * An object environment feature flags. + * + * @static + * @memberOf _ + * @type Object + */ + var support = lodash.support = {}; + + /** + * By default, the template delimiters used by lodash are like those in + * embedded Ruby (ERB). Change the following template settings to use + * alternative delimiters. + * + * @static + * @memberOf _ + * @type Object + */ + lodash.templateSettings = { + + /** + * Used to detect `data` property values to be HTML-escaped. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'escape': reEscape, + + /** + * Used to detect code to be evaluated. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'evaluate': reEvaluate, + + /** + * Used to detect `data` property values to inject. + * + * @memberOf _.templateSettings + * @type RegExp + */ + 'interpolate': reInterpolate, + + /** + * Used to reference the data object in the template text. + * + * @memberOf _.templateSettings + * @type string + */ + 'variable': '', + + /** + * Used to import variables into the compiled template. + * + * @memberOf _.templateSettings + * @type Object + */ + 'imports': { + + /** + * A reference to the `lodash` function. + * + * @memberOf _.templateSettings.imports + * @type Function + */ + '_': lodash + } + }; + + /*------------------------------------------------------------------------*/ + + /** + * Creates a lazy wrapper object which wraps `value` to enable lazy evaluation. + * + * @private + * @param {*} value The value to wrap. + */ + function LazyWrapper(value) { + this.__wrapped__ = value; + this.__actions__ = []; + this.__dir__ = 1; + this.__filtered__ = false; + this.__iteratees__ = []; + this.__takeCount__ = POSITIVE_INFINITY; + this.__views__ = []; + } + + /** + * Creates a clone of the lazy wrapper object. + * + * @private + * @name clone + * @memberOf LazyWrapper + * @returns {Object} Returns the cloned `LazyWrapper` object. + */ + function lazyClone() { + var result = new LazyWrapper(this.__wrapped__); + result.__actions__ = arrayCopy(this.__actions__); + result.__dir__ = this.__dir__; + result.__filtered__ = this.__filtered__; + result.__iteratees__ = arrayCopy(this.__iteratees__); + result.__takeCount__ = this.__takeCount__; + result.__views__ = arrayCopy(this.__views__); + return result; + } + + /** + * Reverses the direction of lazy iteration. + * + * @private + * @name reverse + * @memberOf LazyWrapper + * @returns {Object} Returns the new reversed `LazyWrapper` object. + */ + function lazyReverse() { + if (this.__filtered__) { + var result = new LazyWrapper(this); + result.__dir__ = -1; + result.__filtered__ = true; + } else { + result = this.clone(); + result.__dir__ *= -1; + } + return result; + } + + /** + * Extracts the unwrapped value from its lazy wrapper. + * + * @private + * @name value + * @memberOf LazyWrapper + * @returns {*} Returns the unwrapped value. + */ + function lazyValue() { + var array = this.__wrapped__.value(), + dir = this.__dir__, + isArr = isArray(array), + isRight = dir < 0, + arrLength = isArr ? array.length : 0, + view = getView(0, arrLength, this.__views__), + start = view.start, + end = view.end, + length = end - start, + index = isRight ? end : (start - 1), + iteratees = this.__iteratees__, + iterLength = iteratees.length, + resIndex = 0, + takeCount = nativeMin(length, this.__takeCount__); + + if (!isArr || arrLength < LARGE_ARRAY_SIZE || (arrLength == length && takeCount == length)) { + return baseWrapperValue((isRight && isArr) ? array.reverse() : array, this.__actions__); + } + var result = []; + + outer: + while (length-- && resIndex < takeCount) { + index += dir; + + var iterIndex = -1, + value = array[index]; + + while (++iterIndex < iterLength) { + var data = iteratees[iterIndex], + iteratee = data.iteratee, + type = data.type, + computed = iteratee(value); + + if (type == LAZY_MAP_FLAG) { + value = computed; + } else if (!computed) { + if (type == LAZY_FILTER_FLAG) { + continue outer; + } else { + break outer; + } + } + } + result[resIndex++] = value; + } + return result; + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a cache object to store key/value pairs. + * + * @private + * @static + * @name Cache + * @memberOf _.memoize + */ + function MapCache() { + this.__data__ = {}; + } + + /** + * Removes `key` and its value from the cache. + * + * @private + * @name delete + * @memberOf _.memoize.Cache + * @param {string} key The key of the value to remove. + * @returns {boolean} Returns `true` if the entry was removed successfully, else `false`. + */ + function mapDelete(key) { + return this.has(key) && delete this.__data__[key]; + } + + /** + * Gets the cached value for `key`. + * + * @private + * @name get + * @memberOf _.memoize.Cache + * @param {string} key The key of the value to get. + * @returns {*} Returns the cached value. + */ + function mapGet(key) { + return key == '__proto__' ? undefined : this.__data__[key]; + } + + /** + * Checks if a cached value for `key` exists. + * + * @private + * @name has + * @memberOf _.memoize.Cache + * @param {string} key The key of the entry to check. + * @returns {boolean} Returns `true` if an entry for `key` exists, else `false`. + */ + function mapHas(key) { + return key != '__proto__' && hasOwnProperty.call(this.__data__, key); + } + + /** + * Sets `value` to `key` of the cache. + * + * @private + * @name set + * @memberOf _.memoize.Cache + * @param {string} key The key of the value to cache. + * @param {*} value The value to cache. + * @returns {Object} Returns the cache object. + */ + function mapSet(key, value) { + if (key != '__proto__') { + this.__data__[key] = value; + } + return this; + } + + /*------------------------------------------------------------------------*/ + + /** + * + * Creates a cache object to store unique values. + * + * @private + * @param {Array} [values] The values to cache. + */ + function SetCache(values) { + var length = values ? values.length : 0; + + this.data = { 'hash': nativeCreate(null), 'set': new Set }; + while (length--) { + this.push(values[length]); + } + } + + /** + * Checks if `value` is in `cache` mimicking the return signature of + * `_.indexOf` by returning `0` if the value is found, else `-1`. + * + * @private + * @param {Object} cache The cache to search. + * @param {*} value The value to search for. + * @returns {number} Returns `0` if `value` is found, else `-1`. + */ + function cacheIndexOf(cache, value) { + var data = cache.data, + result = (typeof value == 'string' || isObject(value)) ? data.set.has(value) : data.hash[value]; + + return result ? 0 : -1; + } + + /** + * Adds `value` to the cache. + * + * @private + * @name push + * @memberOf SetCache + * @param {*} value The value to cache. + */ + function cachePush(value) { + var data = this.data; + if (typeof value == 'string' || isObject(value)) { + data.set.add(value); + } else { + data.hash[value] = true; + } + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a new array joining `array` with `other`. + * + * @private + * @param {Array} array The array to join. + * @param {Array} other The other array to join. + * @returns {Array} Returns the new concatenated array. + */ + function arrayConcat(array, other) { + var index = -1, + length = array.length, + othIndex = -1, + othLength = other.length, + result = Array(length + othLength); + + while (++index < length) { + result[index] = array[index]; + } + while (++othIndex < othLength) { + result[index++] = other[othIndex]; + } + return result; + } + + /** + * Copies the values of `source` to `array`. + * + * @private + * @param {Array} source The array to copy values from. + * @param {Array} [array=[]] The array to copy values to. + * @returns {Array} Returns `array`. + */ + function arrayCopy(source, array) { + var index = -1, + length = source.length; + + array || (array = Array(length)); + while (++index < length) { + array[index] = source[index]; + } + return array; + } + + /** + * A specialized version of `_.forEach` for arrays without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns `array`. + */ + function arrayEach(array, iteratee) { + var index = -1, + length = array.length; + + while (++index < length) { + if (iteratee(array[index], index, array) === false) { + break; + } + } + return array; + } + + /** + * A specialized version of `_.forEachRight` for arrays without support for + * callback shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns `array`. + */ + function arrayEachRight(array, iteratee) { + var length = array.length; + + while (length--) { + if (iteratee(array[length], length, array) === false) { + break; + } + } + return array; + } + + /** + * A specialized version of `_.every` for arrays without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if all elements pass the predicate check, + * else `false`. + */ + function arrayEvery(array, predicate) { + var index = -1, + length = array.length; + + while (++index < length) { + if (!predicate(array[index], index, array)) { + return false; + } + } + return true; + } + + /** + * A specialized version of `baseExtremum` for arrays which invokes `iteratee` + * with one argument: (value). + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {Function} comparator The function used to compare values. + * @param {*} exValue The initial extremum value. + * @returns {*} Returns the extremum value. + */ + function arrayExtremum(array, iteratee, comparator, exValue) { + var index = -1, + length = array.length, + computed = exValue, + result = computed; + + while (++index < length) { + var value = array[index], + current = +iteratee(value); + + if (comparator(current, computed)) { + computed = current; + result = value; + } + } + return result; + } + + /** + * A specialized version of `_.filter` for arrays without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {Array} Returns the new filtered array. + */ + function arrayFilter(array, predicate) { + var index = -1, + length = array.length, + resIndex = -1, + result = []; + + while (++index < length) { + var value = array[index]; + if (predicate(value, index, array)) { + result[++resIndex] = value; + } + } + return result; + } + + /** + * A specialized version of `_.map` for arrays without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns the new mapped array. + */ + function arrayMap(array, iteratee) { + var index = -1, + length = array.length, + result = Array(length); + + while (++index < length) { + result[index] = iteratee(array[index], index, array); + } + return result; + } + + /** + * Appends the elements of `values` to `array`. + * + * @private + * @param {Array} array The array to modify. + * @param {Array} values The values to append. + * @returns {Array} Returns `array`. + */ + function arrayPush(array, values) { + var index = -1, + length = values.length, + offset = array.length; + + while (++index < length) { + array[offset + index] = values[index]; + } + return array; + } + + /** + * A specialized version of `_.reduce` for arrays without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {boolean} [initFromArray] Specify using the first element of `array` + * as the initial value. + * @returns {*} Returns the accumulated value. + */ + function arrayReduce(array, iteratee, accumulator, initFromArray) { + var index = -1, + length = array.length; + + if (initFromArray && length) { + accumulator = array[++index]; + } + while (++index < length) { + accumulator = iteratee(accumulator, array[index], index, array); + } + return accumulator; + } + + /** + * A specialized version of `_.reduceRight` for arrays without support for + * callback shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {boolean} [initFromArray] Specify using the last element of `array` + * as the initial value. + * @returns {*} Returns the accumulated value. + */ + function arrayReduceRight(array, iteratee, accumulator, initFromArray) { + var length = array.length; + if (initFromArray && length) { + accumulator = array[--length]; + } + while (length--) { + accumulator = iteratee(accumulator, array[length], length, array); + } + return accumulator; + } + + /** + * A specialized version of `_.some` for arrays without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if any element passes the predicate check, + * else `false`. + */ + function arraySome(array, predicate) { + var index = -1, + length = array.length; + + while (++index < length) { + if (predicate(array[index], index, array)) { + return true; + } + } + return false; + } + + /** + * A specialized version of `_.sum` for arrays without support for callback + * shorthands and `this` binding.. + * + * @private + * @param {Array} array The array to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {number} Returns the sum. + */ + function arraySum(array, iteratee) { + var length = array.length, + result = 0; + + while (length--) { + result += +iteratee(array[length]) || 0; + } + return result; + } + + /** + * Used by `_.defaults` to customize its `_.assign` use. + * + * @private + * @param {*} objectValue The destination object property value. + * @param {*} sourceValue The source object property value. + * @returns {*} Returns the value to assign to the destination object. + */ + function assignDefaults(objectValue, sourceValue) { + return objectValue === undefined ? sourceValue : objectValue; + } + + /** + * Used by `_.template` to customize its `_.assign` use. + * + * **Note:** This function is like `assignDefaults` except that it ignores + * inherited property values when checking if a property is `undefined`. + * + * @private + * @param {*} objectValue The destination object property value. + * @param {*} sourceValue The source object property value. + * @param {string} key The key associated with the object and source values. + * @param {Object} object The destination object. + * @returns {*} Returns the value to assign to the destination object. + */ + function assignOwnDefaults(objectValue, sourceValue, key, object) { + return (objectValue === undefined || !hasOwnProperty.call(object, key)) + ? sourceValue + : objectValue; + } + + /** + * A specialized version of `_.assign` for customizing assigned values without + * support for argument juggling, multiple sources, and `this` binding `customizer` + * functions. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {Function} customizer The function to customize assigned values. + * @returns {Object} Returns `object`. + */ + function assignWith(object, source, customizer) { + var index = -1, + props = keys(source), + length = props.length; + + while (++index < length) { + var key = props[index], + value = object[key], + result = customizer(value, source[key], key, object, source); + + if ((result === result ? (result !== value) : (value === value)) || + (value === undefined && !(key in object))) { + object[key] = result; + } + } + return object; + } + + /** + * The base implementation of `_.assign` without support for argument juggling, + * multiple sources, and `customizer` functions. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @returns {Object} Returns `object`. + */ + function baseAssign(object, source) { + return source == null + ? object + : baseCopy(source, keys(source), object); + } + + /** + * The base implementation of `_.at` without support for string collections + * and individual key arguments. + * + * @private + * @param {Array|Object} collection The collection to iterate over. + * @param {number[]|string[]} props The property names or indexes of elements to pick. + * @returns {Array} Returns the new array of picked elements. + */ + function baseAt(collection, props) { + var index = -1, + isNil = collection == null, + isArr = !isNil && isArrayLike(collection), + length = isArr ? collection.length : 0, + propsLength = props.length, + result = Array(propsLength); + + while(++index < propsLength) { + var key = props[index]; + if (isArr) { + result[index] = isIndex(key, length) ? collection[key] : undefined; + } else { + result[index] = isNil ? undefined : collection[key]; + } + } + return result; + } + + /** + * Copies properties of `source` to `object`. + * + * @private + * @param {Object} source The object to copy properties from. + * @param {Array} props The property names to copy. + * @param {Object} [object={}] The object to copy properties to. + * @returns {Object} Returns `object`. + */ + function baseCopy(source, props, object) { + object || (object = {}); + + var index = -1, + length = props.length; + + while (++index < length) { + var key = props[index]; + object[key] = source[key]; + } + return object; + } + + /** + * The base implementation of `_.callback` which supports specifying the + * number of arguments to provide to `func`. + * + * @private + * @param {*} [func=_.identity] The value to convert to a callback. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {number} [argCount] The number of arguments to provide to `func`. + * @returns {Function} Returns the callback. + */ + function baseCallback(func, thisArg, argCount) { + var type = typeof func; + if (type == 'function') { + return thisArg === undefined + ? func + : bindCallback(func, thisArg, argCount); + } + if (func == null) { + return identity; + } + if (type == 'object') { + return baseMatches(func); + } + return thisArg === undefined + ? property(func) + : baseMatchesProperty(func, thisArg); + } + + /** + * The base implementation of `_.clone` without support for argument juggling + * and `this` binding `customizer` functions. + * + * @private + * @param {*} value The value to clone. + * @param {boolean} [isDeep] Specify a deep clone. + * @param {Function} [customizer] The function to customize cloning values. + * @param {string} [key] The key of `value`. + * @param {Object} [object] The object `value` belongs to. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates clones with source counterparts. + * @returns {*} Returns the cloned value. + */ + function baseClone(value, isDeep, customizer, key, object, stackA, stackB) { + var result; + if (customizer) { + result = object ? customizer(value, key, object) : customizer(value); + } + if (result !== undefined) { + return result; + } + if (!isObject(value)) { + return value; + } + var isArr = isArray(value); + if (isArr) { + result = initCloneArray(value); + if (!isDeep) { + return arrayCopy(value, result); + } + } else { + var tag = objToString.call(value), + isFunc = tag == funcTag; + + if (tag == objectTag || tag == argsTag || (isFunc && !object)) { + result = initCloneObject(isFunc ? {} : value); + if (!isDeep) { + return baseAssign(result, value); + } + } else { + return cloneableTags[tag] + ? initCloneByTag(value, tag, isDeep) + : (object ? value : {}); + } + } + // Check for circular references and return its corresponding clone. + stackA || (stackA = []); + stackB || (stackB = []); + + var length = stackA.length; + while (length--) { + if (stackA[length] == value) { + return stackB[length]; + } + } + // Add the source value to the stack of traversed objects and associate it with its clone. + stackA.push(value); + stackB.push(result); + + // Recursively populate clone (susceptible to call stack limits). + (isArr ? arrayEach : baseForOwn)(value, function(subValue, key) { + result[key] = baseClone(subValue, isDeep, customizer, key, value, stackA, stackB); + }); + return result; + } + + /** + * The base implementation of `_.create` without support for assigning + * properties to the created object. + * + * @private + * @param {Object} prototype The object to inherit from. + * @returns {Object} Returns the new object. + */ + var baseCreate = (function() { + function object() {} + return function(prototype) { + if (isObject(prototype)) { + object.prototype = prototype; + var result = new object; + object.prototype = undefined; + } + return result || {}; + }; + }()); + + /** + * The base implementation of `_.delay` and `_.defer` which accepts an index + * of where to slice the arguments to provide to `func`. + * + * @private + * @param {Function} func The function to delay. + * @param {number} wait The number of milliseconds to delay invocation. + * @param {Object} args The arguments provide to `func`. + * @returns {number} Returns the timer id. + */ + function baseDelay(func, wait, args) { + if (typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + return setTimeout(function() { func.apply(undefined, args); }, wait); + } + + /** + * The base implementation of `_.difference` which accepts a single array + * of values to exclude. + * + * @private + * @param {Array} array The array to inspect. + * @param {Array} values The values to exclude. + * @returns {Array} Returns the new array of filtered values. + */ + function baseDifference(array, values) { + var length = array ? array.length : 0, + result = []; + + if (!length) { + return result; + } + var index = -1, + indexOf = getIndexOf(), + isCommon = indexOf == baseIndexOf, + cache = (isCommon && values.length >= LARGE_ARRAY_SIZE) ? createCache(values) : null, + valuesLength = values.length; + + if (cache) { + indexOf = cacheIndexOf; + isCommon = false; + values = cache; + } + outer: + while (++index < length) { + var value = array[index]; + + if (isCommon && value === value) { + var valuesIndex = valuesLength; + while (valuesIndex--) { + if (values[valuesIndex] === value) { + continue outer; + } + } + result.push(value); + } + else if (indexOf(values, value, 0) < 0) { + result.push(value); + } + } + return result; + } + + /** + * The base implementation of `_.forEach` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array|Object|string} Returns `collection`. + */ + var baseEach = createBaseEach(baseForOwn); + + /** + * The base implementation of `_.forEachRight` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array|Object|string} Returns `collection`. + */ + var baseEachRight = createBaseEach(baseForOwnRight, true); + + /** + * The base implementation of `_.every` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if all elements pass the predicate check, + * else `false` + */ + function baseEvery(collection, predicate) { + var result = true; + baseEach(collection, function(value, index, collection) { + result = !!predicate(value, index, collection); + return result; + }); + return result; + } + + /** + * Gets the extremum value of `collection` invoking `iteratee` for each value + * in `collection` to generate the criterion by which the value is ranked. + * The `iteratee` is invoked with three arguments: (value, index|key, collection). + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {Function} comparator The function used to compare values. + * @param {*} exValue The initial extremum value. + * @returns {*} Returns the extremum value. + */ + function baseExtremum(collection, iteratee, comparator, exValue) { + var computed = exValue, + result = computed; + + baseEach(collection, function(value, index, collection) { + var current = +iteratee(value, index, collection); + if (comparator(current, computed) || (current === exValue && current === result)) { + computed = current; + result = value; + } + }); + return result; + } + + /** + * The base implementation of `_.fill` without an iteratee call guard. + * + * @private + * @param {Array} array The array to fill. + * @param {*} value The value to fill `array` with. + * @param {number} [start=0] The start position. + * @param {number} [end=array.length] The end position. + * @returns {Array} Returns `array`. + */ + function baseFill(array, value, start, end) { + var length = array.length; + + start = start == null ? 0 : (+start || 0); + if (start < 0) { + start = -start > length ? 0 : (length + start); + } + end = (end === undefined || end > length) ? length : (+end || 0); + if (end < 0) { + end += length; + } + length = start > end ? 0 : (end >>> 0); + start >>>= 0; + + while (start < length) { + array[start++] = value; + } + return array; + } + + /** + * The base implementation of `_.filter` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {Array} Returns the new filtered array. + */ + function baseFilter(collection, predicate) { + var result = []; + baseEach(collection, function(value, index, collection) { + if (predicate(value, index, collection)) { + result.push(value); + } + }); + return result; + } + + /** + * The base implementation of `_.find`, `_.findLast`, `_.findKey`, and `_.findLastKey`, + * without support for callback shorthands and `this` binding, which iterates + * over `collection` using the provided `eachFunc`. + * + * @private + * @param {Array|Object|string} collection The collection to search. + * @param {Function} predicate The function invoked per iteration. + * @param {Function} eachFunc The function to iterate over `collection`. + * @param {boolean} [retKey] Specify returning the key of the found element + * instead of the element itself. + * @returns {*} Returns the found element or its key, else `undefined`. + */ + function baseFind(collection, predicate, eachFunc, retKey) { + var result; + eachFunc(collection, function(value, key, collection) { + if (predicate(value, key, collection)) { + result = retKey ? key : value; + return false; + } + }); + return result; + } + + /** + * The base implementation of `_.flatten` with added support for restricting + * flattening and specifying the start index. + * + * @private + * @param {Array} array The array to flatten. + * @param {boolean} [isDeep] Specify a deep flatten. + * @param {boolean} [isStrict] Restrict flattening to arrays-like objects. + * @param {Array} [result=[]] The initial result value. + * @returns {Array} Returns the new flattened array. + */ + function baseFlatten(array, isDeep, isStrict, result) { + result || (result = []); + + var index = -1, + length = array.length; + + while (++index < length) { + var value = array[index]; + if (isObjectLike(value) && isArrayLike(value) && + (isStrict || isArray(value) || isArguments(value))) { + if (isDeep) { + // Recursively flatten arrays (susceptible to call stack limits). + baseFlatten(value, isDeep, isStrict, result); + } else { + arrayPush(result, value); + } + } else if (!isStrict) { + result[result.length] = value; + } + } + return result; + } + + /** + * The base implementation of `baseForIn` and `baseForOwn` which iterates + * over `object` properties returned by `keysFunc` invoking `iteratee` for + * each property. Iteratee functions may exit iteration early by explicitly + * returning `false`. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {Function} keysFunc The function to get the keys of `object`. + * @returns {Object} Returns `object`. + */ + var baseFor = createBaseFor(); + + /** + * This function is like `baseFor` except that it iterates over properties + * in the opposite order. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {Function} keysFunc The function to get the keys of `object`. + * @returns {Object} Returns `object`. + */ + var baseForRight = createBaseFor(true); + + /** + * The base implementation of `_.forIn` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Object} Returns `object`. + */ + function baseForIn(object, iteratee) { + return baseFor(object, iteratee, keysIn); + } + + /** + * The base implementation of `_.forOwn` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Object} Returns `object`. + */ + function baseForOwn(object, iteratee) { + return baseFor(object, iteratee, keys); + } + + /** + * The base implementation of `_.forOwnRight` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Object} Returns `object`. + */ + function baseForOwnRight(object, iteratee) { + return baseForRight(object, iteratee, keys); + } + + /** + * The base implementation of `_.functions` which creates an array of + * `object` function property names filtered from those provided. + * + * @private + * @param {Object} object The object to inspect. + * @param {Array} props The property names to filter. + * @returns {Array} Returns the new array of filtered property names. + */ + function baseFunctions(object, props) { + var index = -1, + length = props.length, + resIndex = -1, + result = []; + + while (++index < length) { + var key = props[index]; + if (isFunction(object[key])) { + result[++resIndex] = key; + } + } + return result; + } + + /** + * The base implementation of `get` without support for string paths + * and default values. + * + * @private + * @param {Object} object The object to query. + * @param {Array} path The path of the property to get. + * @param {string} [pathKey] The key representation of path. + * @returns {*} Returns the resolved value. + */ + function baseGet(object, path, pathKey) { + if (object == null) { + return; + } + if (pathKey !== undefined && pathKey in toObject(object)) { + path = [pathKey]; + } + var index = 0, + length = path.length; + + while (object != null && index < length) { + object = object[path[index++]]; + } + return (index && index == length) ? object : undefined; + } + + /** + * The base implementation of `_.isEqual` without support for `this` binding + * `customizer` functions. + * + * @private + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @param {Function} [customizer] The function to customize comparing values. + * @param {boolean} [isLoose] Specify performing partial comparisons. + * @param {Array} [stackA] Tracks traversed `value` objects. + * @param {Array} [stackB] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + */ + function baseIsEqual(value, other, customizer, isLoose, stackA, stackB) { + if (value === other) { + return true; + } + if (value == null || other == null || (!isObject(value) && !isObjectLike(other))) { + return value !== value && other !== other; + } + return baseIsEqualDeep(value, other, baseIsEqual, customizer, isLoose, stackA, stackB); + } + + /** + * A specialized version of `baseIsEqual` for arrays and objects which performs + * deep comparisons and tracks traversed objects enabling objects with circular + * references to be compared. + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @param {Function} equalFunc The function to determine equivalents of values. + * @param {Function} [customizer] The function to customize comparing objects. + * @param {boolean} [isLoose] Specify performing partial comparisons. + * @param {Array} [stackA=[]] Tracks traversed `value` objects. + * @param {Array} [stackB=[]] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function baseIsEqualDeep(object, other, equalFunc, customizer, isLoose, stackA, stackB) { + var objIsArr = isArray(object), + othIsArr = isArray(other), + objTag = arrayTag, + othTag = arrayTag; + + if (!objIsArr) { + objTag = objToString.call(object); + if (objTag == argsTag) { + objTag = objectTag; + } else if (objTag != objectTag) { + objIsArr = isTypedArray(object); + } + } + if (!othIsArr) { + othTag = objToString.call(other); + if (othTag == argsTag) { + othTag = objectTag; + } else if (othTag != objectTag) { + othIsArr = isTypedArray(other); + } + } + var objIsObj = objTag == objectTag, + othIsObj = othTag == objectTag, + isSameTag = objTag == othTag; + + if (isSameTag && !(objIsArr || objIsObj)) { + return equalByTag(object, other, objTag); + } + if (!isLoose) { + var objIsWrapped = objIsObj && hasOwnProperty.call(object, '__wrapped__'), + othIsWrapped = othIsObj && hasOwnProperty.call(other, '__wrapped__'); + + if (objIsWrapped || othIsWrapped) { + return equalFunc(objIsWrapped ? object.value() : object, othIsWrapped ? other.value() : other, customizer, isLoose, stackA, stackB); + } + } + if (!isSameTag) { + return false; + } + // Assume cyclic values are equal. + // For more information on detecting circular references see https://es5.github.io/#JO. + stackA || (stackA = []); + stackB || (stackB = []); + + var length = stackA.length; + while (length--) { + if (stackA[length] == object) { + return stackB[length] == other; + } + } + // Add `object` and `other` to the stack of traversed objects. + stackA.push(object); + stackB.push(other); + + var result = (objIsArr ? equalArrays : equalObjects)(object, other, equalFunc, customizer, isLoose, stackA, stackB); + + stackA.pop(); + stackB.pop(); + + return result; + } + + /** + * The base implementation of `_.isMatch` without support for callback + * shorthands and `this` binding. + * + * @private + * @param {Object} object The object to inspect. + * @param {Array} matchData The propery names, values, and compare flags to match. + * @param {Function} [customizer] The function to customize comparing objects. + * @returns {boolean} Returns `true` if `object` is a match, else `false`. + */ + function baseIsMatch(object, matchData, customizer) { + var index = matchData.length, + length = index, + noCustomizer = !customizer; + + if (object == null) { + return !length; + } + object = toObject(object); + while (index--) { + var data = matchData[index]; + if ((noCustomizer && data[2]) + ? data[1] !== object[data[0]] + : !(data[0] in object) + ) { + return false; + } + } + while (++index < length) { + data = matchData[index]; + var key = data[0], + objValue = object[key], + srcValue = data[1]; + + if (noCustomizer && data[2]) { + if (objValue === undefined && !(key in object)) { + return false; + } + } else { + var result = customizer ? customizer(objValue, srcValue, key) : undefined; + if (!(result === undefined ? baseIsEqual(srcValue, objValue, customizer, true) : result)) { + return false; + } + } + } + return true; + } + + /** + * The base implementation of `_.map` without support for callback shorthands + * and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {Array} Returns the new mapped array. + */ + function baseMap(collection, iteratee) { + var index = -1, + result = isArrayLike(collection) ? Array(collection.length) : []; + + baseEach(collection, function(value, key, collection) { + result[++index] = iteratee(value, key, collection); + }); + return result; + } + + /** + * The base implementation of `_.matches` which does not clone `source`. + * + * @private + * @param {Object} source The object of property values to match. + * @returns {Function} Returns the new function. + */ + function baseMatches(source) { + var matchData = getMatchData(source); + if (matchData.length == 1 && matchData[0][2]) { + var key = matchData[0][0], + value = matchData[0][1]; + + return function(object) { + if (object == null) { + return false; + } + return object[key] === value && (value !== undefined || (key in toObject(object))); + }; + } + return function(object) { + return baseIsMatch(object, matchData); + }; + } + + /** + * The base implementation of `_.matchesProperty` which does not clone `srcValue`. + * + * @private + * @param {string} path The path of the property to get. + * @param {*} srcValue The value to compare. + * @returns {Function} Returns the new function. + */ + function baseMatchesProperty(path, srcValue) { + var isArr = isArray(path), + isCommon = isKey(path) && isStrictComparable(srcValue), + pathKey = (path + ''); + + path = toPath(path); + return function(object) { + if (object == null) { + return false; + } + var key = pathKey; + object = toObject(object); + if ((isArr || !isCommon) && !(key in object)) { + object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1)); + if (object == null) { + return false; + } + key = last(path); + object = toObject(object); + } + return object[key] === srcValue + ? (srcValue !== undefined || (key in object)) + : baseIsEqual(srcValue, object[key], undefined, true); + }; + } + + /** + * The base implementation of `_.merge` without support for argument juggling, + * multiple sources, and `this` binding `customizer` functions. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {Function} [customizer] The function to customize merged values. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates values with source counterparts. + * @returns {Object} Returns `object`. + */ + function baseMerge(object, source, customizer, stackA, stackB) { + if (!isObject(object)) { + return object; + } + var isSrcArr = isArrayLike(source) && (isArray(source) || isTypedArray(source)), + props = isSrcArr ? undefined : keys(source); + + arrayEach(props || source, function(srcValue, key) { + if (props) { + key = srcValue; + srcValue = source[key]; + } + if (isObjectLike(srcValue)) { + stackA || (stackA = []); + stackB || (stackB = []); + baseMergeDeep(object, source, key, baseMerge, customizer, stackA, stackB); + } + else { + var value = object[key], + result = customizer ? customizer(value, srcValue, key, object, source) : undefined, + isCommon = result === undefined; + + if (isCommon) { + result = srcValue; + } + if ((result !== undefined || (isSrcArr && !(key in object))) && + (isCommon || (result === result ? (result !== value) : (value === value)))) { + object[key] = result; + } + } + }); + return object; + } + + /** + * A specialized version of `baseMerge` for arrays and objects which performs + * deep merges and tracks traversed objects enabling objects with circular + * references to be merged. + * + * @private + * @param {Object} object The destination object. + * @param {Object} source The source object. + * @param {string} key The key of the value to merge. + * @param {Function} mergeFunc The function to merge values. + * @param {Function} [customizer] The function to customize merged values. + * @param {Array} [stackA=[]] Tracks traversed source objects. + * @param {Array} [stackB=[]] Associates values with source counterparts. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function baseMergeDeep(object, source, key, mergeFunc, customizer, stackA, stackB) { + var length = stackA.length, + srcValue = source[key]; + + while (length--) { + if (stackA[length] == srcValue) { + object[key] = stackB[length]; + return; + } + } + var value = object[key], + result = customizer ? customizer(value, srcValue, key, object, source) : undefined, + isCommon = result === undefined; + + if (isCommon) { + result = srcValue; + if (isArrayLike(srcValue) && (isArray(srcValue) || isTypedArray(srcValue))) { + result = isArray(value) + ? value + : (isArrayLike(value) ? arrayCopy(value) : []); + } + else if (isPlainObject(srcValue) || isArguments(srcValue)) { + result = isArguments(value) + ? toPlainObject(value) + : (isPlainObject(value) ? value : {}); + } + else { + isCommon = false; + } + } + // Add the source value to the stack of traversed objects and associate + // it with its merged value. + stackA.push(srcValue); + stackB.push(result); + + if (isCommon) { + // Recursively merge objects and arrays (susceptible to call stack limits). + object[key] = mergeFunc(result, srcValue, customizer, stackA, stackB); + } else if (result === result ? (result !== value) : (value === value)) { + object[key] = result; + } + } + + /** + * The base implementation of `_.property` without support for deep paths. + * + * @private + * @param {string} key The key of the property to get. + * @returns {Function} Returns the new function. + */ + function baseProperty(key) { + return function(object) { + return object == null ? undefined : object[key]; + }; + } + + /** + * A specialized version of `baseProperty` which supports deep paths. + * + * @private + * @param {Array|string} path The path of the property to get. + * @returns {Function} Returns the new function. + */ + function basePropertyDeep(path) { + var pathKey = (path + ''); + path = toPath(path); + return function(object) { + return baseGet(object, path, pathKey); + }; + } + + /** + * The base implementation of `_.pullAt` without support for individual + * index arguments and capturing the removed elements. + * + * @private + * @param {Array} array The array to modify. + * @param {number[]} indexes The indexes of elements to remove. + * @returns {Array} Returns `array`. + */ + function basePullAt(array, indexes) { + var length = array ? indexes.length : 0; + while (length--) { + var index = indexes[length]; + if (index != previous && isIndex(index)) { + var previous = index; + splice.call(array, index, 1); + } + } + return array; + } + + /** + * The base implementation of `_.random` without support for argument juggling + * and returning floating-point numbers. + * + * @private + * @param {number} min The minimum possible value. + * @param {number} max The maximum possible value. + * @returns {number} Returns the random number. + */ + function baseRandom(min, max) { + return min + nativeFloor(nativeRandom() * (max - min + 1)); + } + + /** + * The base implementation of `_.reduce` and `_.reduceRight` without support + * for callback shorthands and `this` binding, which iterates over `collection` + * using the provided `eachFunc`. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @param {*} accumulator The initial value. + * @param {boolean} initFromCollection Specify using the first or last element + * of `collection` as the initial value. + * @param {Function} eachFunc The function to iterate over `collection`. + * @returns {*} Returns the accumulated value. + */ + function baseReduce(collection, iteratee, accumulator, initFromCollection, eachFunc) { + eachFunc(collection, function(value, index, collection) { + accumulator = initFromCollection + ? (initFromCollection = false, value) + : iteratee(accumulator, value, index, collection); + }); + return accumulator; + } + + /** + * The base implementation of `setData` without support for hot loop detection. + * + * @private + * @param {Function} func The function to associate metadata with. + * @param {*} data The metadata. + * @returns {Function} Returns `func`. + */ + var baseSetData = !metaMap ? identity : function(func, data) { + metaMap.set(func, data); + return func; + }; + + /** + * The base implementation of `_.slice` without an iteratee call guard. + * + * @private + * @param {Array} array The array to slice. + * @param {number} [start=0] The start position. + * @param {number} [end=array.length] The end position. + * @returns {Array} Returns the slice of `array`. + */ + function baseSlice(array, start, end) { + var index = -1, + length = array.length; + + start = start == null ? 0 : (+start || 0); + if (start < 0) { + start = -start > length ? 0 : (length + start); + } + end = (end === undefined || end > length) ? length : (+end || 0); + if (end < 0) { + end += length; + } + length = start > end ? 0 : ((end - start) >>> 0); + start >>>= 0; + + var result = Array(length); + while (++index < length) { + result[index] = array[index + start]; + } + return result; + } + + /** + * The base implementation of `_.some` without support for callback shorthands + * and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} predicate The function invoked per iteration. + * @returns {boolean} Returns `true` if any element passes the predicate check, + * else `false`. + */ + function baseSome(collection, predicate) { + var result; + + baseEach(collection, function(value, index, collection) { + result = predicate(value, index, collection); + return !result; + }); + return !!result; + } + + /** + * The base implementation of `_.sortBy` which uses `comparer` to define + * the sort order of `array` and replaces criteria objects with their + * corresponding values. + * + * @private + * @param {Array} array The array to sort. + * @param {Function} comparer The function to define sort order. + * @returns {Array} Returns `array`. + */ + function baseSortBy(array, comparer) { + var length = array.length; + + array.sort(comparer); + while (length--) { + array[length] = array[length].value; + } + return array; + } + + /** + * The base implementation of `_.sortByOrder` without param guards. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function[]|Object[]|string[]} iteratees The iteratees to sort by. + * @param {boolean[]} orders The sort orders of `iteratees`. + * @returns {Array} Returns the new sorted array. + */ + function baseSortByOrder(collection, iteratees, orders) { + var callback = getCallback(), + index = -1; + + iteratees = arrayMap(iteratees, function(iteratee) { return callback(iteratee); }); + + var result = baseMap(collection, function(value) { + var criteria = arrayMap(iteratees, function(iteratee) { return iteratee(value); }); + return { 'criteria': criteria, 'index': ++index, 'value': value }; + }); + + return baseSortBy(result, function(object, other) { + return compareMultiple(object, other, orders); + }); + } + + /** + * The base implementation of `_.sum` without support for callback shorthands + * and `this` binding. + * + * @private + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} iteratee The function invoked per iteration. + * @returns {number} Returns the sum. + */ + function baseSum(collection, iteratee) { + var result = 0; + baseEach(collection, function(value, index, collection) { + result += +iteratee(value, index, collection) || 0; + }); + return result; + } + + /** + * The base implementation of `_.uniq` without support for callback shorthands + * and `this` binding. + * + * @private + * @param {Array} array The array to inspect. + * @param {Function} [iteratee] The function invoked per iteration. + * @returns {Array} Returns the new duplicate-value-free array. + */ + function baseUniq(array, iteratee) { + var index = -1, + indexOf = getIndexOf(), + length = array.length, + isCommon = indexOf == baseIndexOf, + isLarge = isCommon && length >= LARGE_ARRAY_SIZE, + seen = isLarge ? createCache() : null, + result = []; + + if (seen) { + indexOf = cacheIndexOf; + isCommon = false; + } else { + isLarge = false; + seen = iteratee ? [] : result; + } + outer: + while (++index < length) { + var value = array[index], + computed = iteratee ? iteratee(value, index, array) : value; + + if (isCommon && value === value) { + var seenIndex = seen.length; + while (seenIndex--) { + if (seen[seenIndex] === computed) { + continue outer; + } + } + if (iteratee) { + seen.push(computed); + } + result.push(value); + } + else if (indexOf(seen, computed, 0) < 0) { + if (iteratee || isLarge) { + seen.push(computed); + } + result.push(value); + } + } + return result; + } + + /** + * The base implementation of `_.values` and `_.valuesIn` which creates an + * array of `object` property values corresponding to the property names + * of `props`. + * + * @private + * @param {Object} object The object to query. + * @param {Array} props The property names to get values for. + * @returns {Object} Returns the array of property values. + */ + function baseValues(object, props) { + var index = -1, + length = props.length, + result = Array(length); + + while (++index < length) { + result[index] = object[props[index]]; + } + return result; + } + + /** + * The base implementation of `_.dropRightWhile`, `_.dropWhile`, `_.takeRightWhile`, + * and `_.takeWhile` without support for callback shorthands and `this` binding. + * + * @private + * @param {Array} array The array to query. + * @param {Function} predicate The function invoked per iteration. + * @param {boolean} [isDrop] Specify dropping elements instead of taking them. + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {Array} Returns the slice of `array`. + */ + function baseWhile(array, predicate, isDrop, fromRight) { + var length = array.length, + index = fromRight ? length : -1; + + while ((fromRight ? index-- : ++index < length) && predicate(array[index], index, array)) {} + return isDrop + ? baseSlice(array, (fromRight ? 0 : index), (fromRight ? index + 1 : length)) + : baseSlice(array, (fromRight ? index + 1 : 0), (fromRight ? length : index)); + } + + /** + * The base implementation of `wrapperValue` which returns the result of + * performing a sequence of actions on the unwrapped `value`, where each + * successive action is supplied the return value of the previous. + * + * @private + * @param {*} value The unwrapped value. + * @param {Array} actions Actions to peform to resolve the unwrapped value. + * @returns {*} Returns the resolved value. + */ + function baseWrapperValue(value, actions) { + var result = value; + if (result instanceof LazyWrapper) { + result = result.value(); + } + var index = -1, + length = actions.length; + + while (++index < length) { + var action = actions[index]; + result = action.func.apply(action.thisArg, arrayPush([result], action.args)); + } + return result; + } + + /** + * Performs a binary search of `array` to determine the index at which `value` + * should be inserted into `array` in order to maintain its sort order. + * + * @private + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {boolean} [retHighest] Specify returning the highest qualified index. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + */ + function binaryIndex(array, value, retHighest) { + var low = 0, + high = array ? array.length : low; + + if (typeof value == 'number' && value === value && high <= HALF_MAX_ARRAY_LENGTH) { + while (low < high) { + var mid = (low + high) >>> 1, + computed = array[mid]; + + if ((retHighest ? (computed <= value) : (computed < value)) && computed !== null) { + low = mid + 1; + } else { + high = mid; + } + } + return high; + } + return binaryIndexBy(array, value, identity, retHighest); + } + + /** + * This function is like `binaryIndex` except that it invokes `iteratee` for + * `value` and each element of `array` to compute their sort ranking. The + * iteratee is invoked with one argument; (value). + * + * @private + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {Function} iteratee The function invoked per iteration. + * @param {boolean} [retHighest] Specify returning the highest qualified index. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + */ + function binaryIndexBy(array, value, iteratee, retHighest) { + value = iteratee(value); + + var low = 0, + high = array ? array.length : 0, + valIsNaN = value !== value, + valIsNull = value === null, + valIsUndef = value === undefined; + + while (low < high) { + var mid = nativeFloor((low + high) / 2), + computed = iteratee(array[mid]), + isDef = computed !== undefined, + isReflexive = computed === computed; + + if (valIsNaN) { + var setLow = isReflexive || retHighest; + } else if (valIsNull) { + setLow = isReflexive && isDef && (retHighest || computed != null); + } else if (valIsUndef) { + setLow = isReflexive && (retHighest || isDef); + } else if (computed == null) { + setLow = false; + } else { + setLow = retHighest ? (computed <= value) : (computed < value); + } + if (setLow) { + low = mid + 1; + } else { + high = mid; + } + } + return nativeMin(high, MAX_ARRAY_INDEX); + } + + /** + * A specialized version of `baseCallback` which only supports `this` binding + * and specifying the number of arguments to provide to `func`. + * + * @private + * @param {Function} func The function to bind. + * @param {*} thisArg The `this` binding of `func`. + * @param {number} [argCount] The number of arguments to provide to `func`. + * @returns {Function} Returns the callback. + */ + function bindCallback(func, thisArg, argCount) { + if (typeof func != 'function') { + return identity; + } + if (thisArg === undefined) { + return func; + } + switch (argCount) { + case 1: return function(value) { + return func.call(thisArg, value); + }; + case 3: return function(value, index, collection) { + return func.call(thisArg, value, index, collection); + }; + case 4: return function(accumulator, value, index, collection) { + return func.call(thisArg, accumulator, value, index, collection); + }; + case 5: return function(value, other, key, object, source) { + return func.call(thisArg, value, other, key, object, source); + }; + } + return function() { + return func.apply(thisArg, arguments); + }; + } + + /** + * Creates a clone of the given array buffer. + * + * @private + * @param {ArrayBuffer} buffer The array buffer to clone. + * @returns {ArrayBuffer} Returns the cloned array buffer. + */ + function bufferClone(buffer) { + var result = new ArrayBuffer(buffer.byteLength), + view = new Uint8Array(result); + + view.set(new Uint8Array(buffer)); + return result; + } + + /** + * Creates an array that is the composition of partially applied arguments, + * placeholders, and provided arguments into a single array of arguments. + * + * @private + * @param {Array|Object} args The provided arguments. + * @param {Array} partials The arguments to prepend to those provided. + * @param {Array} holders The `partials` placeholder indexes. + * @returns {Array} Returns the new array of composed arguments. + */ + function composeArgs(args, partials, holders) { + var holdersLength = holders.length, + argsIndex = -1, + argsLength = nativeMax(args.length - holdersLength, 0), + leftIndex = -1, + leftLength = partials.length, + result = Array(leftLength + argsLength); + + while (++leftIndex < leftLength) { + result[leftIndex] = partials[leftIndex]; + } + while (++argsIndex < holdersLength) { + result[holders[argsIndex]] = args[argsIndex]; + } + while (argsLength--) { + result[leftIndex++] = args[argsIndex++]; + } + return result; + } + + /** + * This function is like `composeArgs` except that the arguments composition + * is tailored for `_.partialRight`. + * + * @private + * @param {Array|Object} args The provided arguments. + * @param {Array} partials The arguments to append to those provided. + * @param {Array} holders The `partials` placeholder indexes. + * @returns {Array} Returns the new array of composed arguments. + */ + function composeArgsRight(args, partials, holders) { + var holdersIndex = -1, + holdersLength = holders.length, + argsIndex = -1, + argsLength = nativeMax(args.length - holdersLength, 0), + rightIndex = -1, + rightLength = partials.length, + result = Array(argsLength + rightLength); + + while (++argsIndex < argsLength) { + result[argsIndex] = args[argsIndex]; + } + var offset = argsIndex; + while (++rightIndex < rightLength) { + result[offset + rightIndex] = partials[rightIndex]; + } + while (++holdersIndex < holdersLength) { + result[offset + holders[holdersIndex]] = args[argsIndex++]; + } + return result; + } + + /** + * Creates a `_.countBy`, `_.groupBy`, `_.indexBy`, or `_.partition` function. + * + * @private + * @param {Function} setter The function to set keys and values of the accumulator object. + * @param {Function} [initializer] The function to initialize the accumulator object. + * @returns {Function} Returns the new aggregator function. + */ + function createAggregator(setter, initializer) { + return function(collection, iteratee, thisArg) { + var result = initializer ? initializer() : {}; + iteratee = getCallback(iteratee, thisArg, 3); + + if (isArray(collection)) { + var index = -1, + length = collection.length; + + while (++index < length) { + var value = collection[index]; + setter(result, value, iteratee(value, index, collection), collection); + } + } else { + baseEach(collection, function(value, key, collection) { + setter(result, value, iteratee(value, key, collection), collection); + }); + } + return result; + }; + } + + /** + * Creates a `_.assign`, `_.defaults`, or `_.merge` function. + * + * @private + * @param {Function} assigner The function to assign values. + * @returns {Function} Returns the new assigner function. + */ + function createAssigner(assigner) { + return restParam(function(object, sources) { + var index = -1, + length = object == null ? 0 : sources.length, + customizer = length > 2 ? sources[length - 2] : undefined, + guard = length > 2 ? sources[2] : undefined, + thisArg = length > 1 ? sources[length - 1] : undefined; + + if (typeof customizer == 'function') { + customizer = bindCallback(customizer, thisArg, 5); + length -= 2; + } else { + customizer = typeof thisArg == 'function' ? thisArg : undefined; + length -= (customizer ? 1 : 0); + } + if (guard && isIterateeCall(sources[0], sources[1], guard)) { + customizer = length < 3 ? undefined : customizer; + length = 1; + } + while (++index < length) { + var source = sources[index]; + if (source) { + assigner(object, source, customizer); + } + } + return object; + }); + } + + /** + * Creates a `baseEach` or `baseEachRight` function. + * + * @private + * @param {Function} eachFunc The function to iterate over a collection. + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {Function} Returns the new base function. + */ + function createBaseEach(eachFunc, fromRight) { + return function(collection, iteratee) { + var length = collection ? getLength(collection) : 0; + if (!isLength(length)) { + return eachFunc(collection, iteratee); + } + var index = fromRight ? length : -1, + iterable = toObject(collection); + + while ((fromRight ? index-- : ++index < length)) { + if (iteratee(iterable[index], index, iterable) === false) { + break; + } + } + return collection; + }; + } + + /** + * Creates a base function for `_.forIn` or `_.forInRight`. + * + * @private + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {Function} Returns the new base function. + */ + function createBaseFor(fromRight) { + return function(object, iteratee, keysFunc) { + var iterable = toObject(object), + props = keysFunc(object), + length = props.length, + index = fromRight ? length : -1; + + while ((fromRight ? index-- : ++index < length)) { + var key = props[index]; + if (iteratee(iterable[key], key, iterable) === false) { + break; + } + } + return object; + }; + } + + /** + * Creates a function that wraps `func` and invokes it with the `this` + * binding of `thisArg`. + * + * @private + * @param {Function} func The function to bind. + * @param {*} [thisArg] The `this` binding of `func`. + * @returns {Function} Returns the new bound function. + */ + function createBindWrapper(func, thisArg) { + var Ctor = createCtorWrapper(func); + + function wrapper() { + var fn = (this && this !== root && this instanceof wrapper) ? Ctor : func; + return fn.apply(thisArg, arguments); + } + return wrapper; + } + + /** + * Creates a `Set` cache object to optimize linear searches of large arrays. + * + * @private + * @param {Array} [values] The values to cache. + * @returns {null|Object} Returns the new cache object if `Set` is supported, else `null`. + */ + function createCache(values) { + return (nativeCreate && Set) ? new SetCache(values) : null; + } + + /** + * Creates a function that produces compound words out of the words in a + * given string. + * + * @private + * @param {Function} callback The function to combine each word. + * @returns {Function} Returns the new compounder function. + */ + function createCompounder(callback) { + return function(string) { + var index = -1, + array = words(deburr(string)), + length = array.length, + result = ''; + + while (++index < length) { + result = callback(result, array[index], index); + } + return result; + }; + } + + /** + * Creates a function that produces an instance of `Ctor` regardless of + * whether it was invoked as part of a `new` expression or by `call` or `apply`. + * + * @private + * @param {Function} Ctor The constructor to wrap. + * @returns {Function} Returns the new wrapped function. + */ + function createCtorWrapper(Ctor) { + return function() { + // Use a `switch` statement to work with class constructors. + // See http://ecma-international.org/ecma-262/6.0/#sec-ecmascript-function-objects-call-thisargument-argumentslist + // for more details. + var args = arguments; + switch (args.length) { + case 0: return new Ctor; + case 1: return new Ctor(args[0]); + case 2: return new Ctor(args[0], args[1]); + case 3: return new Ctor(args[0], args[1], args[2]); + case 4: return new Ctor(args[0], args[1], args[2], args[3]); + case 5: return new Ctor(args[0], args[1], args[2], args[3], args[4]); + case 6: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5]); + case 7: return new Ctor(args[0], args[1], args[2], args[3], args[4], args[5], args[6]); + } + var thisBinding = baseCreate(Ctor.prototype), + result = Ctor.apply(thisBinding, args); + + // Mimic the constructor's `return` behavior. + // See https://es5.github.io/#x13.2.2 for more details. + return isObject(result) ? result : thisBinding; + }; + } + + /** + * Creates a `_.curry` or `_.curryRight` function. + * + * @private + * @param {boolean} flag The curry bit flag. + * @returns {Function} Returns the new curry function. + */ + function createCurry(flag) { + function curryFunc(func, arity, guard) { + if (guard && isIterateeCall(func, arity, guard)) { + arity = undefined; + } + var result = createWrapper(func, flag, undefined, undefined, undefined, undefined, undefined, arity); + result.placeholder = curryFunc.placeholder; + return result; + } + return curryFunc; + } + + /** + * Creates a `_.defaults` or `_.defaultsDeep` function. + * + * @private + * @param {Function} assigner The function to assign values. + * @param {Function} customizer The function to customize assigned values. + * @returns {Function} Returns the new defaults function. + */ + function createDefaults(assigner, customizer) { + return restParam(function(args) { + var object = args[0]; + if (object == null) { + return object; + } + args.push(customizer); + return assigner.apply(undefined, args); + }); + } + + /** + * Creates a `_.max` or `_.min` function. + * + * @private + * @param {Function} comparator The function used to compare values. + * @param {*} exValue The initial extremum value. + * @returns {Function} Returns the new extremum function. + */ + function createExtremum(comparator, exValue) { + return function(collection, iteratee, thisArg) { + if (thisArg && isIterateeCall(collection, iteratee, thisArg)) { + iteratee = undefined; + } + iteratee = getCallback(iteratee, thisArg, 3); + if (iteratee.length == 1) { + collection = isArray(collection) ? collection : toIterable(collection); + var result = arrayExtremum(collection, iteratee, comparator, exValue); + if (!(collection.length && result === exValue)) { + return result; + } + } + return baseExtremum(collection, iteratee, comparator, exValue); + }; + } + + /** + * Creates a `_.find` or `_.findLast` function. + * + * @private + * @param {Function} eachFunc The function to iterate over a collection. + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {Function} Returns the new find function. + */ + function createFind(eachFunc, fromRight) { + return function(collection, predicate, thisArg) { + predicate = getCallback(predicate, thisArg, 3); + if (isArray(collection)) { + var index = baseFindIndex(collection, predicate, fromRight); + return index > -1 ? collection[index] : undefined; + } + return baseFind(collection, predicate, eachFunc); + }; + } + + /** + * Creates a `_.findIndex` or `_.findLastIndex` function. + * + * @private + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {Function} Returns the new find function. + */ + function createFindIndex(fromRight) { + return function(array, predicate, thisArg) { + if (!(array && array.length)) { + return -1; + } + predicate = getCallback(predicate, thisArg, 3); + return baseFindIndex(array, predicate, fromRight); + }; + } + + /** + * Creates a `_.findKey` or `_.findLastKey` function. + * + * @private + * @param {Function} objectFunc The function to iterate over an object. + * @returns {Function} Returns the new find function. + */ + function createFindKey(objectFunc) { + return function(object, predicate, thisArg) { + predicate = getCallback(predicate, thisArg, 3); + return baseFind(object, predicate, objectFunc, true); + }; + } + + /** + * Creates a `_.flow` or `_.flowRight` function. + * + * @private + * @param {boolean} [fromRight] Specify iterating from right to left. + * @returns {Function} Returns the new flow function. + */ + function createFlow(fromRight) { + return function() { + var wrapper, + length = arguments.length, + index = fromRight ? length : -1, + leftIndex = 0, + funcs = Array(length); + + while ((fromRight ? index-- : ++index < length)) { + var func = funcs[leftIndex++] = arguments[index]; + if (typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + if (!wrapper && LodashWrapper.prototype.thru && getFuncName(func) == 'wrapper') { + wrapper = new LodashWrapper([], true); + } + } + index = wrapper ? -1 : length; + while (++index < length) { + func = funcs[index]; + + var funcName = getFuncName(func), + data = funcName == 'wrapper' ? getData(func) : undefined; + + if (data && isLaziable(data[0]) && data[1] == (ARY_FLAG | CURRY_FLAG | PARTIAL_FLAG | REARG_FLAG) && !data[4].length && data[9] == 1) { + wrapper = wrapper[getFuncName(data[0])].apply(wrapper, data[3]); + } else { + wrapper = (func.length == 1 && isLaziable(func)) ? wrapper[funcName]() : wrapper.thru(func); + } + } + return function() { + var args = arguments, + value = args[0]; + + if (wrapper && args.length == 1 && isArray(value) && value.length >= LARGE_ARRAY_SIZE) { + return wrapper.plant(value).value(); + } + var index = 0, + result = length ? funcs[index].apply(this, args) : value; + + while (++index < length) { + result = funcs[index].call(this, result); + } + return result; + }; + }; + } + + /** + * Creates a function for `_.forEach` or `_.forEachRight`. + * + * @private + * @param {Function} arrayFunc The function to iterate over an array. + * @param {Function} eachFunc The function to iterate over a collection. + * @returns {Function} Returns the new each function. + */ + function createForEach(arrayFunc, eachFunc) { + return function(collection, iteratee, thisArg) { + return (typeof iteratee == 'function' && thisArg === undefined && isArray(collection)) + ? arrayFunc(collection, iteratee) + : eachFunc(collection, bindCallback(iteratee, thisArg, 3)); + }; + } + + /** + * Creates a function for `_.forIn` or `_.forInRight`. + * + * @private + * @param {Function} objectFunc The function to iterate over an object. + * @returns {Function} Returns the new each function. + */ + function createForIn(objectFunc) { + return function(object, iteratee, thisArg) { + if (typeof iteratee != 'function' || thisArg !== undefined) { + iteratee = bindCallback(iteratee, thisArg, 3); + } + return objectFunc(object, iteratee, keysIn); + }; + } + + /** + * Creates a function for `_.forOwn` or `_.forOwnRight`. + * + * @private + * @param {Function} objectFunc The function to iterate over an object. + * @returns {Function} Returns the new each function. + */ + function createForOwn(objectFunc) { + return function(object, iteratee, thisArg) { + if (typeof iteratee != 'function' || thisArg !== undefined) { + iteratee = bindCallback(iteratee, thisArg, 3); + } + return objectFunc(object, iteratee); + }; + } + + /** + * Creates a function for `_.mapKeys` or `_.mapValues`. + * + * @private + * @param {boolean} [isMapKeys] Specify mapping keys instead of values. + * @returns {Function} Returns the new map function. + */ + function createObjectMapper(isMapKeys) { + return function(object, iteratee, thisArg) { + var result = {}; + iteratee = getCallback(iteratee, thisArg, 3); + + baseForOwn(object, function(value, key, object) { + var mapped = iteratee(value, key, object); + key = isMapKeys ? mapped : key; + value = isMapKeys ? value : mapped; + result[key] = value; + }); + return result; + }; + } + + /** + * Creates a function for `_.padLeft` or `_.padRight`. + * + * @private + * @param {boolean} [fromRight] Specify padding from the right. + * @returns {Function} Returns the new pad function. + */ + function createPadDir(fromRight) { + return function(string, length, chars) { + string = baseToString(string); + return (fromRight ? string : '') + createPadding(string, length, chars) + (fromRight ? '' : string); + }; + } + + /** + * Creates a `_.partial` or `_.partialRight` function. + * + * @private + * @param {boolean} flag The partial bit flag. + * @returns {Function} Returns the new partial function. + */ + function createPartial(flag) { + var partialFunc = restParam(function(func, partials) { + var holders = replaceHolders(partials, partialFunc.placeholder); + return createWrapper(func, flag, undefined, partials, holders); + }); + return partialFunc; + } + + /** + * Creates a function for `_.reduce` or `_.reduceRight`. + * + * @private + * @param {Function} arrayFunc The function to iterate over an array. + * @param {Function} eachFunc The function to iterate over a collection. + * @returns {Function} Returns the new each function. + */ + function createReduce(arrayFunc, eachFunc) { + return function(collection, iteratee, accumulator, thisArg) { + var initFromArray = arguments.length < 3; + return (typeof iteratee == 'function' && thisArg === undefined && isArray(collection)) + ? arrayFunc(collection, iteratee, accumulator, initFromArray) + : baseReduce(collection, getCallback(iteratee, thisArg, 4), accumulator, initFromArray, eachFunc); + }; + } + + /** + * Creates a function that wraps `func` and invokes it with optional `this` + * binding of, partial application, and currying. + * + * @private + * @param {Function|string} func The function or method name to reference. + * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details. + * @param {*} [thisArg] The `this` binding of `func`. + * @param {Array} [partials] The arguments to prepend to those provided to the new function. + * @param {Array} [holders] The `partials` placeholder indexes. + * @param {Array} [partialsRight] The arguments to append to those provided to the new function. + * @param {Array} [holdersRight] The `partialsRight` placeholder indexes. + * @param {Array} [argPos] The argument positions of the new function. + * @param {number} [ary] The arity cap of `func`. + * @param {number} [arity] The arity of `func`. + * @returns {Function} Returns the new wrapped function. + */ + function createHybridWrapper(func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity) { + var isAry = bitmask & ARY_FLAG, + isBind = bitmask & BIND_FLAG, + isBindKey = bitmask & BIND_KEY_FLAG, + isCurry = bitmask & CURRY_FLAG, + isCurryBound = bitmask & CURRY_BOUND_FLAG, + isCurryRight = bitmask & CURRY_RIGHT_FLAG, + Ctor = isBindKey ? undefined : createCtorWrapper(func); + + function wrapper() { + // Avoid `arguments` object use disqualifying optimizations by + // converting it to an array before providing it to other functions. + var length = arguments.length, + index = length, + args = Array(length); + + while (index--) { + args[index] = arguments[index]; + } + if (partials) { + args = composeArgs(args, partials, holders); + } + if (partialsRight) { + args = composeArgsRight(args, partialsRight, holdersRight); + } + if (isCurry || isCurryRight) { + var placeholder = wrapper.placeholder, + argsHolders = replaceHolders(args, placeholder); + + length -= argsHolders.length; + if (length < arity) { + var newArgPos = argPos ? arrayCopy(argPos) : undefined, + newArity = nativeMax(arity - length, 0), + newsHolders = isCurry ? argsHolders : undefined, + newHoldersRight = isCurry ? undefined : argsHolders, + newPartials = isCurry ? args : undefined, + newPartialsRight = isCurry ? undefined : args; + + bitmask |= (isCurry ? PARTIAL_FLAG : PARTIAL_RIGHT_FLAG); + bitmask &= ~(isCurry ? PARTIAL_RIGHT_FLAG : PARTIAL_FLAG); + + if (!isCurryBound) { + bitmask &= ~(BIND_FLAG | BIND_KEY_FLAG); + } + var newData = [func, bitmask, thisArg, newPartials, newsHolders, newPartialsRight, newHoldersRight, newArgPos, ary, newArity], + result = createHybridWrapper.apply(undefined, newData); + + if (isLaziable(func)) { + setData(result, newData); + } + result.placeholder = placeholder; + return result; + } + } + var thisBinding = isBind ? thisArg : this, + fn = isBindKey ? thisBinding[func] : func; + + if (argPos) { + args = reorder(args, argPos); + } + if (isAry && ary < args.length) { + args.length = ary; + } + if (this && this !== root && this instanceof wrapper) { + fn = Ctor || createCtorWrapper(func); + } + return fn.apply(thisBinding, args); + } + return wrapper; + } + + /** + * Creates the padding required for `string` based on the given `length`. + * The `chars` string is truncated if the number of characters exceeds `length`. + * + * @private + * @param {string} string The string to create padding for. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the pad for `string`. + */ + function createPadding(string, length, chars) { + var strLength = string.length; + length = +length; + + if (strLength >= length || !nativeIsFinite(length)) { + return ''; + } + var padLength = length - strLength; + chars = chars == null ? ' ' : (chars + ''); + return repeat(chars, nativeCeil(padLength / chars.length)).slice(0, padLength); + } + + /** + * Creates a function that wraps `func` and invokes it with the optional `this` + * binding of `thisArg` and the `partials` prepended to those provided to + * the wrapper. + * + * @private + * @param {Function} func The function to partially apply arguments to. + * @param {number} bitmask The bitmask of flags. See `createWrapper` for more details. + * @param {*} thisArg The `this` binding of `func`. + * @param {Array} partials The arguments to prepend to those provided to the new function. + * @returns {Function} Returns the new bound function. + */ + function createPartialWrapper(func, bitmask, thisArg, partials) { + var isBind = bitmask & BIND_FLAG, + Ctor = createCtorWrapper(func); + + function wrapper() { + // Avoid `arguments` object use disqualifying optimizations by + // converting it to an array before providing it `func`. + var argsIndex = -1, + argsLength = arguments.length, + leftIndex = -1, + leftLength = partials.length, + args = Array(leftLength + argsLength); + + while (++leftIndex < leftLength) { + args[leftIndex] = partials[leftIndex]; + } + while (argsLength--) { + args[leftIndex++] = arguments[++argsIndex]; + } + var fn = (this && this !== root && this instanceof wrapper) ? Ctor : func; + return fn.apply(isBind ? thisArg : this, args); + } + return wrapper; + } + + /** + * Creates a `_.ceil`, `_.floor`, or `_.round` function. + * + * @private + * @param {string} methodName The name of the `Math` method to use when rounding. + * @returns {Function} Returns the new round function. + */ + function createRound(methodName) { + var func = Math[methodName]; + return function(number, precision) { + precision = precision === undefined ? 0 : (+precision || 0); + if (precision) { + precision = pow(10, precision); + return func(number * precision) / precision; + } + return func(number); + }; + } + + /** + * Creates a `_.sortedIndex` or `_.sortedLastIndex` function. + * + * @private + * @param {boolean} [retHighest] Specify returning the highest qualified index. + * @returns {Function} Returns the new index function. + */ + function createSortedIndex(retHighest) { + return function(array, value, iteratee, thisArg) { + var callback = getCallback(iteratee); + return (iteratee == null && callback === baseCallback) + ? binaryIndex(array, value, retHighest) + : binaryIndexBy(array, value, callback(iteratee, thisArg, 1), retHighest); + }; + } + + /** + * Creates a function that either curries or invokes `func` with optional + * `this` binding and partially applied arguments. + * + * @private + * @param {Function|string} func The function or method name to reference. + * @param {number} bitmask The bitmask of flags. + * The bitmask may be composed of the following flags: + * 1 - `_.bind` + * 2 - `_.bindKey` + * 4 - `_.curry` or `_.curryRight` of a bound function + * 8 - `_.curry` + * 16 - `_.curryRight` + * 32 - `_.partial` + * 64 - `_.partialRight` + * 128 - `_.rearg` + * 256 - `_.ary` + * @param {*} [thisArg] The `this` binding of `func`. + * @param {Array} [partials] The arguments to be partially applied. + * @param {Array} [holders] The `partials` placeholder indexes. + * @param {Array} [argPos] The argument positions of the new function. + * @param {number} [ary] The arity cap of `func`. + * @param {number} [arity] The arity of `func`. + * @returns {Function} Returns the new wrapped function. + */ + function createWrapper(func, bitmask, thisArg, partials, holders, argPos, ary, arity) { + var isBindKey = bitmask & BIND_KEY_FLAG; + if (!isBindKey && typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + var length = partials ? partials.length : 0; + if (!length) { + bitmask &= ~(PARTIAL_FLAG | PARTIAL_RIGHT_FLAG); + partials = holders = undefined; + } + length -= (holders ? holders.length : 0); + if (bitmask & PARTIAL_RIGHT_FLAG) { + var partialsRight = partials, + holdersRight = holders; + + partials = holders = undefined; + } + var data = isBindKey ? undefined : getData(func), + newData = [func, bitmask, thisArg, partials, holders, partialsRight, holdersRight, argPos, ary, arity]; + + if (data) { + mergeData(newData, data); + bitmask = newData[1]; + arity = newData[9]; + } + newData[9] = arity == null + ? (isBindKey ? 0 : func.length) + : (nativeMax(arity - length, 0) || 0); + + if (bitmask == BIND_FLAG) { + var result = createBindWrapper(newData[0], newData[2]); + } else if ((bitmask == PARTIAL_FLAG || bitmask == (BIND_FLAG | PARTIAL_FLAG)) && !newData[4].length) { + result = createPartialWrapper.apply(undefined, newData); + } else { + result = createHybridWrapper.apply(undefined, newData); + } + var setter = data ? baseSetData : setData; + return setter(result, newData); + } + + /** + * A specialized version of `baseIsEqualDeep` for arrays with support for + * partial deep comparisons. + * + * @private + * @param {Array} array The array to compare. + * @param {Array} other The other array to compare. + * @param {Function} equalFunc The function to determine equivalents of values. + * @param {Function} [customizer] The function to customize comparing arrays. + * @param {boolean} [isLoose] Specify performing partial comparisons. + * @param {Array} [stackA] Tracks traversed `value` objects. + * @param {Array} [stackB] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the arrays are equivalent, else `false`. + */ + function equalArrays(array, other, equalFunc, customizer, isLoose, stackA, stackB) { + var index = -1, + arrLength = array.length, + othLength = other.length; + + if (arrLength != othLength && !(isLoose && othLength > arrLength)) { + return false; + } + // Ignore non-index properties. + while (++index < arrLength) { + var arrValue = array[index], + othValue = other[index], + result = customizer ? customizer(isLoose ? othValue : arrValue, isLoose ? arrValue : othValue, index) : undefined; + + if (result !== undefined) { + if (result) { + continue; + } + return false; + } + // Recursively compare arrays (susceptible to call stack limits). + if (isLoose) { + if (!arraySome(other, function(othValue) { + return arrValue === othValue || equalFunc(arrValue, othValue, customizer, isLoose, stackA, stackB); + })) { + return false; + } + } else if (!(arrValue === othValue || equalFunc(arrValue, othValue, customizer, isLoose, stackA, stackB))) { + return false; + } + } + return true; + } + + /** + * A specialized version of `baseIsEqualDeep` for comparing objects of + * the same `toStringTag`. + * + * **Note:** This function only supports comparing values with tags of + * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`. + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @param {string} tag The `toStringTag` of the objects to compare. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function equalByTag(object, other, tag) { + switch (tag) { + case boolTag: + case dateTag: + // Coerce dates and booleans to numbers, dates to milliseconds and booleans + // to `1` or `0` treating invalid dates coerced to `NaN` as not equal. + return +object == +other; + + case errorTag: + return object.name == other.name && object.message == other.message; + + case numberTag: + // Treat `NaN` vs. `NaN` as equal. + return (object != +object) + ? other != +other + : object == +other; + + case regexpTag: + case stringTag: + // Coerce regexes to strings and treat strings primitives and string + // objects as equal. See https://es5.github.io/#x15.10.6.4 for more details. + return object == (other + ''); + } + return false; + } + + /** + * A specialized version of `baseIsEqualDeep` for objects with support for + * partial deep comparisons. + * + * @private + * @param {Object} object The object to compare. + * @param {Object} other The other object to compare. + * @param {Function} equalFunc The function to determine equivalents of values. + * @param {Function} [customizer] The function to customize comparing values. + * @param {boolean} [isLoose] Specify performing partial comparisons. + * @param {Array} [stackA] Tracks traversed `value` objects. + * @param {Array} [stackB] Tracks traversed `other` objects. + * @returns {boolean} Returns `true` if the objects are equivalent, else `false`. + */ + function equalObjects(object, other, equalFunc, customizer, isLoose, stackA, stackB) { + var objProps = keys(object), + objLength = objProps.length, + othProps = keys(other), + othLength = othProps.length; + + if (objLength != othLength && !isLoose) { + return false; + } + var index = objLength; + while (index--) { + var key = objProps[index]; + if (!(isLoose ? key in other : hasOwnProperty.call(other, key))) { + return false; + } + } + var skipCtor = isLoose; + while (++index < objLength) { + key = objProps[index]; + var objValue = object[key], + othValue = other[key], + result = customizer ? customizer(isLoose ? othValue : objValue, isLoose? objValue : othValue, key) : undefined; + + // Recursively compare objects (susceptible to call stack limits). + if (!(result === undefined ? equalFunc(objValue, othValue, customizer, isLoose, stackA, stackB) : result)) { + return false; + } + skipCtor || (skipCtor = key == 'constructor'); + } + if (!skipCtor) { + var objCtor = object.constructor, + othCtor = other.constructor; + + // Non `Object` object instances with different constructors are not equal. + if (objCtor != othCtor && + ('constructor' in object && 'constructor' in other) && + !(typeof objCtor == 'function' && objCtor instanceof objCtor && + typeof othCtor == 'function' && othCtor instanceof othCtor)) { + return false; + } + } + return true; + } + + /** + * Gets the appropriate "callback" function. If the `_.callback` method is + * customized this function returns the custom method, otherwise it returns + * the `baseCallback` function. If arguments are provided the chosen function + * is invoked with them and its result is returned. + * + * @private + * @returns {Function} Returns the chosen function or its result. + */ + function getCallback(func, thisArg, argCount) { + var result = lodash.callback || callback; + result = result === callback ? baseCallback : result; + return argCount ? result(func, thisArg, argCount) : result; + } + + /** + * Gets metadata for `func`. + * + * @private + * @param {Function} func The function to query. + * @returns {*} Returns the metadata for `func`. + */ + var getData = !metaMap ? noop : function(func) { + return metaMap.get(func); + }; + + /** + * Gets the name of `func`. + * + * @private + * @param {Function} func The function to query. + * @returns {string} Returns the function name. + */ + function getFuncName(func) { + var result = func.name, + array = realNames[result], + length = array ? array.length : 0; + + while (length--) { + var data = array[length], + otherFunc = data.func; + if (otherFunc == null || otherFunc == func) { + return data.name; + } + } + return result; + } + + /** + * Gets the appropriate "indexOf" function. If the `_.indexOf` method is + * customized this function returns the custom method, otherwise it returns + * the `baseIndexOf` function. If arguments are provided the chosen function + * is invoked with them and its result is returned. + * + * @private + * @returns {Function|number} Returns the chosen function or its result. + */ + function getIndexOf(collection, target, fromIndex) { + var result = lodash.indexOf || indexOf; + result = result === indexOf ? baseIndexOf : result; + return collection ? result(collection, target, fromIndex) : result; + } + + /** + * Gets the "length" property value of `object`. + * + * **Note:** This function is used to avoid a [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792) + * that affects Safari on at least iOS 8.1-8.3 ARM64. + * + * @private + * @param {Object} object The object to query. + * @returns {*} Returns the "length" value. + */ + var getLength = baseProperty('length'); + + /** + * Gets the propery names, values, and compare flags of `object`. + * + * @private + * @param {Object} object The object to query. + * @returns {Array} Returns the match data of `object`. + */ + function getMatchData(object) { + var result = pairs(object), + length = result.length; + + while (length--) { + result[length][2] = isStrictComparable(result[length][1]); + } + return result; + } + + /** + * Gets the native function at `key` of `object`. + * + * @private + * @param {Object} object The object to query. + * @param {string} key The key of the method to get. + * @returns {*} Returns the function if it's native, else `undefined`. + */ + function getNative(object, key) { + var value = object == null ? undefined : object[key]; + return isNative(value) ? value : undefined; + } + + /** + * Gets the view, applying any `transforms` to the `start` and `end` positions. + * + * @private + * @param {number} start The start of the view. + * @param {number} end The end of the view. + * @param {Array} transforms The transformations to apply to the view. + * @returns {Object} Returns an object containing the `start` and `end` + * positions of the view. + */ + function getView(start, end, transforms) { + var index = -1, + length = transforms.length; + + while (++index < length) { + var data = transforms[index], + size = data.size; + + switch (data.type) { + case 'drop': start += size; break; + case 'dropRight': end -= size; break; + case 'take': end = nativeMin(end, start + size); break; + case 'takeRight': start = nativeMax(start, end - size); break; + } + } + return { 'start': start, 'end': end }; + } + + /** + * Initializes an array clone. + * + * @private + * @param {Array} array The array to clone. + * @returns {Array} Returns the initialized clone. + */ + function initCloneArray(array) { + var length = array.length, + result = new array.constructor(length); + + // Add array properties assigned by `RegExp#exec`. + if (length && typeof array[0] == 'string' && hasOwnProperty.call(array, 'index')) { + result.index = array.index; + result.input = array.input; + } + return result; + } + + /** + * Initializes an object clone. + * + * @private + * @param {Object} object The object to clone. + * @returns {Object} Returns the initialized clone. + */ + function initCloneObject(object) { + var Ctor = object.constructor; + if (!(typeof Ctor == 'function' && Ctor instanceof Ctor)) { + Ctor = Object; + } + return new Ctor; + } + + /** + * Initializes an object clone based on its `toStringTag`. + * + * **Note:** This function only supports cloning values with tags of + * `Boolean`, `Date`, `Error`, `Number`, `RegExp`, or `String`. + * + * @private + * @param {Object} object The object to clone. + * @param {string} tag The `toStringTag` of the object to clone. + * @param {boolean} [isDeep] Specify a deep clone. + * @returns {Object} Returns the initialized clone. + */ + function initCloneByTag(object, tag, isDeep) { + var Ctor = object.constructor; + switch (tag) { + case arrayBufferTag: + return bufferClone(object); + + case boolTag: + case dateTag: + return new Ctor(+object); + + case float32Tag: case float64Tag: + case int8Tag: case int16Tag: case int32Tag: + case uint8Tag: case uint8ClampedTag: case uint16Tag: case uint32Tag: + var buffer = object.buffer; + return new Ctor(isDeep ? bufferClone(buffer) : buffer, object.byteOffset, object.length); + + case numberTag: + case stringTag: + return new Ctor(object); + + case regexpTag: + var result = new Ctor(object.source, reFlags.exec(object)); + result.lastIndex = object.lastIndex; + } + return result; + } + + /** + * Invokes the method at `path` on `object`. + * + * @private + * @param {Object} object The object to query. + * @param {Array|string} path The path of the method to invoke. + * @param {Array} args The arguments to invoke the method with. + * @returns {*} Returns the result of the invoked method. + */ + function invokePath(object, path, args) { + if (object != null && !isKey(path, object)) { + path = toPath(path); + object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1)); + path = last(path); + } + var func = object == null ? object : object[path]; + return func == null ? undefined : func.apply(object, args); + } + + /** + * Checks if `value` is array-like. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is array-like, else `false`. + */ + function isArrayLike(value) { + return value != null && isLength(getLength(value)); + } + + /** + * Checks if `value` is a valid array-like index. + * + * @private + * @param {*} value The value to check. + * @param {number} [length=MAX_SAFE_INTEGER] The upper bounds of a valid index. + * @returns {boolean} Returns `true` if `value` is a valid index, else `false`. + */ + function isIndex(value, length) { + value = (typeof value == 'number' || reIsUint.test(value)) ? +value : -1; + length = length == null ? MAX_SAFE_INTEGER : length; + return value > -1 && value % 1 == 0 && value < length; + } + + /** + * Checks if the provided arguments are from an iteratee call. + * + * @private + * @param {*} value The potential iteratee value argument. + * @param {*} index The potential iteratee index or key argument. + * @param {*} object The potential iteratee object argument. + * @returns {boolean} Returns `true` if the arguments are from an iteratee call, else `false`. + */ + function isIterateeCall(value, index, object) { + if (!isObject(object)) { + return false; + } + var type = typeof index; + if (type == 'number' + ? (isArrayLike(object) && isIndex(index, object.length)) + : (type == 'string' && index in object)) { + var other = object[index]; + return value === value ? (value === other) : (other !== other); + } + return false; + } + + /** + * Checks if `value` is a property name and not a property path. + * + * @private + * @param {*} value The value to check. + * @param {Object} [object] The object to query keys on. + * @returns {boolean} Returns `true` if `value` is a property name, else `false`. + */ + function isKey(value, object) { + var type = typeof value; + if ((type == 'string' && reIsPlainProp.test(value)) || type == 'number') { + return true; + } + if (isArray(value)) { + return false; + } + var result = !reIsDeepProp.test(value); + return result || (object != null && value in toObject(object)); + } + + /** + * Checks if `func` has a lazy counterpart. + * + * @private + * @param {Function} func The function to check. + * @returns {boolean} Returns `true` if `func` has a lazy counterpart, else `false`. + */ + function isLaziable(func) { + var funcName = getFuncName(func); + if (!(funcName in LazyWrapper.prototype)) { + return false; + } + var other = lodash[funcName]; + if (func === other) { + return true; + } + var data = getData(other); + return !!data && func === data[0]; + } + + /** + * Checks if `value` is a valid array-like length. + * + * **Note:** This function is based on [`ToLength`](http://ecma-international.org/ecma-262/6.0/#sec-tolength). + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a valid length, else `false`. + */ + function isLength(value) { + return typeof value == 'number' && value > -1 && value % 1 == 0 && value <= MAX_SAFE_INTEGER; + } + + /** + * Checks if `value` is suitable for strict equality comparisons, i.e. `===`. + * + * @private + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` if suitable for strict + * equality comparisons, else `false`. + */ + function isStrictComparable(value) { + return value === value && !isObject(value); + } + + /** + * Merges the function metadata of `source` into `data`. + * + * Merging metadata reduces the number of wrappers required to invoke a function. + * This is possible because methods like `_.bind`, `_.curry`, and `_.partial` + * may be applied regardless of execution order. Methods like `_.ary` and `_.rearg` + * augment function arguments, making the order in which they are executed important, + * preventing the merging of metadata. However, we make an exception for a safe + * common case where curried functions have `_.ary` and or `_.rearg` applied. + * + * @private + * @param {Array} data The destination metadata. + * @param {Array} source The source metadata. + * @returns {Array} Returns `data`. + */ + function mergeData(data, source) { + var bitmask = data[1], + srcBitmask = source[1], + newBitmask = bitmask | srcBitmask, + isCommon = newBitmask < ARY_FLAG; + + var isCombo = + (srcBitmask == ARY_FLAG && bitmask == CURRY_FLAG) || + (srcBitmask == ARY_FLAG && bitmask == REARG_FLAG && data[7].length <= source[8]) || + (srcBitmask == (ARY_FLAG | REARG_FLAG) && bitmask == CURRY_FLAG); + + // Exit early if metadata can't be merged. + if (!(isCommon || isCombo)) { + return data; + } + // Use source `thisArg` if available. + if (srcBitmask & BIND_FLAG) { + data[2] = source[2]; + // Set when currying a bound function. + newBitmask |= (bitmask & BIND_FLAG) ? 0 : CURRY_BOUND_FLAG; + } + // Compose partial arguments. + var value = source[3]; + if (value) { + var partials = data[3]; + data[3] = partials ? composeArgs(partials, value, source[4]) : arrayCopy(value); + data[4] = partials ? replaceHolders(data[3], PLACEHOLDER) : arrayCopy(source[4]); + } + // Compose partial right arguments. + value = source[5]; + if (value) { + partials = data[5]; + data[5] = partials ? composeArgsRight(partials, value, source[6]) : arrayCopy(value); + data[6] = partials ? replaceHolders(data[5], PLACEHOLDER) : arrayCopy(source[6]); + } + // Use source `argPos` if available. + value = source[7]; + if (value) { + data[7] = arrayCopy(value); + } + // Use source `ary` if it's smaller. + if (srcBitmask & ARY_FLAG) { + data[8] = data[8] == null ? source[8] : nativeMin(data[8], source[8]); + } + // Use source `arity` if one is not provided. + if (data[9] == null) { + data[9] = source[9]; + } + // Use source `func` and merge bitmasks. + data[0] = source[0]; + data[1] = newBitmask; + + return data; + } + + /** + * Used by `_.defaultsDeep` to customize its `_.merge` use. + * + * @private + * @param {*} objectValue The destination object property value. + * @param {*} sourceValue The source object property value. + * @returns {*} Returns the value to assign to the destination object. + */ + function mergeDefaults(objectValue, sourceValue) { + return objectValue === undefined ? sourceValue : merge(objectValue, sourceValue, mergeDefaults); + } + + /** + * A specialized version of `_.pick` which picks `object` properties specified + * by `props`. + * + * @private + * @param {Object} object The source object. + * @param {string[]} props The property names to pick. + * @returns {Object} Returns the new object. + */ + function pickByArray(object, props) { + object = toObject(object); + + var index = -1, + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index]; + if (key in object) { + result[key] = object[key]; + } + } + return result; + } + + /** + * A specialized version of `_.pick` which picks `object` properties `predicate` + * returns truthy for. + * + * @private + * @param {Object} object The source object. + * @param {Function} predicate The function invoked per iteration. + * @returns {Object} Returns the new object. + */ + function pickByCallback(object, predicate) { + var result = {}; + baseForIn(object, function(value, key, object) { + if (predicate(value, key, object)) { + result[key] = value; + } + }); + return result; + } + + /** + * Reorder `array` according to the specified indexes where the element at + * the first index is assigned as the first element, the element at + * the second index is assigned as the second element, and so on. + * + * @private + * @param {Array} array The array to reorder. + * @param {Array} indexes The arranged array indexes. + * @returns {Array} Returns `array`. + */ + function reorder(array, indexes) { + var arrLength = array.length, + length = nativeMin(indexes.length, arrLength), + oldArray = arrayCopy(array); + + while (length--) { + var index = indexes[length]; + array[length] = isIndex(index, arrLength) ? oldArray[index] : undefined; + } + return array; + } + + /** + * Sets metadata for `func`. + * + * **Note:** If this function becomes hot, i.e. is invoked a lot in a short + * period of time, it will trip its breaker and transition to an identity function + * to avoid garbage collection pauses in V8. See [V8 issue 2070](https://code.google.com/p/v8/issues/detail?id=2070) + * for more details. + * + * @private + * @param {Function} func The function to associate metadata with. + * @param {*} data The metadata. + * @returns {Function} Returns `func`. + */ + var setData = (function() { + var count = 0, + lastCalled = 0; + + return function(key, value) { + var stamp = now(), + remaining = HOT_SPAN - (stamp - lastCalled); + + lastCalled = stamp; + if (remaining > 0) { + if (++count >= HOT_COUNT) { + return key; + } + } else { + count = 0; + } + return baseSetData(key, value); + }; + }()); + + /** + * A fallback implementation of `Object.keys` which creates an array of the + * own enumerable property names of `object`. + * + * @private + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property names. + */ + function shimKeys(object) { + var props = keysIn(object), + propsLength = props.length, + length = propsLength && object.length; + + var allowIndexes = !!length && isLength(length) && + (isArray(object) || isArguments(object)); + + var index = -1, + result = []; + + while (++index < propsLength) { + var key = props[index]; + if ((allowIndexes && isIndex(key, length)) || hasOwnProperty.call(object, key)) { + result.push(key); + } + } + return result; + } + + /** + * Converts `value` to an array-like object if it's not one. + * + * @private + * @param {*} value The value to process. + * @returns {Array|Object} Returns the array-like object. + */ + function toIterable(value) { + if (value == null) { + return []; + } + if (!isArrayLike(value)) { + return values(value); + } + return isObject(value) ? value : Object(value); + } + + /** + * Converts `value` to an object if it's not one. + * + * @private + * @param {*} value The value to process. + * @returns {Object} Returns the object. + */ + function toObject(value) { + return isObject(value) ? value : Object(value); + } + + /** + * Converts `value` to property path array if it's not one. + * + * @private + * @param {*} value The value to process. + * @returns {Array} Returns the property path array. + */ + function toPath(value) { + if (isArray(value)) { + return value; + } + var result = []; + baseToString(value).replace(rePropName, function(match, number, quote, string) { + result.push(quote ? string.replace(reEscapeChar, '$1') : (number || match)); + }); + return result; + } + + /** + * Creates a clone of `wrapper`. + * + * @private + * @param {Object} wrapper The wrapper to clone. + * @returns {Object} Returns the cloned wrapper. + */ + function wrapperClone(wrapper) { + return wrapper instanceof LazyWrapper + ? wrapper.clone() + : new LodashWrapper(wrapper.__wrapped__, wrapper.__chain__, arrayCopy(wrapper.__actions__)); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates an array of elements split into groups the length of `size`. + * If `collection` can't be split evenly, the final chunk will be the remaining + * elements. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to process. + * @param {number} [size=1] The length of each chunk. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the new array containing chunks. + * @example + * + * _.chunk(['a', 'b', 'c', 'd'], 2); + * // => [['a', 'b'], ['c', 'd']] + * + * _.chunk(['a', 'b', 'c', 'd'], 3); + * // => [['a', 'b', 'c'], ['d']] + */ + function chunk(array, size, guard) { + if (guard ? isIterateeCall(array, size, guard) : size == null) { + size = 1; + } else { + size = nativeMax(nativeFloor(size) || 1, 1); + } + var index = 0, + length = array ? array.length : 0, + resIndex = -1, + result = Array(nativeCeil(length / size)); + + while (index < length) { + result[++resIndex] = baseSlice(array, index, (index += size)); + } + return result; + } + + /** + * Creates an array with all falsey values removed. The values `false`, `null`, + * `0`, `""`, `undefined`, and `NaN` are falsey. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to compact. + * @returns {Array} Returns the new array of filtered values. + * @example + * + * _.compact([0, 1, false, 2, '', 3]); + * // => [1, 2, 3] + */ + function compact(array) { + var index = -1, + length = array ? array.length : 0, + resIndex = -1, + result = []; + + while (++index < length) { + var value = array[index]; + if (value) { + result[++resIndex] = value; + } + } + return result; + } + + /** + * Creates an array of unique `array` values not included in the other + * provided arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to inspect. + * @param {...Array} [values] The arrays of values to exclude. + * @returns {Array} Returns the new array of filtered values. + * @example + * + * _.difference([1, 2, 3], [4, 2]); + * // => [1, 3] + */ + var difference = restParam(function(array, values) { + return (isObjectLike(array) && isArrayLike(array)) + ? baseDifference(array, baseFlatten(values, false, true)) + : []; + }); + + /** + * Creates a slice of `array` with `n` elements dropped from the beginning. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to drop. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.drop([1, 2, 3]); + * // => [2, 3] + * + * _.drop([1, 2, 3], 2); + * // => [3] + * + * _.drop([1, 2, 3], 5); + * // => [] + * + * _.drop([1, 2, 3], 0); + * // => [1, 2, 3] + */ + function drop(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + return baseSlice(array, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` with `n` elements dropped from the end. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to drop. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.dropRight([1, 2, 3]); + * // => [1, 2] + * + * _.dropRight([1, 2, 3], 2); + * // => [1] + * + * _.dropRight([1, 2, 3], 5); + * // => [] + * + * _.dropRight([1, 2, 3], 0); + * // => [1, 2, 3] + */ + function dropRight(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + n = length - (+n || 0); + return baseSlice(array, 0, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` excluding elements dropped from the end. + * Elements are dropped until `predicate` returns falsey. The predicate is + * bound to `thisArg` and invoked with three arguments: (value, index, array). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that match the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.dropRightWhile([1, 2, 3], function(n) { + * return n > 1; + * }); + * // => [1] + * + * var users = [ + * { 'user': 'barney', 'active': true }, + * { 'user': 'fred', 'active': false }, + * { 'user': 'pebbles', 'active': false } + * ]; + * + * // using the `_.matches` callback shorthand + * _.pluck(_.dropRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user'); + * // => ['barney', 'fred'] + * + * // using the `_.matchesProperty` callback shorthand + * _.pluck(_.dropRightWhile(users, 'active', false), 'user'); + * // => ['barney'] + * + * // using the `_.property` callback shorthand + * _.pluck(_.dropRightWhile(users, 'active'), 'user'); + * // => ['barney', 'fred', 'pebbles'] + */ + function dropRightWhile(array, predicate, thisArg) { + return (array && array.length) + ? baseWhile(array, getCallback(predicate, thisArg, 3), true, true) + : []; + } + + /** + * Creates a slice of `array` excluding elements dropped from the beginning. + * Elements are dropped until `predicate` returns falsey. The predicate is + * bound to `thisArg` and invoked with three arguments: (value, index, array). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.dropWhile([1, 2, 3], function(n) { + * return n < 3; + * }); + * // => [3] + * + * var users = [ + * { 'user': 'barney', 'active': false }, + * { 'user': 'fred', 'active': false }, + * { 'user': 'pebbles', 'active': true } + * ]; + * + * // using the `_.matches` callback shorthand + * _.pluck(_.dropWhile(users, { 'user': 'barney', 'active': false }), 'user'); + * // => ['fred', 'pebbles'] + * + * // using the `_.matchesProperty` callback shorthand + * _.pluck(_.dropWhile(users, 'active', false), 'user'); + * // => ['pebbles'] + * + * // using the `_.property` callback shorthand + * _.pluck(_.dropWhile(users, 'active'), 'user'); + * // => ['barney', 'fred', 'pebbles'] + */ + function dropWhile(array, predicate, thisArg) { + return (array && array.length) + ? baseWhile(array, getCallback(predicate, thisArg, 3), true) + : []; + } + + /** + * Fills elements of `array` with `value` from `start` up to, but not + * including, `end`. + * + * **Note:** This method mutates `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to fill. + * @param {*} value The value to fill `array` with. + * @param {number} [start=0] The start position. + * @param {number} [end=array.length] The end position. + * @returns {Array} Returns `array`. + * @example + * + * var array = [1, 2, 3]; + * + * _.fill(array, 'a'); + * console.log(array); + * // => ['a', 'a', 'a'] + * + * _.fill(Array(3), 2); + * // => [2, 2, 2] + * + * _.fill([4, 6, 8], '*', 1, 2); + * // => [4, '*', 8] + */ + function fill(array, value, start, end) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (start && typeof start != 'number' && isIterateeCall(array, value, start)) { + start = 0; + end = length; + } + return baseFill(array, value, start, end); + } + + /** + * This method is like `_.find` except that it returns the index of the first + * element `predicate` returns truthy for instead of the element itself. + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {number} Returns the index of the found element, else `-1`. + * @example + * + * var users = [ + * { 'user': 'barney', 'active': false }, + * { 'user': 'fred', 'active': false }, + * { 'user': 'pebbles', 'active': true } + * ]; + * + * _.findIndex(users, function(chr) { + * return chr.user == 'barney'; + * }); + * // => 0 + * + * // using the `_.matches` callback shorthand + * _.findIndex(users, { 'user': 'fred', 'active': false }); + * // => 1 + * + * // using the `_.matchesProperty` callback shorthand + * _.findIndex(users, 'active', false); + * // => 0 + * + * // using the `_.property` callback shorthand + * _.findIndex(users, 'active'); + * // => 2 + */ + var findIndex = createFindIndex(); + + /** + * This method is like `_.findIndex` except that it iterates over elements + * of `collection` from right to left. + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {number} Returns the index of the found element, else `-1`. + * @example + * + * var users = [ + * { 'user': 'barney', 'active': true }, + * { 'user': 'fred', 'active': false }, + * { 'user': 'pebbles', 'active': false } + * ]; + * + * _.findLastIndex(users, function(chr) { + * return chr.user == 'pebbles'; + * }); + * // => 2 + * + * // using the `_.matches` callback shorthand + * _.findLastIndex(users, { 'user': 'barney', 'active': true }); + * // => 0 + * + * // using the `_.matchesProperty` callback shorthand + * _.findLastIndex(users, 'active', false); + * // => 2 + * + * // using the `_.property` callback shorthand + * _.findLastIndex(users, 'active'); + * // => 0 + */ + var findLastIndex = createFindIndex(true); + + /** + * Gets the first element of `array`. + * + * @static + * @memberOf _ + * @alias head + * @category Array + * @param {Array} array The array to query. + * @returns {*} Returns the first element of `array`. + * @example + * + * _.first([1, 2, 3]); + * // => 1 + * + * _.first([]); + * // => undefined + */ + function first(array) { + return array ? array[0] : undefined; + } + + /** + * Flattens a nested array. If `isDeep` is `true` the array is recursively + * flattened, otherwise it is only flattened a single level. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to flatten. + * @param {boolean} [isDeep] Specify a deep flatten. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the new flattened array. + * @example + * + * _.flatten([1, [2, 3, [4]]]); + * // => [1, 2, 3, [4]] + * + * // using `isDeep` + * _.flatten([1, [2, 3, [4]]], true); + * // => [1, 2, 3, 4] + */ + function flatten(array, isDeep, guard) { + var length = array ? array.length : 0; + if (guard && isIterateeCall(array, isDeep, guard)) { + isDeep = false; + } + return length ? baseFlatten(array, isDeep) : []; + } + + /** + * Recursively flattens a nested array. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to recursively flatten. + * @returns {Array} Returns the new flattened array. + * @example + * + * _.flattenDeep([1, [2, 3, [4]]]); + * // => [1, 2, 3, 4] + */ + function flattenDeep(array) { + var length = array ? array.length : 0; + return length ? baseFlatten(array, true) : []; + } + + /** + * Gets the index at which the first occurrence of `value` is found in `array` + * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. If `fromIndex` is negative, it is used as the offset + * from the end of `array`. If `array` is sorted providing `true` for `fromIndex` + * performs a faster binary search. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {boolean|number} [fromIndex=0] The index to search from or `true` + * to perform a binary search on a sorted array. + * @returns {number} Returns the index of the matched value, else `-1`. + * @example + * + * _.indexOf([1, 2, 1, 2], 2); + * // => 1 + * + * // using `fromIndex` + * _.indexOf([1, 2, 1, 2], 2, 2); + * // => 3 + * + * // performing a binary search + * _.indexOf([1, 1, 2, 2], 2, true); + * // => 2 + */ + function indexOf(array, value, fromIndex) { + var length = array ? array.length : 0; + if (!length) { + return -1; + } + if (typeof fromIndex == 'number') { + fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : fromIndex; + } else if (fromIndex) { + var index = binaryIndex(array, value); + if (index < length && + (value === value ? (value === array[index]) : (array[index] !== array[index]))) { + return index; + } + return -1; + } + return baseIndexOf(array, value, fromIndex || 0); + } + + /** + * Gets all but the last element of `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.initial([1, 2, 3]); + * // => [1, 2] + */ + function initial(array) { + return dropRight(array, 1); + } + + /** + * Creates an array of unique values that are included in all of the provided + * arrays using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to inspect. + * @returns {Array} Returns the new array of shared values. + * @example + * _.intersection([1, 2], [4, 2], [2, 1]); + * // => [2] + */ + var intersection = restParam(function(arrays) { + var othLength = arrays.length, + othIndex = othLength, + caches = Array(length), + indexOf = getIndexOf(), + isCommon = indexOf == baseIndexOf, + result = []; + + while (othIndex--) { + var value = arrays[othIndex] = isArrayLike(value = arrays[othIndex]) ? value : []; + caches[othIndex] = (isCommon && value.length >= 120) ? createCache(othIndex && value) : null; + } + var array = arrays[0], + index = -1, + length = array ? array.length : 0, + seen = caches[0]; + + outer: + while (++index < length) { + value = array[index]; + if ((seen ? cacheIndexOf(seen, value) : indexOf(result, value, 0)) < 0) { + var othIndex = othLength; + while (--othIndex) { + var cache = caches[othIndex]; + if ((cache ? cacheIndexOf(cache, value) : indexOf(arrays[othIndex], value, 0)) < 0) { + continue outer; + } + } + if (seen) { + seen.push(value); + } + result.push(value); + } + } + return result; + }); + + /** + * Gets the last element of `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @returns {*} Returns the last element of `array`. + * @example + * + * _.last([1, 2, 3]); + * // => 3 + */ + function last(array) { + var length = array ? array.length : 0; + return length ? array[length - 1] : undefined; + } + + /** + * This method is like `_.indexOf` except that it iterates over elements of + * `array` from right to left. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to search. + * @param {*} value The value to search for. + * @param {boolean|number} [fromIndex=array.length-1] The index to search from + * or `true` to perform a binary search on a sorted array. + * @returns {number} Returns the index of the matched value, else `-1`. + * @example + * + * _.lastIndexOf([1, 2, 1, 2], 2); + * // => 3 + * + * // using `fromIndex` + * _.lastIndexOf([1, 2, 1, 2], 2, 2); + * // => 1 + * + * // performing a binary search + * _.lastIndexOf([1, 1, 2, 2], 2, true); + * // => 3 + */ + function lastIndexOf(array, value, fromIndex) { + var length = array ? array.length : 0; + if (!length) { + return -1; + } + var index = length; + if (typeof fromIndex == 'number') { + index = (fromIndex < 0 ? nativeMax(length + fromIndex, 0) : nativeMin(fromIndex || 0, length - 1)) + 1; + } else if (fromIndex) { + index = binaryIndex(array, value, true) - 1; + var other = array[index]; + if (value === value ? (value === other) : (other !== other)) { + return index; + } + return -1; + } + if (value !== value) { + return indexOfNaN(array, index, true); + } + while (index--) { + if (array[index] === value) { + return index; + } + } + return -1; + } + + /** + * Removes all provided values from `array` using + * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. + * + * **Note:** Unlike `_.without`, this method mutates `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to modify. + * @param {...*} [values] The values to remove. + * @returns {Array} Returns `array`. + * @example + * + * var array = [1, 2, 3, 1, 2, 3]; + * + * _.pull(array, 2, 3); + * console.log(array); + * // => [1, 1] + */ + function pull() { + var args = arguments, + array = args[0]; + + if (!(array && array.length)) { + return array; + } + var index = 0, + indexOf = getIndexOf(), + length = args.length; + + while (++index < length) { + var fromIndex = 0, + value = args[index]; + + while ((fromIndex = indexOf(array, value, fromIndex)) > -1) { + splice.call(array, fromIndex, 1); + } + } + return array; + } + + /** + * Removes elements from `array` corresponding to the given indexes and returns + * an array of the removed elements. Indexes may be specified as an array of + * indexes or as individual arguments. + * + * **Note:** Unlike `_.at`, this method mutates `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to modify. + * @param {...(number|number[])} [indexes] The indexes of elements to remove, + * specified as individual indexes or arrays of indexes. + * @returns {Array} Returns the new array of removed elements. + * @example + * + * var array = [5, 10, 15, 20]; + * var evens = _.pullAt(array, 1, 3); + * + * console.log(array); + * // => [5, 15] + * + * console.log(evens); + * // => [10, 20] + */ + var pullAt = restParam(function(array, indexes) { + indexes = baseFlatten(indexes); + + var result = baseAt(array, indexes); + basePullAt(array, indexes.sort(baseCompareAscending)); + return result; + }); + + /** + * Removes all elements from `array` that `predicate` returns truthy for + * and returns an array of the removed elements. The predicate is bound to + * `thisArg` and invoked with three arguments: (value, index, array). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * **Note:** Unlike `_.filter`, this method mutates `array`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to modify. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the new array of removed elements. + * @example + * + * var array = [1, 2, 3, 4]; + * var evens = _.remove(array, function(n) { + * return n % 2 == 0; + * }); + * + * console.log(array); + * // => [1, 3] + * + * console.log(evens); + * // => [2, 4] + */ + function remove(array, predicate, thisArg) { + var result = []; + if (!(array && array.length)) { + return result; + } + var index = -1, + indexes = [], + length = array.length; + + predicate = getCallback(predicate, thisArg, 3); + while (++index < length) { + var value = array[index]; + if (predicate(value, index, array)) { + result.push(value); + indexes.push(index); + } + } + basePullAt(array, indexes); + return result; + } + + /** + * Gets all but the first element of `array`. + * + * @static + * @memberOf _ + * @alias tail + * @category Array + * @param {Array} array The array to query. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.rest([1, 2, 3]); + * // => [2, 3] + */ + function rest(array) { + return drop(array, 1); + } + + /** + * Creates a slice of `array` from `start` up to, but not including, `end`. + * + * **Note:** This method is used instead of `Array#slice` to support node + * lists in IE < 9 and to ensure dense arrays are returned. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to slice. + * @param {number} [start=0] The start position. + * @param {number} [end=array.length] The end position. + * @returns {Array} Returns the slice of `array`. + */ + function slice(array, start, end) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (end && typeof end != 'number' && isIterateeCall(array, start, end)) { + start = 0; + end = length; + } + return baseSlice(array, start, end); + } + + /** + * Uses a binary search to determine the lowest index at which `value` should + * be inserted into `array` in order to maintain its sort order. If an iteratee + * function is provided it is invoked for `value` and each element of `array` + * to compute their sort ranking. The iteratee is bound to `thisArg` and + * invoked with one argument; (value). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + * @example + * + * _.sortedIndex([30, 50], 40); + * // => 1 + * + * _.sortedIndex([4, 4, 5, 5], 5); + * // => 2 + * + * var dict = { 'data': { 'thirty': 30, 'forty': 40, 'fifty': 50 } }; + * + * // using an iteratee function + * _.sortedIndex(['thirty', 'fifty'], 'forty', function(word) { + * return this.data[word]; + * }, dict); + * // => 1 + * + * // using the `_.property` callback shorthand + * _.sortedIndex([{ 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x'); + * // => 1 + */ + var sortedIndex = createSortedIndex(); + + /** + * This method is like `_.sortedIndex` except that it returns the highest + * index at which `value` should be inserted into `array` in order to + * maintain its sort order. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The sorted array to inspect. + * @param {*} value The value to evaluate. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {number} Returns the index at which `value` should be inserted + * into `array`. + * @example + * + * _.sortedLastIndex([4, 4, 5, 5], 5); + * // => 4 + */ + var sortedLastIndex = createSortedIndex(true); + + /** + * Creates a slice of `array` with `n` elements taken from the beginning. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to take. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.take([1, 2, 3]); + * // => [1] + * + * _.take([1, 2, 3], 2); + * // => [1, 2] + * + * _.take([1, 2, 3], 5); + * // => [1, 2, 3] + * + * _.take([1, 2, 3], 0); + * // => [] + */ + function take(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + return baseSlice(array, 0, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` with `n` elements taken from the end. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {number} [n=1] The number of elements to take. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.takeRight([1, 2, 3]); + * // => [3] + * + * _.takeRight([1, 2, 3], 2); + * // => [2, 3] + * + * _.takeRight([1, 2, 3], 5); + * // => [1, 2, 3] + * + * _.takeRight([1, 2, 3], 0); + * // => [] + */ + function takeRight(array, n, guard) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (guard ? isIterateeCall(array, n, guard) : n == null) { + n = 1; + } + n = length - (+n || 0); + return baseSlice(array, n < 0 ? 0 : n); + } + + /** + * Creates a slice of `array` with elements taken from the end. Elements are + * taken until `predicate` returns falsey. The predicate is bound to `thisArg` + * and invoked with three arguments: (value, index, array). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.takeRightWhile([1, 2, 3], function(n) { + * return n > 1; + * }); + * // => [2, 3] + * + * var users = [ + * { 'user': 'barney', 'active': true }, + * { 'user': 'fred', 'active': false }, + * { 'user': 'pebbles', 'active': false } + * ]; + * + * // using the `_.matches` callback shorthand + * _.pluck(_.takeRightWhile(users, { 'user': 'pebbles', 'active': false }), 'user'); + * // => ['pebbles'] + * + * // using the `_.matchesProperty` callback shorthand + * _.pluck(_.takeRightWhile(users, 'active', false), 'user'); + * // => ['fred', 'pebbles'] + * + * // using the `_.property` callback shorthand + * _.pluck(_.takeRightWhile(users, 'active'), 'user'); + * // => [] + */ + function takeRightWhile(array, predicate, thisArg) { + return (array && array.length) + ? baseWhile(array, getCallback(predicate, thisArg, 3), false, true) + : []; + } + + /** + * Creates a slice of `array` with elements taken from the beginning. Elements + * are taken until `predicate` returns falsey. The predicate is bound to + * `thisArg` and invoked with three arguments: (value, index, array). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to query. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the slice of `array`. + * @example + * + * _.takeWhile([1, 2, 3], function(n) { + * return n < 3; + * }); + * // => [1, 2] + * + * var users = [ + * { 'user': 'barney', 'active': false }, + * { 'user': 'fred', 'active': false}, + * { 'user': 'pebbles', 'active': true } + * ]; + * + * // using the `_.matches` callback shorthand + * _.pluck(_.takeWhile(users, { 'user': 'barney', 'active': false }), 'user'); + * // => ['barney'] + * + * // using the `_.matchesProperty` callback shorthand + * _.pluck(_.takeWhile(users, 'active', false), 'user'); + * // => ['barney', 'fred'] + * + * // using the `_.property` callback shorthand + * _.pluck(_.takeWhile(users, 'active'), 'user'); + * // => [] + */ + function takeWhile(array, predicate, thisArg) { + return (array && array.length) + ? baseWhile(array, getCallback(predicate, thisArg, 3)) + : []; + } + + /** + * Creates an array of unique values, in order, from all of the provided arrays + * using [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to inspect. + * @returns {Array} Returns the new array of combined values. + * @example + * + * _.union([1, 2], [4, 2], [2, 1]); + * // => [1, 2, 4] + */ + var union = restParam(function(arrays) { + return baseUniq(baseFlatten(arrays, false, true)); + }); + + /** + * Creates a duplicate-free version of an array, using + * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons, in which only the first occurence of each element + * is kept. Providing `true` for `isSorted` performs a faster search algorithm + * for sorted arrays. If an iteratee function is provided it is invoked for + * each element in the array to generate the criterion by which uniqueness + * is computed. The `iteratee` is bound to `thisArg` and invoked with three + * arguments: (value, index, array). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias unique + * @category Array + * @param {Array} array The array to inspect. + * @param {boolean} [isSorted] Specify the array is sorted. + * @param {Function|Object|string} [iteratee] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new duplicate-value-free array. + * @example + * + * _.uniq([2, 1, 2]); + * // => [2, 1] + * + * // using `isSorted` + * _.uniq([1, 1, 2], true); + * // => [1, 2] + * + * // using an iteratee function + * _.uniq([1, 2.5, 1.5, 2], function(n) { + * return this.floor(n); + * }, Math); + * // => [1, 2.5] + * + * // using the `_.property` callback shorthand + * _.uniq([{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }], 'x'); + * // => [{ 'x': 1 }, { 'x': 2 }] + */ + function uniq(array, isSorted, iteratee, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + if (isSorted != null && typeof isSorted != 'boolean') { + thisArg = iteratee; + iteratee = isIterateeCall(array, isSorted, thisArg) ? undefined : isSorted; + isSorted = false; + } + var callback = getCallback(); + if (!(iteratee == null && callback === baseCallback)) { + iteratee = callback(iteratee, thisArg, 3); + } + return (isSorted && getIndexOf() == baseIndexOf) + ? sortedUniq(array, iteratee) + : baseUniq(array, iteratee); + } + + /** + * This method is like `_.zip` except that it accepts an array of grouped + * elements and creates an array regrouping the elements to their pre-zip + * configuration. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array of grouped elements to process. + * @returns {Array} Returns the new array of regrouped elements. + * @example + * + * var zipped = _.zip(['fred', 'barney'], [30, 40], [true, false]); + * // => [['fred', 30, true], ['barney', 40, false]] + * + * _.unzip(zipped); + * // => [['fred', 'barney'], [30, 40], [true, false]] + */ + function unzip(array) { + if (!(array && array.length)) { + return []; + } + var index = -1, + length = 0; + + array = arrayFilter(array, function(group) { + if (isArrayLike(group)) { + length = nativeMax(group.length, length); + return true; + } + }); + var result = Array(length); + while (++index < length) { + result[index] = arrayMap(array, baseProperty(index)); + } + return result; + } + + /** + * This method is like `_.unzip` except that it accepts an iteratee to specify + * how regrouped values should be combined. The `iteratee` is bound to `thisArg` + * and invoked with four arguments: (accumulator, value, index, group). + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array of grouped elements to process. + * @param {Function} [iteratee] The function to combine regrouped values. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new array of regrouped elements. + * @example + * + * var zipped = _.zip([1, 2], [10, 20], [100, 200]); + * // => [[1, 10, 100], [2, 20, 200]] + * + * _.unzipWith(zipped, _.add); + * // => [3, 30, 300] + */ + function unzipWith(array, iteratee, thisArg) { + var length = array ? array.length : 0; + if (!length) { + return []; + } + var result = unzip(array); + if (iteratee == null) { + return result; + } + iteratee = bindCallback(iteratee, thisArg, 4); + return arrayMap(result, function(group) { + return arrayReduce(group, iteratee, undefined, true); + }); + } + + /** + * Creates an array excluding all provided values using + * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. + * + * @static + * @memberOf _ + * @category Array + * @param {Array} array The array to filter. + * @param {...*} [values] The values to exclude. + * @returns {Array} Returns the new array of filtered values. + * @example + * + * _.without([1, 2, 1, 3], 1, 2); + * // => [3] + */ + var without = restParam(function(array, values) { + return isArrayLike(array) + ? baseDifference(array, values) + : []; + }); + + /** + * Creates an array of unique values that is the [symmetric difference](https://en.wikipedia.org/wiki/Symmetric_difference) + * of the provided arrays. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to inspect. + * @returns {Array} Returns the new array of values. + * @example + * + * _.xor([1, 2], [4, 2]); + * // => [1, 4] + */ + function xor() { + var index = -1, + length = arguments.length; + + while (++index < length) { + var array = arguments[index]; + if (isArrayLike(array)) { + var result = result + ? arrayPush(baseDifference(result, array), baseDifference(array, result)) + : array; + } + } + return result ? baseUniq(result) : []; + } + + /** + * Creates an array of grouped elements, the first of which contains the first + * elements of the given arrays, the second of which contains the second elements + * of the given arrays, and so on. + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to process. + * @returns {Array} Returns the new array of grouped elements. + * @example + * + * _.zip(['fred', 'barney'], [30, 40], [true, false]); + * // => [['fred', 30, true], ['barney', 40, false]] + */ + var zip = restParam(unzip); + + /** + * The inverse of `_.pairs`; this method returns an object composed from arrays + * of property names and values. Provide either a single two dimensional array, + * e.g. `[[key1, value1], [key2, value2]]` or two arrays, one of property names + * and one of corresponding values. + * + * @static + * @memberOf _ + * @alias object + * @category Array + * @param {Array} props The property names. + * @param {Array} [values=[]] The property values. + * @returns {Object} Returns the new object. + * @example + * + * _.zipObject([['fred', 30], ['barney', 40]]); + * // => { 'fred': 30, 'barney': 40 } + * + * _.zipObject(['fred', 'barney'], [30, 40]); + * // => { 'fred': 30, 'barney': 40 } + */ + function zipObject(props, values) { + var index = -1, + length = props ? props.length : 0, + result = {}; + + if (length && !values && !isArray(props[0])) { + values = []; + } + while (++index < length) { + var key = props[index]; + if (values) { + result[key] = values[index]; + } else if (key) { + result[key[0]] = key[1]; + } + } + return result; + } + + /** + * This method is like `_.zip` except that it accepts an iteratee to specify + * how grouped values should be combined. The `iteratee` is bound to `thisArg` + * and invoked with four arguments: (accumulator, value, index, group). + * + * @static + * @memberOf _ + * @category Array + * @param {...Array} [arrays] The arrays to process. + * @param {Function} [iteratee] The function to combine grouped values. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new array of grouped elements. + * @example + * + * _.zipWith([1, 2], [10, 20], [100, 200], _.add); + * // => [111, 222] + */ + var zipWith = restParam(function(arrays) { + var length = arrays.length, + iteratee = length > 2 ? arrays[length - 2] : undefined, + thisArg = length > 1 ? arrays[length - 1] : undefined; + + if (length > 2 && typeof iteratee == 'function') { + length -= 2; + } else { + iteratee = (length > 1 && typeof thisArg == 'function') ? (--length, thisArg) : undefined; + thisArg = undefined; + } + arrays.length = length; + return unzipWith(arrays, iteratee, thisArg); + }); + + /*------------------------------------------------------------------------*/ + + /** + * Creates a `lodash` object that wraps `value` with explicit method + * chaining enabled. + * + * @static + * @memberOf _ + * @category Chain + * @param {*} value The value to wrap. + * @returns {Object} Returns the new `lodash` wrapper instance. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 }, + * { 'user': 'pebbles', 'age': 1 } + * ]; + * + * var youngest = _.chain(users) + * .sortBy('age') + * .map(function(chr) { + * return chr.user + ' is ' + chr.age; + * }) + * .first() + * .value(); + * // => 'pebbles is 1' + */ + function chain(value) { + var result = lodash(value); + result.__chain__ = true; + return result; + } + + /** + * This method invokes `interceptor` and returns `value`. The interceptor is + * bound to `thisArg` and invoked with one argument; (value). The purpose of + * this method is to "tap into" a method chain in order to perform operations + * on intermediate results within the chain. + * + * @static + * @memberOf _ + * @category Chain + * @param {*} value The value to provide to `interceptor`. + * @param {Function} interceptor The function to invoke. + * @param {*} [thisArg] The `this` binding of `interceptor`. + * @returns {*} Returns `value`. + * @example + * + * _([1, 2, 3]) + * .tap(function(array) { + * array.pop(); + * }) + * .reverse() + * .value(); + * // => [2, 1] + */ + function tap(value, interceptor, thisArg) { + interceptor.call(thisArg, value); + return value; + } + + /** + * This method is like `_.tap` except that it returns the result of `interceptor`. + * + * @static + * @memberOf _ + * @category Chain + * @param {*} value The value to provide to `interceptor`. + * @param {Function} interceptor The function to invoke. + * @param {*} [thisArg] The `this` binding of `interceptor`. + * @returns {*} Returns the result of `interceptor`. + * @example + * + * _(' abc ') + * .chain() + * .trim() + * .thru(function(value) { + * return [value]; + * }) + * .value(); + * // => ['abc'] + */ + function thru(value, interceptor, thisArg) { + return interceptor.call(thisArg, value); + } + + /** + * Enables explicit method chaining on the wrapper object. + * + * @name chain + * @memberOf _ + * @category Chain + * @returns {Object} Returns the new `lodash` wrapper instance. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * // without explicit chaining + * _(users).first(); + * // => { 'user': 'barney', 'age': 36 } + * + * // with explicit chaining + * _(users).chain() + * .first() + * .pick('user') + * .value(); + * // => { 'user': 'barney' } + */ + function wrapperChain() { + return chain(this); + } + + /** + * Executes the chained sequence and returns the wrapped result. + * + * @name commit + * @memberOf _ + * @category Chain + * @returns {Object} Returns the new `lodash` wrapper instance. + * @example + * + * var array = [1, 2]; + * var wrapped = _(array).push(3); + * + * console.log(array); + * // => [1, 2] + * + * wrapped = wrapped.commit(); + * console.log(array); + * // => [1, 2, 3] + * + * wrapped.last(); + * // => 3 + * + * console.log(array); + * // => [1, 2, 3] + */ + function wrapperCommit() { + return new LodashWrapper(this.value(), this.__chain__); + } + + /** + * Creates a new array joining a wrapped array with any additional arrays + * and/or values. + * + * @name concat + * @memberOf _ + * @category Chain + * @param {...*} [values] The values to concatenate. + * @returns {Array} Returns the new concatenated array. + * @example + * + * var array = [1]; + * var wrapped = _(array).concat(2, [3], [[4]]); + * + * console.log(wrapped.value()); + * // => [1, 2, 3, [4]] + * + * console.log(array); + * // => [1] + */ + var wrapperConcat = restParam(function(values) { + values = baseFlatten(values); + return this.thru(function(array) { + return arrayConcat(isArray(array) ? array : [toObject(array)], values); + }); + }); + + /** + * Creates a clone of the chained sequence planting `value` as the wrapped value. + * + * @name plant + * @memberOf _ + * @category Chain + * @returns {Object} Returns the new `lodash` wrapper instance. + * @example + * + * var array = [1, 2]; + * var wrapped = _(array).map(function(value) { + * return Math.pow(value, 2); + * }); + * + * var other = [3, 4]; + * var otherWrapped = wrapped.plant(other); + * + * otherWrapped.value(); + * // => [9, 16] + * + * wrapped.value(); + * // => [1, 4] + */ + function wrapperPlant(value) { + var result, + parent = this; + + while (parent instanceof baseLodash) { + var clone = wrapperClone(parent); + if (result) { + previous.__wrapped__ = clone; + } else { + result = clone; + } + var previous = clone; + parent = parent.__wrapped__; + } + previous.__wrapped__ = value; + return result; + } + + /** + * Reverses the wrapped array so the first element becomes the last, the + * second element becomes the second to last, and so on. + * + * **Note:** This method mutates the wrapped array. + * + * @name reverse + * @memberOf _ + * @category Chain + * @returns {Object} Returns the new reversed `lodash` wrapper instance. + * @example + * + * var array = [1, 2, 3]; + * + * _(array).reverse().value() + * // => [3, 2, 1] + * + * console.log(array); + * // => [3, 2, 1] + */ + function wrapperReverse() { + var value = this.__wrapped__; + + var interceptor = function(value) { + return (wrapped && wrapped.__dir__ < 0) ? value : value.reverse(); + }; + if (value instanceof LazyWrapper) { + var wrapped = value; + if (this.__actions__.length) { + wrapped = new LazyWrapper(this); + } + wrapped = wrapped.reverse(); + wrapped.__actions__.push({ 'func': thru, 'args': [interceptor], 'thisArg': undefined }); + return new LodashWrapper(wrapped, this.__chain__); + } + return this.thru(interceptor); + } + + /** + * Produces the result of coercing the unwrapped value to a string. + * + * @name toString + * @memberOf _ + * @category Chain + * @returns {string} Returns the coerced string value. + * @example + * + * _([1, 2, 3]).toString(); + * // => '1,2,3' + */ + function wrapperToString() { + return (this.value() + ''); + } + + /** + * Executes the chained sequence to extract the unwrapped value. + * + * @name value + * @memberOf _ + * @alias run, toJSON, valueOf + * @category Chain + * @returns {*} Returns the resolved unwrapped value. + * @example + * + * _([1, 2, 3]).value(); + * // => [1, 2, 3] + */ + function wrapperValue() { + return baseWrapperValue(this.__wrapped__, this.__actions__); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates an array of elements corresponding to the given keys, or indexes, + * of `collection`. Keys may be specified as individual arguments or as arrays + * of keys. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {...(number|number[]|string|string[])} [props] The property names + * or indexes of elements to pick, specified individually or in arrays. + * @returns {Array} Returns the new array of picked elements. + * @example + * + * _.at(['a', 'b', 'c'], [0, 2]); + * // => ['a', 'c'] + * + * _.at(['barney', 'fred', 'pebbles'], 0, 2); + * // => ['barney', 'pebbles'] + */ + var at = restParam(function(collection, props) { + return baseAt(collection, baseFlatten(props)); + }); + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through `iteratee`. The corresponding value + * of each key is the number of times the key was returned by `iteratee`. + * The `iteratee` is bound to `thisArg` and invoked with three arguments: + * (value, index|key, collection). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.countBy([4.3, 6.1, 6.4], function(n) { + * return Math.floor(n); + * }); + * // => { '4': 1, '6': 2 } + * + * _.countBy([4.3, 6.1, 6.4], function(n) { + * return this.floor(n); + * }, Math); + * // => { '4': 1, '6': 2 } + * + * _.countBy(['one', 'two', 'three'], 'length'); + * // => { '3': 2, '5': 1 } + */ + var countBy = createAggregator(function(result, value, key) { + hasOwnProperty.call(result, key) ? ++result[key] : (result[key] = 1); + }); + + /** + * Checks if `predicate` returns truthy for **all** elements of `collection`. + * The predicate is bound to `thisArg` and invoked with three arguments: + * (value, index|key, collection). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias all + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {boolean} Returns `true` if all elements pass the predicate check, + * else `false`. + * @example + * + * _.every([true, 1, null, 'yes'], Boolean); + * // => false + * + * var users = [ + * { 'user': 'barney', 'active': false }, + * { 'user': 'fred', 'active': false } + * ]; + * + * // using the `_.matches` callback shorthand + * _.every(users, { 'user': 'barney', 'active': false }); + * // => false + * + * // using the `_.matchesProperty` callback shorthand + * _.every(users, 'active', false); + * // => true + * + * // using the `_.property` callback shorthand + * _.every(users, 'active'); + * // => false + */ + function every(collection, predicate, thisArg) { + var func = isArray(collection) ? arrayEvery : baseEvery; + if (thisArg && isIterateeCall(collection, predicate, thisArg)) { + predicate = undefined; + } + if (typeof predicate != 'function' || thisArg !== undefined) { + predicate = getCallback(predicate, thisArg, 3); + } + return func(collection, predicate); + } + + /** + * Iterates over elements of `collection`, returning an array of all elements + * `predicate` returns truthy for. The predicate is bound to `thisArg` and + * invoked with three arguments: (value, index|key, collection). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias select + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the new filtered array. + * @example + * + * _.filter([4, 5, 6], function(n) { + * return n % 2 == 0; + * }); + * // => [4, 6] + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': true }, + * { 'user': 'fred', 'age': 40, 'active': false } + * ]; + * + * // using the `_.matches` callback shorthand + * _.pluck(_.filter(users, { 'age': 36, 'active': true }), 'user'); + * // => ['barney'] + * + * // using the `_.matchesProperty` callback shorthand + * _.pluck(_.filter(users, 'active', false), 'user'); + * // => ['fred'] + * + * // using the `_.property` callback shorthand + * _.pluck(_.filter(users, 'active'), 'user'); + * // => ['barney'] + */ + function filter(collection, predicate, thisArg) { + var func = isArray(collection) ? arrayFilter : baseFilter; + predicate = getCallback(predicate, thisArg, 3); + return func(collection, predicate); + } + + /** + * Iterates over elements of `collection`, returning the first element + * `predicate` returns truthy for. The predicate is bound to `thisArg` and + * invoked with three arguments: (value, index|key, collection). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias detect + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {*} Returns the matched element, else `undefined`. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': true }, + * { 'user': 'fred', 'age': 40, 'active': false }, + * { 'user': 'pebbles', 'age': 1, 'active': true } + * ]; + * + * _.result(_.find(users, function(chr) { + * return chr.age < 40; + * }), 'user'); + * // => 'barney' + * + * // using the `_.matches` callback shorthand + * _.result(_.find(users, { 'age': 1, 'active': true }), 'user'); + * // => 'pebbles' + * + * // using the `_.matchesProperty` callback shorthand + * _.result(_.find(users, 'active', false), 'user'); + * // => 'fred' + * + * // using the `_.property` callback shorthand + * _.result(_.find(users, 'active'), 'user'); + * // => 'barney' + */ + var find = createFind(baseEach); + + /** + * This method is like `_.find` except that it iterates over elements of + * `collection` from right to left. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {*} Returns the matched element, else `undefined`. + * @example + * + * _.findLast([1, 2, 3, 4], function(n) { + * return n % 2 == 1; + * }); + * // => 3 + */ + var findLast = createFind(baseEachRight, true); + + /** + * Performs a deep comparison between each element in `collection` and the + * source object, returning the first element that has equivalent property + * values. + * + * **Note:** This method supports comparing arrays, booleans, `Date` objects, + * numbers, `Object` objects, regexes, and strings. Objects are compared by + * their own, not inherited, enumerable properties. For comparing a single + * own or inherited property value see `_.matchesProperty`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Object} source The object of property values to match. + * @returns {*} Returns the matched element, else `undefined`. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': true }, + * { 'user': 'fred', 'age': 40, 'active': false } + * ]; + * + * _.result(_.findWhere(users, { 'age': 36, 'active': true }), 'user'); + * // => 'barney' + * + * _.result(_.findWhere(users, { 'age': 40, 'active': false }), 'user'); + * // => 'fred' + */ + function findWhere(collection, source) { + return find(collection, baseMatches(source)); + } + + /** + * Iterates over elements of `collection` invoking `iteratee` for each element. + * The `iteratee` is bound to `thisArg` and invoked with three arguments: + * (value, index|key, collection). Iteratee functions may exit iteration early + * by explicitly returning `false`. + * + * **Note:** As with other "Collections" methods, objects with a "length" property + * are iterated like arrays. To avoid this behavior `_.forIn` or `_.forOwn` + * may be used for object iteration. + * + * @static + * @memberOf _ + * @alias each + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array|Object|string} Returns `collection`. + * @example + * + * _([1, 2]).forEach(function(n) { + * console.log(n); + * }).value(); + * // => logs each value from left to right and returns the array + * + * _.forEach({ 'a': 1, 'b': 2 }, function(n, key) { + * console.log(n, key); + * }); + * // => logs each value-key pair and returns the object (iteration order is not guaranteed) + */ + var forEach = createForEach(arrayEach, baseEach); + + /** + * This method is like `_.forEach` except that it iterates over elements of + * `collection` from right to left. + * + * @static + * @memberOf _ + * @alias eachRight + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array|Object|string} Returns `collection`. + * @example + * + * _([1, 2]).forEachRight(function(n) { + * console.log(n); + * }).value(); + * // => logs each value from right to left and returns the array + */ + var forEachRight = createForEach(arrayEachRight, baseEachRight); + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through `iteratee`. The corresponding value + * of each key is an array of the elements responsible for generating the key. + * The `iteratee` is bound to `thisArg` and invoked with three arguments: + * (value, index|key, collection). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * _.groupBy([4.2, 6.1, 6.4], function(n) { + * return Math.floor(n); + * }); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * _.groupBy([4.2, 6.1, 6.4], function(n) { + * return this.floor(n); + * }, Math); + * // => { '4': [4.2], '6': [6.1, 6.4] } + * + * // using the `_.property` callback shorthand + * _.groupBy(['one', 'two', 'three'], 'length'); + * // => { '3': ['one', 'two'], '5': ['three'] } + */ + var groupBy = createAggregator(function(result, value, key) { + if (hasOwnProperty.call(result, key)) { + result[key].push(value); + } else { + result[key] = [value]; + } + }); + + /** + * Checks if `value` is in `collection` using + * [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero) + * for equality comparisons. If `fromIndex` is negative, it is used as the offset + * from the end of `collection`. + * + * @static + * @memberOf _ + * @alias contains, include + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {*} target The value to search for. + * @param {number} [fromIndex=0] The index to search from. + * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`. + * @returns {boolean} Returns `true` if a matching element is found, else `false`. + * @example + * + * _.includes([1, 2, 3], 1); + * // => true + * + * _.includes([1, 2, 3], 1, 2); + * // => false + * + * _.includes({ 'user': 'fred', 'age': 40 }, 'fred'); + * // => true + * + * _.includes('pebbles', 'eb'); + * // => true + */ + function includes(collection, target, fromIndex, guard) { + var length = collection ? getLength(collection) : 0; + if (!isLength(length)) { + collection = values(collection); + length = collection.length; + } + if (typeof fromIndex != 'number' || (guard && isIterateeCall(target, fromIndex, guard))) { + fromIndex = 0; + } else { + fromIndex = fromIndex < 0 ? nativeMax(length + fromIndex, 0) : (fromIndex || 0); + } + return (typeof collection == 'string' || !isArray(collection) && isString(collection)) + ? (fromIndex <= length && collection.indexOf(target, fromIndex) > -1) + : (!!length && getIndexOf(collection, target, fromIndex) > -1); + } + + /** + * Creates an object composed of keys generated from the results of running + * each element of `collection` through `iteratee`. The corresponding value + * of each key is the last element responsible for generating the key. The + * iteratee function is bound to `thisArg` and invoked with three arguments: + * (value, index|key, collection). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the composed aggregate object. + * @example + * + * var keyData = [ + * { 'dir': 'left', 'code': 97 }, + * { 'dir': 'right', 'code': 100 } + * ]; + * + * _.indexBy(keyData, 'dir'); + * // => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } } + * + * _.indexBy(keyData, function(object) { + * return String.fromCharCode(object.code); + * }); + * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } + * + * _.indexBy(keyData, function(object) { + * return this.fromCharCode(object.code); + * }, String); + * // => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } } + */ + var indexBy = createAggregator(function(result, value, key) { + result[key] = value; + }); + + /** + * Invokes the method at `path` of each element in `collection`, returning + * an array of the results of each invoked method. Any additional arguments + * are provided to each invoked method. If `methodName` is a function it is + * invoked for, and `this` bound to, each element in `collection`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Array|Function|string} path The path of the method to invoke or + * the function invoked per iteration. + * @param {...*} [args] The arguments to invoke the method with. + * @returns {Array} Returns the array of results. + * @example + * + * _.invoke([[5, 1, 7], [3, 2, 1]], 'sort'); + * // => [[1, 5, 7], [1, 2, 3]] + * + * _.invoke([123, 456], String.prototype.split, ''); + * // => [['1', '2', '3'], ['4', '5', '6']] + */ + var invoke = restParam(function(collection, path, args) { + var index = -1, + isFunc = typeof path == 'function', + isProp = isKey(path), + result = isArrayLike(collection) ? Array(collection.length) : []; + + baseEach(collection, function(value) { + var func = isFunc ? path : ((isProp && value != null) ? value[path] : undefined); + result[++index] = func ? func.apply(value, args) : invokePath(value, path, args); + }); + return result; + }); + + /** + * Creates an array of values by running each element in `collection` through + * `iteratee`. The `iteratee` is bound to `thisArg` and invoked with three + * arguments: (value, index|key, collection). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * Many lodash methods are guarded to work as iteratees for methods like + * `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`. + * + * The guarded methods are: + * `ary`, `callback`, `chunk`, `clone`, `create`, `curry`, `curryRight`, + * `drop`, `dropRight`, `every`, `fill`, `flatten`, `invert`, `max`, `min`, + * `parseInt`, `slice`, `sortBy`, `take`, `takeRight`, `template`, `trim`, + * `trimLeft`, `trimRight`, `trunc`, `random`, `range`, `sample`, `some`, + * `sum`, `uniq`, and `words` + * + * @static + * @memberOf _ + * @alias collect + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new mapped array. + * @example + * + * function timesThree(n) { + * return n * 3; + * } + * + * _.map([1, 2], timesThree); + * // => [3, 6] + * + * _.map({ 'a': 1, 'b': 2 }, timesThree); + * // => [3, 6] (iteration order is not guaranteed) + * + * var users = [ + * { 'user': 'barney' }, + * { 'user': 'fred' } + * ]; + * + * // using the `_.property` callback shorthand + * _.map(users, 'user'); + * // => ['barney', 'fred'] + */ + function map(collection, iteratee, thisArg) { + var func = isArray(collection) ? arrayMap : baseMap; + iteratee = getCallback(iteratee, thisArg, 3); + return func(collection, iteratee); + } + + /** + * Creates an array of elements split into two groups, the first of which + * contains elements `predicate` returns truthy for, while the second of which + * contains elements `predicate` returns falsey for. The predicate is bound + * to `thisArg` and invoked with three arguments: (value, index|key, collection). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the array of grouped elements. + * @example + * + * _.partition([1, 2, 3], function(n) { + * return n % 2; + * }); + * // => [[1, 3], [2]] + * + * _.partition([1.2, 2.3, 3.4], function(n) { + * return this.floor(n) % 2; + * }, Math); + * // => [[1.2, 3.4], [2.3]] + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true }, + * { 'user': 'pebbles', 'age': 1, 'active': false } + * ]; + * + * var mapper = function(array) { + * return _.pluck(array, 'user'); + * }; + * + * // using the `_.matches` callback shorthand + * _.map(_.partition(users, { 'age': 1, 'active': false }), mapper); + * // => [['pebbles'], ['barney', 'fred']] + * + * // using the `_.matchesProperty` callback shorthand + * _.map(_.partition(users, 'active', false), mapper); + * // => [['barney', 'pebbles'], ['fred']] + * + * // using the `_.property` callback shorthand + * _.map(_.partition(users, 'active'), mapper); + * // => [['fred'], ['barney', 'pebbles']] + */ + var partition = createAggregator(function(result, value, key) { + result[key ? 0 : 1].push(value); + }, function() { return [[], []]; }); + + /** + * Gets the property value of `path` from all elements in `collection`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Array|string} path The path of the property to pluck. + * @returns {Array} Returns the property values. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 40 } + * ]; + * + * _.pluck(users, 'user'); + * // => ['barney', 'fred'] + * + * var userIndex = _.indexBy(users, 'user'); + * _.pluck(userIndex, 'age'); + * // => [36, 40] (iteration order is not guaranteed) + */ + function pluck(collection, path) { + return map(collection, property(path)); + } + + /** + * Reduces `collection` to a value which is the accumulated result of running + * each element in `collection` through `iteratee`, where each successive + * invocation is supplied the return value of the previous. If `accumulator` + * is not provided the first element of `collection` is used as the initial + * value. The `iteratee` is bound to `thisArg` and invoked with four arguments: + * (accumulator, value, index|key, collection). + * + * Many lodash methods are guarded to work as iteratees for methods like + * `_.reduce`, `_.reduceRight`, and `_.transform`. + * + * The guarded methods are: + * `assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `sortByAll`, + * and `sortByOrder` + * + * @static + * @memberOf _ + * @alias foldl, inject + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the accumulated value. + * @example + * + * _.reduce([1, 2], function(total, n) { + * return total + n; + * }); + * // => 3 + * + * _.reduce({ 'a': 1, 'b': 2 }, function(result, n, key) { + * result[key] = n * 3; + * return result; + * }, {}); + * // => { 'a': 3, 'b': 6 } (iteration order is not guaranteed) + */ + var reduce = createReduce(arrayReduce, baseEach); + + /** + * This method is like `_.reduce` except that it iterates over elements of + * `collection` from right to left. + * + * @static + * @memberOf _ + * @alias foldr + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The initial value. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the accumulated value. + * @example + * + * var array = [[0, 1], [2, 3], [4, 5]]; + * + * _.reduceRight(array, function(flattened, other) { + * return flattened.concat(other); + * }, []); + * // => [4, 5, 2, 3, 0, 1] + */ + var reduceRight = createReduce(arrayReduceRight, baseEachRight); + + /** + * The opposite of `_.filter`; this method returns the elements of `collection` + * that `predicate` does **not** return truthy for. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Array} Returns the new filtered array. + * @example + * + * _.reject([1, 2, 3, 4], function(n) { + * return n % 2 == 0; + * }); + * // => [1, 3] + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false }, + * { 'user': 'fred', 'age': 40, 'active': true } + * ]; + * + * // using the `_.matches` callback shorthand + * _.pluck(_.reject(users, { 'age': 40, 'active': true }), 'user'); + * // => ['barney'] + * + * // using the `_.matchesProperty` callback shorthand + * _.pluck(_.reject(users, 'active', false), 'user'); + * // => ['fred'] + * + * // using the `_.property` callback shorthand + * _.pluck(_.reject(users, 'active'), 'user'); + * // => ['barney'] + */ + function reject(collection, predicate, thisArg) { + var func = isArray(collection) ? arrayFilter : baseFilter; + predicate = getCallback(predicate, thisArg, 3); + return func(collection, function(value, index, collection) { + return !predicate(value, index, collection); + }); + } + + /** + * Gets a random element or `n` random elements from a collection. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to sample. + * @param {number} [n] The number of elements to sample. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {*} Returns the random sample(s). + * @example + * + * _.sample([1, 2, 3, 4]); + * // => 2 + * + * _.sample([1, 2, 3, 4], 2); + * // => [3, 1] + */ + function sample(collection, n, guard) { + if (guard ? isIterateeCall(collection, n, guard) : n == null) { + collection = toIterable(collection); + var length = collection.length; + return length > 0 ? collection[baseRandom(0, length - 1)] : undefined; + } + var index = -1, + result = toArray(collection), + length = result.length, + lastIndex = length - 1; + + n = nativeMin(n < 0 ? 0 : (+n || 0), length); + while (++index < n) { + var rand = baseRandom(index, lastIndex), + value = result[rand]; + + result[rand] = result[index]; + result[index] = value; + } + result.length = n; + return result; + } + + /** + * Creates an array of shuffled values, using a version of the + * [Fisher-Yates shuffle](https://en.wikipedia.org/wiki/Fisher-Yates_shuffle). + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to shuffle. + * @returns {Array} Returns the new shuffled array. + * @example + * + * _.shuffle([1, 2, 3, 4]); + * // => [4, 1, 3, 2] + */ + function shuffle(collection) { + return sample(collection, POSITIVE_INFINITY); + } + + /** + * Gets the size of `collection` by returning its length for array-like + * values or the number of own enumerable properties for objects. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to inspect. + * @returns {number} Returns the size of `collection`. + * @example + * + * _.size([1, 2, 3]); + * // => 3 + * + * _.size({ 'a': 1, 'b': 2 }); + * // => 2 + * + * _.size('pebbles'); + * // => 7 + */ + function size(collection) { + var length = collection ? getLength(collection) : 0; + return isLength(length) ? length : keys(collection).length; + } + + /** + * Checks if `predicate` returns truthy for **any** element of `collection`. + * The function returns as soon as it finds a passing value and does not iterate + * over the entire collection. The predicate is bound to `thisArg` and invoked + * with three arguments: (value, index|key, collection). + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @alias any + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {boolean} Returns `true` if any element passes the predicate check, + * else `false`. + * @example + * + * _.some([null, 0, 'yes', false], Boolean); + * // => true + * + * var users = [ + * { 'user': 'barney', 'active': true }, + * { 'user': 'fred', 'active': false } + * ]; + * + * // using the `_.matches` callback shorthand + * _.some(users, { 'user': 'barney', 'active': false }); + * // => false + * + * // using the `_.matchesProperty` callback shorthand + * _.some(users, 'active', false); + * // => true + * + * // using the `_.property` callback shorthand + * _.some(users, 'active'); + * // => true + */ + function some(collection, predicate, thisArg) { + var func = isArray(collection) ? arraySome : baseSome; + if (thisArg && isIterateeCall(collection, predicate, thisArg)) { + predicate = undefined; + } + if (typeof predicate != 'function' || thisArg !== undefined) { + predicate = getCallback(predicate, thisArg, 3); + } + return func(collection, predicate); + } + + /** + * Creates an array of elements, sorted in ascending order by the results of + * running each element in a collection through `iteratee`. This method performs + * a stable sort, that is, it preserves the original sort order of equal elements. + * The `iteratee` is bound to `thisArg` and invoked with three arguments: + * (value, index|key, collection). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Array} Returns the new sorted array. + * @example + * + * _.sortBy([1, 2, 3], function(n) { + * return Math.sin(n); + * }); + * // => [3, 1, 2] + * + * _.sortBy([1, 2, 3], function(n) { + * return this.sin(n); + * }, Math); + * // => [3, 1, 2] + * + * var users = [ + * { 'user': 'fred' }, + * { 'user': 'pebbles' }, + * { 'user': 'barney' } + * ]; + * + * // using the `_.property` callback shorthand + * _.pluck(_.sortBy(users, 'user'), 'user'); + * // => ['barney', 'fred', 'pebbles'] + */ + function sortBy(collection, iteratee, thisArg) { + if (collection == null) { + return []; + } + if (thisArg && isIterateeCall(collection, iteratee, thisArg)) { + iteratee = undefined; + } + var index = -1; + iteratee = getCallback(iteratee, thisArg, 3); + + var result = baseMap(collection, function(value, key, collection) { + return { 'criteria': iteratee(value, key, collection), 'index': ++index, 'value': value }; + }); + return baseSortBy(result, compareAscending); + } + + /** + * This method is like `_.sortBy` except that it can sort by multiple iteratees + * or property names. + * + * If a property name is provided for an iteratee the created `_.property` + * style callback returns the property value of the given element. + * + * If an object is provided for an iteratee the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {...(Function|Function[]|Object|Object[]|string|string[])} iteratees + * The iteratees to sort by, specified as individual values or arrays of values. + * @returns {Array} Returns the new sorted array. + * @example + * + * var users = [ + * { 'user': 'fred', 'age': 48 }, + * { 'user': 'barney', 'age': 36 }, + * { 'user': 'fred', 'age': 42 }, + * { 'user': 'barney', 'age': 34 } + * ]; + * + * _.map(_.sortByAll(users, ['user', 'age']), _.values); + * // => [['barney', 34], ['barney', 36], ['fred', 42], ['fred', 48]] + * + * _.map(_.sortByAll(users, 'user', function(chr) { + * return Math.floor(chr.age / 10); + * }), _.values); + * // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]] + */ + var sortByAll = restParam(function(collection, iteratees) { + if (collection == null) { + return []; + } + var guard = iteratees[2]; + if (guard && isIterateeCall(iteratees[0], iteratees[1], guard)) { + iteratees.length = 1; + } + return baseSortByOrder(collection, baseFlatten(iteratees), []); + }); + + /** + * This method is like `_.sortByAll` except that it allows specifying the + * sort orders of the iteratees to sort by. If `orders` is unspecified, all + * values are sorted in ascending order. Otherwise, a value is sorted in + * ascending order if its corresponding order is "asc", and descending if "desc". + * + * If a property name is provided for an iteratee the created `_.property` + * style callback returns the property value of the given element. + * + * If an object is provided for an iteratee the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to iterate over. + * @param {Function[]|Object[]|string[]} iteratees The iteratees to sort by. + * @param {boolean[]} [orders] The sort orders of `iteratees`. + * @param- {Object} [guard] Enables use as a callback for functions like `_.reduce`. + * @returns {Array} Returns the new sorted array. + * @example + * + * var users = [ + * { 'user': 'fred', 'age': 48 }, + * { 'user': 'barney', 'age': 34 }, + * { 'user': 'fred', 'age': 42 }, + * { 'user': 'barney', 'age': 36 } + * ]; + * + * // sort by `user` in ascending order and by `age` in descending order + * _.map(_.sortByOrder(users, ['user', 'age'], ['asc', 'desc']), _.values); + * // => [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 42]] + */ + function sortByOrder(collection, iteratees, orders, guard) { + if (collection == null) { + return []; + } + if (guard && isIterateeCall(iteratees, orders, guard)) { + orders = undefined; + } + if (!isArray(iteratees)) { + iteratees = iteratees == null ? [] : [iteratees]; + } + if (!isArray(orders)) { + orders = orders == null ? [] : [orders]; + } + return baseSortByOrder(collection, iteratees, orders); + } + + /** + * Performs a deep comparison between each element in `collection` and the + * source object, returning an array of all elements that have equivalent + * property values. + * + * **Note:** This method supports comparing arrays, booleans, `Date` objects, + * numbers, `Object` objects, regexes, and strings. Objects are compared by + * their own, not inherited, enumerable properties. For comparing a single + * own or inherited property value see `_.matchesProperty`. + * + * @static + * @memberOf _ + * @category Collection + * @param {Array|Object|string} collection The collection to search. + * @param {Object} source The object of property values to match. + * @returns {Array} Returns the new filtered array. + * @example + * + * var users = [ + * { 'user': 'barney', 'age': 36, 'active': false, 'pets': ['hoppy'] }, + * { 'user': 'fred', 'age': 40, 'active': true, 'pets': ['baby puss', 'dino'] } + * ]; + * + * _.pluck(_.where(users, { 'age': 36, 'active': false }), 'user'); + * // => ['barney'] + * + * _.pluck(_.where(users, { 'pets': ['dino'] }), 'user'); + * // => ['fred'] + */ + function where(collection, source) { + return filter(collection, baseMatches(source)); + } + + /*------------------------------------------------------------------------*/ + + /** + * Gets the number of milliseconds that have elapsed since the Unix epoch + * (1 January 1970 00:00:00 UTC). + * + * @static + * @memberOf _ + * @category Date + * @example + * + * _.defer(function(stamp) { + * console.log(_.now() - stamp); + * }, _.now()); + * // => logs the number of milliseconds it took for the deferred function to be invoked + */ + var now = nativeNow || function() { + return new Date().getTime(); + }; + + /*------------------------------------------------------------------------*/ + + /** + * The opposite of `_.before`; this method creates a function that invokes + * `func` once it is called `n` or more times. + * + * @static + * @memberOf _ + * @category Function + * @param {number} n The number of calls before `func` is invoked. + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * var saves = ['profile', 'settings']; + * + * var done = _.after(saves.length, function() { + * console.log('done saving!'); + * }); + * + * _.forEach(saves, function(type) { + * asyncSave({ 'type': type, 'complete': done }); + * }); + * // => logs 'done saving!' after the two async saves have completed + */ + function after(n, func) { + if (typeof func != 'function') { + if (typeof n == 'function') { + var temp = n; + n = func; + func = temp; + } else { + throw new TypeError(FUNC_ERROR_TEXT); + } + } + n = nativeIsFinite(n = +n) ? n : 0; + return function() { + if (--n < 1) { + return func.apply(this, arguments); + } + }; + } + + /** + * Creates a function that accepts up to `n` arguments ignoring any + * additional arguments. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to cap arguments for. + * @param {number} [n=func.length] The arity cap. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Function} Returns the new function. + * @example + * + * _.map(['6', '8', '10'], _.ary(parseInt, 1)); + * // => [6, 8, 10] + */ + function ary(func, n, guard) { + if (guard && isIterateeCall(func, n, guard)) { + n = undefined; + } + n = (func && n == null) ? func.length : nativeMax(+n || 0, 0); + return createWrapper(func, ARY_FLAG, undefined, undefined, undefined, undefined, n); + } + + /** + * Creates a function that invokes `func`, with the `this` binding and arguments + * of the created function, while it is called less than `n` times. Subsequent + * calls to the created function return the result of the last `func` invocation. + * + * @static + * @memberOf _ + * @category Function + * @param {number} n The number of calls at which `func` is no longer invoked. + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * jQuery('#add').on('click', _.before(5, addContactToList)); + * // => allows adding up to 4 contacts to the list + */ + function before(n, func) { + var result; + if (typeof func != 'function') { + if (typeof n == 'function') { + var temp = n; + n = func; + func = temp; + } else { + throw new TypeError(FUNC_ERROR_TEXT); + } + } + return function() { + if (--n > 0) { + result = func.apply(this, arguments); + } + if (n <= 1) { + func = undefined; + } + return result; + }; + } + + /** + * Creates a function that invokes `func` with the `this` binding of `thisArg` + * and prepends any additional `_.bind` arguments to those provided to the + * bound function. + * + * The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, + * may be used as a placeholder for partially applied arguments. + * + * **Note:** Unlike native `Function#bind` this method does not set the "length" + * property of bound functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to bind. + * @param {*} thisArg The `this` binding of `func`. + * @param {...*} [partials] The arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var greet = function(greeting, punctuation) { + * return greeting + ' ' + this.user + punctuation; + * }; + * + * var object = { 'user': 'fred' }; + * + * var bound = _.bind(greet, object, 'hi'); + * bound('!'); + * // => 'hi fred!' + * + * // using placeholders + * var bound = _.bind(greet, object, _, '!'); + * bound('hi'); + * // => 'hi fred!' + */ + var bind = restParam(function(func, thisArg, partials) { + var bitmask = BIND_FLAG; + if (partials.length) { + var holders = replaceHolders(partials, bind.placeholder); + bitmask |= PARTIAL_FLAG; + } + return createWrapper(func, bitmask, thisArg, partials, holders); + }); + + /** + * Binds methods of an object to the object itself, overwriting the existing + * method. Method names may be specified as individual arguments or as arrays + * of method names. If no method names are provided all enumerable function + * properties, own and inherited, of `object` are bound. + * + * **Note:** This method does not set the "length" property of bound functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Object} object The object to bind and assign the bound methods to. + * @param {...(string|string[])} [methodNames] The object method names to bind, + * specified as individual method names or arrays of method names. + * @returns {Object} Returns `object`. + * @example + * + * var view = { + * 'label': 'docs', + * 'onClick': function() { + * console.log('clicked ' + this.label); + * } + * }; + * + * _.bindAll(view); + * jQuery('#docs').on('click', view.onClick); + * // => logs 'clicked docs' when the element is clicked + */ + var bindAll = restParam(function(object, methodNames) { + methodNames = methodNames.length ? baseFlatten(methodNames) : functions(object); + + var index = -1, + length = methodNames.length; + + while (++index < length) { + var key = methodNames[index]; + object[key] = createWrapper(object[key], BIND_FLAG, object); + } + return object; + }); + + /** + * Creates a function that invokes the method at `object[key]` and prepends + * any additional `_.bindKey` arguments to those provided to the bound function. + * + * This method differs from `_.bind` by allowing bound functions to reference + * methods that may be redefined or don't yet exist. + * See [Peter Michaux's article](http://peter.michaux.ca/articles/lazy-function-definition-pattern) + * for more details. + * + * The `_.bindKey.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for partially applied arguments. + * + * @static + * @memberOf _ + * @category Function + * @param {Object} object The object the method belongs to. + * @param {string} key The key of the method. + * @param {...*} [partials] The arguments to be partially applied. + * @returns {Function} Returns the new bound function. + * @example + * + * var object = { + * 'user': 'fred', + * 'greet': function(greeting, punctuation) { + * return greeting + ' ' + this.user + punctuation; + * } + * }; + * + * var bound = _.bindKey(object, 'greet', 'hi'); + * bound('!'); + * // => 'hi fred!' + * + * object.greet = function(greeting, punctuation) { + * return greeting + 'ya ' + this.user + punctuation; + * }; + * + * bound('!'); + * // => 'hiya fred!' + * + * // using placeholders + * var bound = _.bindKey(object, 'greet', _, '!'); + * bound('hi'); + * // => 'hiya fred!' + */ + var bindKey = restParam(function(object, key, partials) { + var bitmask = BIND_FLAG | BIND_KEY_FLAG; + if (partials.length) { + var holders = replaceHolders(partials, bindKey.placeholder); + bitmask |= PARTIAL_FLAG; + } + return createWrapper(key, bitmask, object, partials, holders); + }); + + /** + * Creates a function that accepts one or more arguments of `func` that when + * called either invokes `func` returning its result, if all `func` arguments + * have been provided, or returns a function that accepts one or more of the + * remaining `func` arguments, and so on. The arity of `func` may be specified + * if `func.length` is not sufficient. + * + * The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, + * may be used as a placeholder for provided arguments. + * + * **Note:** This method does not set the "length" property of curried functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to curry. + * @param {number} [arity=func.length] The arity of `func`. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Function} Returns the new curried function. + * @example + * + * var abc = function(a, b, c) { + * return [a, b, c]; + * }; + * + * var curried = _.curry(abc); + * + * curried(1)(2)(3); + * // => [1, 2, 3] + * + * curried(1, 2)(3); + * // => [1, 2, 3] + * + * curried(1, 2, 3); + * // => [1, 2, 3] + * + * // using placeholders + * curried(1)(_, 3)(2); + * // => [1, 2, 3] + */ + var curry = createCurry(CURRY_FLAG); + + /** + * This method is like `_.curry` except that arguments are applied to `func` + * in the manner of `_.partialRight` instead of `_.partial`. + * + * The `_.curryRight.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for provided arguments. + * + * **Note:** This method does not set the "length" property of curried functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to curry. + * @param {number} [arity=func.length] The arity of `func`. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Function} Returns the new curried function. + * @example + * + * var abc = function(a, b, c) { + * return [a, b, c]; + * }; + * + * var curried = _.curryRight(abc); + * + * curried(3)(2)(1); + * // => [1, 2, 3] + * + * curried(2, 3)(1); + * // => [1, 2, 3] + * + * curried(1, 2, 3); + * // => [1, 2, 3] + * + * // using placeholders + * curried(3)(1, _)(2); + * // => [1, 2, 3] + */ + var curryRight = createCurry(CURRY_RIGHT_FLAG); + + /** + * Creates a debounced function that delays invoking `func` until after `wait` + * milliseconds have elapsed since the last time the debounced function was + * invoked. The debounced function comes with a `cancel` method to cancel + * delayed invocations. Provide an options object to indicate that `func` + * should be invoked on the leading and/or trailing edge of the `wait` timeout. + * Subsequent calls to the debounced function return the result of the last + * `func` invocation. + * + * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked + * on the trailing edge of the timeout only if the the debounced function is + * invoked more than once during the `wait` timeout. + * + * See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation) + * for details over the differences between `_.debounce` and `_.throttle`. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to debounce. + * @param {number} [wait=0] The number of milliseconds to delay. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=false] Specify invoking on the leading + * edge of the timeout. + * @param {number} [options.maxWait] The maximum time `func` is allowed to be + * delayed before it is invoked. + * @param {boolean} [options.trailing=true] Specify invoking on the trailing + * edge of the timeout. + * @returns {Function} Returns the new debounced function. + * @example + * + * // avoid costly calculations while the window size is in flux + * jQuery(window).on('resize', _.debounce(calculateLayout, 150)); + * + * // invoke `sendMail` when the click event is fired, debouncing subsequent calls + * jQuery('#postbox').on('click', _.debounce(sendMail, 300, { + * 'leading': true, + * 'trailing': false + * })); + * + * // ensure `batchLog` is invoked once after 1 second of debounced calls + * var source = new EventSource('/stream'); + * jQuery(source).on('message', _.debounce(batchLog, 250, { + * 'maxWait': 1000 + * })); + * + * // cancel a debounced call + * var todoChanges = _.debounce(batchLog, 1000); + * Object.observe(models.todo, todoChanges); + * + * Object.observe(models, function(changes) { + * if (_.find(changes, { 'user': 'todo', 'type': 'delete'})) { + * todoChanges.cancel(); + * } + * }, ['delete']); + * + * // ...at some point `models.todo` is changed + * models.todo.completed = true; + * + * // ...before 1 second has passed `models.todo` is deleted + * // which cancels the debounced `todoChanges` call + * delete models.todo; + */ + function debounce(func, wait, options) { + var args, + maxTimeoutId, + result, + stamp, + thisArg, + timeoutId, + trailingCall, + lastCalled = 0, + maxWait = false, + trailing = true; + + if (typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + wait = wait < 0 ? 0 : (+wait || 0); + if (options === true) { + var leading = true; + trailing = false; + } else if (isObject(options)) { + leading = !!options.leading; + maxWait = 'maxWait' in options && nativeMax(+options.maxWait || 0, wait); + trailing = 'trailing' in options ? !!options.trailing : trailing; + } + + function cancel() { + if (timeoutId) { + clearTimeout(timeoutId); + } + if (maxTimeoutId) { + clearTimeout(maxTimeoutId); + } + lastCalled = 0; + maxTimeoutId = timeoutId = trailingCall = undefined; + } + + function complete(isCalled, id) { + if (id) { + clearTimeout(id); + } + maxTimeoutId = timeoutId = trailingCall = undefined; + if (isCalled) { + lastCalled = now(); + result = func.apply(thisArg, args); + if (!timeoutId && !maxTimeoutId) { + args = thisArg = undefined; + } + } + } + + function delayed() { + var remaining = wait - (now() - stamp); + if (remaining <= 0 || remaining > wait) { + complete(trailingCall, maxTimeoutId); + } else { + timeoutId = setTimeout(delayed, remaining); + } + } + + function maxDelayed() { + complete(trailing, timeoutId); + } + + function debounced() { + args = arguments; + stamp = now(); + thisArg = this; + trailingCall = trailing && (timeoutId || !leading); + + if (maxWait === false) { + var leadingCall = leading && !timeoutId; + } else { + if (!maxTimeoutId && !leading) { + lastCalled = stamp; + } + var remaining = maxWait - (stamp - lastCalled), + isCalled = remaining <= 0 || remaining > maxWait; + + if (isCalled) { + if (maxTimeoutId) { + maxTimeoutId = clearTimeout(maxTimeoutId); + } + lastCalled = stamp; + result = func.apply(thisArg, args); + } + else if (!maxTimeoutId) { + maxTimeoutId = setTimeout(maxDelayed, remaining); + } + } + if (isCalled && timeoutId) { + timeoutId = clearTimeout(timeoutId); + } + else if (!timeoutId && wait !== maxWait) { + timeoutId = setTimeout(delayed, wait); + } + if (leadingCall) { + isCalled = true; + result = func.apply(thisArg, args); + } + if (isCalled && !timeoutId && !maxTimeoutId) { + args = thisArg = undefined; + } + return result; + } + debounced.cancel = cancel; + return debounced; + } + + /** + * Defers invoking the `func` until the current call stack has cleared. Any + * additional arguments are provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to defer. + * @param {...*} [args] The arguments to invoke the function with. + * @returns {number} Returns the timer id. + * @example + * + * _.defer(function(text) { + * console.log(text); + * }, 'deferred'); + * // logs 'deferred' after one or more milliseconds + */ + var defer = restParam(function(func, args) { + return baseDelay(func, 1, args); + }); + + /** + * Invokes `func` after `wait` milliseconds. Any additional arguments are + * provided to `func` when it is invoked. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to delay. + * @param {number} wait The number of milliseconds to delay invocation. + * @param {...*} [args] The arguments to invoke the function with. + * @returns {number} Returns the timer id. + * @example + * + * _.delay(function(text) { + * console.log(text); + * }, 1000, 'later'); + * // => logs 'later' after one second + */ + var delay = restParam(function(func, wait, args) { + return baseDelay(func, wait, args); + }); + + /** + * Creates a function that returns the result of invoking the provided + * functions with the `this` binding of the created function, where each + * successive invocation is supplied the return value of the previous. + * + * @static + * @memberOf _ + * @category Function + * @param {...Function} [funcs] Functions to invoke. + * @returns {Function} Returns the new function. + * @example + * + * function square(n) { + * return n * n; + * } + * + * var addSquare = _.flow(_.add, square); + * addSquare(1, 2); + * // => 9 + */ + var flow = createFlow(); + + /** + * This method is like `_.flow` except that it creates a function that + * invokes the provided functions from right to left. + * + * @static + * @memberOf _ + * @alias backflow, compose + * @category Function + * @param {...Function} [funcs] Functions to invoke. + * @returns {Function} Returns the new function. + * @example + * + * function square(n) { + * return n * n; + * } + * + * var addSquare = _.flowRight(square, _.add); + * addSquare(1, 2); + * // => 9 + */ + var flowRight = createFlow(true); + + /** + * Creates a function that memoizes the result of `func`. If `resolver` is + * provided it determines the cache key for storing the result based on the + * arguments provided to the memoized function. By default, the first argument + * provided to the memoized function is coerced to a string and used as the + * cache key. The `func` is invoked with the `this` binding of the memoized + * function. + * + * **Note:** The cache is exposed as the `cache` property on the memoized + * function. Its creation may be customized by replacing the `_.memoize.Cache` + * constructor with one whose instances implement the [`Map`](http://ecma-international.org/ecma-262/6.0/#sec-properties-of-the-map-prototype-object) + * method interface of `get`, `has`, and `set`. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to have its output memoized. + * @param {Function} [resolver] The function to resolve the cache key. + * @returns {Function} Returns the new memoizing function. + * @example + * + * var upperCase = _.memoize(function(string) { + * return string.toUpperCase(); + * }); + * + * upperCase('fred'); + * // => 'FRED' + * + * // modifying the result cache + * upperCase.cache.set('fred', 'BARNEY'); + * upperCase('fred'); + * // => 'BARNEY' + * + * // replacing `_.memoize.Cache` + * var object = { 'user': 'fred' }; + * var other = { 'user': 'barney' }; + * var identity = _.memoize(_.identity); + * + * identity(object); + * // => { 'user': 'fred' } + * identity(other); + * // => { 'user': 'fred' } + * + * _.memoize.Cache = WeakMap; + * var identity = _.memoize(_.identity); + * + * identity(object); + * // => { 'user': 'fred' } + * identity(other); + * // => { 'user': 'barney' } + */ + function memoize(func, resolver) { + if (typeof func != 'function' || (resolver && typeof resolver != 'function')) { + throw new TypeError(FUNC_ERROR_TEXT); + } + var memoized = function() { + var args = arguments, + key = resolver ? resolver.apply(this, args) : args[0], + cache = memoized.cache; + + if (cache.has(key)) { + return cache.get(key); + } + var result = func.apply(this, args); + memoized.cache = cache.set(key, result); + return result; + }; + memoized.cache = new memoize.Cache; + return memoized; + } + + /** + * Creates a function that runs each argument through a corresponding + * transform function. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to wrap. + * @param {...(Function|Function[])} [transforms] The functions to transform + * arguments, specified as individual functions or arrays of functions. + * @returns {Function} Returns the new function. + * @example + * + * function doubled(n) { + * return n * 2; + * } + * + * function square(n) { + * return n * n; + * } + * + * var modded = _.modArgs(function(x, y) { + * return [x, y]; + * }, square, doubled); + * + * modded(1, 2); + * // => [1, 4] + * + * modded(5, 10); + * // => [25, 20] + */ + var modArgs = restParam(function(func, transforms) { + transforms = baseFlatten(transforms); + if (typeof func != 'function' || !arrayEvery(transforms, baseIsFunction)) { + throw new TypeError(FUNC_ERROR_TEXT); + } + var length = transforms.length; + return restParam(function(args) { + var index = nativeMin(args.length, length); + while (index--) { + args[index] = transforms[index](args[index]); + } + return func.apply(this, args); + }); + }); + + /** + * Creates a function that negates the result of the predicate `func`. The + * `func` predicate is invoked with the `this` binding and arguments of the + * created function. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} predicate The predicate to negate. + * @returns {Function} Returns the new function. + * @example + * + * function isEven(n) { + * return n % 2 == 0; + * } + * + * _.filter([1, 2, 3, 4, 5, 6], _.negate(isEven)); + * // => [1, 3, 5] + */ + function negate(predicate) { + if (typeof predicate != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + return function() { + return !predicate.apply(this, arguments); + }; + } + + /** + * Creates a function that is restricted to invoking `func` once. Repeat calls + * to the function return the value of the first call. The `func` is invoked + * with the `this` binding and arguments of the created function. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to restrict. + * @returns {Function} Returns the new restricted function. + * @example + * + * var initialize = _.once(createApplication); + * initialize(); + * initialize(); + * // `initialize` invokes `createApplication` once + */ + function once(func) { + return before(2, func); + } + + /** + * Creates a function that invokes `func` with `partial` arguments prepended + * to those provided to the new function. This method is like `_.bind` except + * it does **not** alter the `this` binding. + * + * The `_.partial.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for partially applied arguments. + * + * **Note:** This method does not set the "length" property of partially + * applied functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to partially apply arguments to. + * @param {...*} [partials] The arguments to be partially applied. + * @returns {Function} Returns the new partially applied function. + * @example + * + * var greet = function(greeting, name) { + * return greeting + ' ' + name; + * }; + * + * var sayHelloTo = _.partial(greet, 'hello'); + * sayHelloTo('fred'); + * // => 'hello fred' + * + * // using placeholders + * var greetFred = _.partial(greet, _, 'fred'); + * greetFred('hi'); + * // => 'hi fred' + */ + var partial = createPartial(PARTIAL_FLAG); + + /** + * This method is like `_.partial` except that partially applied arguments + * are appended to those provided to the new function. + * + * The `_.partialRight.placeholder` value, which defaults to `_` in monolithic + * builds, may be used as a placeholder for partially applied arguments. + * + * **Note:** This method does not set the "length" property of partially + * applied functions. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to partially apply arguments to. + * @param {...*} [partials] The arguments to be partially applied. + * @returns {Function} Returns the new partially applied function. + * @example + * + * var greet = function(greeting, name) { + * return greeting + ' ' + name; + * }; + * + * var greetFred = _.partialRight(greet, 'fred'); + * greetFred('hi'); + * // => 'hi fred' + * + * // using placeholders + * var sayHelloTo = _.partialRight(greet, 'hello', _); + * sayHelloTo('fred'); + * // => 'hello fred' + */ + var partialRight = createPartial(PARTIAL_RIGHT_FLAG); + + /** + * Creates a function that invokes `func` with arguments arranged according + * to the specified indexes where the argument value at the first index is + * provided as the first argument, the argument value at the second index is + * provided as the second argument, and so on. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to rearrange arguments for. + * @param {...(number|number[])} indexes The arranged argument indexes, + * specified as individual indexes or arrays of indexes. + * @returns {Function} Returns the new function. + * @example + * + * var rearged = _.rearg(function(a, b, c) { + * return [a, b, c]; + * }, 2, 0, 1); + * + * rearged('b', 'c', 'a') + * // => ['a', 'b', 'c'] + * + * var map = _.rearg(_.map, [1, 0]); + * map(function(n) { + * return n * 3; + * }, [1, 2, 3]); + * // => [3, 6, 9] + */ + var rearg = restParam(function(func, indexes) { + return createWrapper(func, REARG_FLAG, undefined, undefined, undefined, baseFlatten(indexes)); + }); + + /** + * Creates a function that invokes `func` with the `this` binding of the + * created function and arguments from `start` and beyond provided as an array. + * + * **Note:** This method is based on the [rest parameter](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Functions/rest_parameters). + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to apply a rest parameter to. + * @param {number} [start=func.length-1] The start position of the rest parameter. + * @returns {Function} Returns the new function. + * @example + * + * var say = _.restParam(function(what, names) { + * return what + ' ' + _.initial(names).join(', ') + + * (_.size(names) > 1 ? ', & ' : '') + _.last(names); + * }); + * + * say('hello', 'fred', 'barney', 'pebbles'); + * // => 'hello fred, barney, & pebbles' + */ + function restParam(func, start) { + if (typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + start = nativeMax(start === undefined ? (func.length - 1) : (+start || 0), 0); + return function() { + var args = arguments, + index = -1, + length = nativeMax(args.length - start, 0), + rest = Array(length); + + while (++index < length) { + rest[index] = args[start + index]; + } + switch (start) { + case 0: return func.call(this, rest); + case 1: return func.call(this, args[0], rest); + case 2: return func.call(this, args[0], args[1], rest); + } + var otherArgs = Array(start + 1); + index = -1; + while (++index < start) { + otherArgs[index] = args[index]; + } + otherArgs[start] = rest; + return func.apply(this, otherArgs); + }; + } + + /** + * Creates a function that invokes `func` with the `this` binding of the created + * function and an array of arguments much like [`Function#apply`](https://es5.github.io/#x15.3.4.3). + * + * **Note:** This method is based on the [spread operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Spread_operator). + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to spread arguments over. + * @returns {Function} Returns the new function. + * @example + * + * var say = _.spread(function(who, what) { + * return who + ' says ' + what; + * }); + * + * say(['fred', 'hello']); + * // => 'fred says hello' + * + * // with a Promise + * var numbers = Promise.all([ + * Promise.resolve(40), + * Promise.resolve(36) + * ]); + * + * numbers.then(_.spread(function(x, y) { + * return x + y; + * })); + * // => a Promise of 76 + */ + function spread(func) { + if (typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + return function(array) { + return func.apply(this, array); + }; + } + + /** + * Creates a throttled function that only invokes `func` at most once per + * every `wait` milliseconds. The throttled function comes with a `cancel` + * method to cancel delayed invocations. Provide an options object to indicate + * that `func` should be invoked on the leading and/or trailing edge of the + * `wait` timeout. Subsequent calls to the throttled function return the + * result of the last `func` call. + * + * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked + * on the trailing edge of the timeout only if the the throttled function is + * invoked more than once during the `wait` timeout. + * + * See [David Corbacho's article](http://drupalmotion.com/article/debounce-and-throttle-visual-explanation) + * for details over the differences between `_.throttle` and `_.debounce`. + * + * @static + * @memberOf _ + * @category Function + * @param {Function} func The function to throttle. + * @param {number} [wait=0] The number of milliseconds to throttle invocations to. + * @param {Object} [options] The options object. + * @param {boolean} [options.leading=true] Specify invoking on the leading + * edge of the timeout. + * @param {boolean} [options.trailing=true] Specify invoking on the trailing + * edge of the timeout. + * @returns {Function} Returns the new throttled function. + * @example + * + * // avoid excessively updating the position while scrolling + * jQuery(window).on('scroll', _.throttle(updatePosition, 100)); + * + * // invoke `renewToken` when the click event is fired, but not more than once every 5 minutes + * jQuery('.interactive').on('click', _.throttle(renewToken, 300000, { + * 'trailing': false + * })); + * + * // cancel a trailing throttled call + * jQuery(window).on('popstate', throttled.cancel); + */ + function throttle(func, wait, options) { + var leading = true, + trailing = true; + + if (typeof func != 'function') { + throw new TypeError(FUNC_ERROR_TEXT); + } + if (options === false) { + leading = false; + } else if (isObject(options)) { + leading = 'leading' in options ? !!options.leading : leading; + trailing = 'trailing' in options ? !!options.trailing : trailing; + } + return debounce(func, wait, { 'leading': leading, 'maxWait': +wait, 'trailing': trailing }); + } + + /** + * Creates a function that provides `value` to the wrapper function as its + * first argument. Any additional arguments provided to the function are + * appended to those provided to the wrapper function. The wrapper is invoked + * with the `this` binding of the created function. + * + * @static + * @memberOf _ + * @category Function + * @param {*} value The value to wrap. + * @param {Function} wrapper The wrapper function. + * @returns {Function} Returns the new function. + * @example + * + * var p = _.wrap(_.escape, function(func, text) { + * return '

' + func(text) + '

'; + * }); + * + * p('fred, barney, & pebbles'); + * // => '

fred, barney, & pebbles

' + */ + function wrap(value, wrapper) { + wrapper = wrapper == null ? identity : wrapper; + return createWrapper(wrapper, PARTIAL_FLAG, undefined, [value], []); + } + + /*------------------------------------------------------------------------*/ + + /** + * Creates a clone of `value`. If `isDeep` is `true` nested objects are cloned, + * otherwise they are assigned by reference. If `customizer` is provided it is + * invoked to produce the cloned values. If `customizer` returns `undefined` + * cloning is handled by the method instead. The `customizer` is bound to + * `thisArg` and invoked with two argument; (value [, index|key, object]). + * + * **Note:** This method is loosely based on the + * [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm). + * The enumerable properties of `arguments` objects and objects created by + * constructors other than `Object` are cloned to plain `Object` objects. An + * empty object is returned for uncloneable values such as functions, DOM nodes, + * Maps, Sets, and WeakMaps. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to clone. + * @param {boolean} [isDeep] Specify a deep clone. + * @param {Function} [customizer] The function to customize cloning values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {*} Returns the cloned value. + * @example + * + * var users = [ + * { 'user': 'barney' }, + * { 'user': 'fred' } + * ]; + * + * var shallow = _.clone(users); + * shallow[0] === users[0]; + * // => true + * + * var deep = _.clone(users, true); + * deep[0] === users[0]; + * // => false + * + * // using a customizer callback + * var el = _.clone(document.body, function(value) { + * if (_.isElement(value)) { + * return value.cloneNode(false); + * } + * }); + * + * el === document.body + * // => false + * el.nodeName + * // => BODY + * el.childNodes.length; + * // => 0 + */ + function clone(value, isDeep, customizer, thisArg) { + if (isDeep && typeof isDeep != 'boolean' && isIterateeCall(value, isDeep, customizer)) { + isDeep = false; + } + else if (typeof isDeep == 'function') { + thisArg = customizer; + customizer = isDeep; + isDeep = false; + } + return typeof customizer == 'function' + ? baseClone(value, isDeep, bindCallback(customizer, thisArg, 1)) + : baseClone(value, isDeep); + } + + /** + * Creates a deep clone of `value`. If `customizer` is provided it is invoked + * to produce the cloned values. If `customizer` returns `undefined` cloning + * is handled by the method instead. The `customizer` is bound to `thisArg` + * and invoked with two argument; (value [, index|key, object]). + * + * **Note:** This method is loosely based on the + * [structured clone algorithm](http://www.w3.org/TR/html5/infrastructure.html#internal-structured-cloning-algorithm). + * The enumerable properties of `arguments` objects and objects created by + * constructors other than `Object` are cloned to plain `Object` objects. An + * empty object is returned for uncloneable values such as functions, DOM nodes, + * Maps, Sets, and WeakMaps. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to deep clone. + * @param {Function} [customizer] The function to customize cloning values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {*} Returns the deep cloned value. + * @example + * + * var users = [ + * { 'user': 'barney' }, + * { 'user': 'fred' } + * ]; + * + * var deep = _.cloneDeep(users); + * deep[0] === users[0]; + * // => false + * + * // using a customizer callback + * var el = _.cloneDeep(document.body, function(value) { + * if (_.isElement(value)) { + * return value.cloneNode(true); + * } + * }); + * + * el === document.body + * // => false + * el.nodeName + * // => BODY + * el.childNodes.length; + * // => 20 + */ + function cloneDeep(value, customizer, thisArg) { + return typeof customizer == 'function' + ? baseClone(value, true, bindCallback(customizer, thisArg, 1)) + : baseClone(value, true); + } + + /** + * Checks if `value` is greater than `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is greater than `other`, else `false`. + * @example + * + * _.gt(3, 1); + * // => true + * + * _.gt(3, 3); + * // => false + * + * _.gt(1, 3); + * // => false + */ + function gt(value, other) { + return value > other; + } + + /** + * Checks if `value` is greater than or equal to `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is greater than or equal to `other`, else `false`. + * @example + * + * _.gte(3, 1); + * // => true + * + * _.gte(3, 3); + * // => true + * + * _.gte(1, 3); + * // => false + */ + function gte(value, other) { + return value >= other; + } + + /** + * Checks if `value` is classified as an `arguments` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isArguments(function() { return arguments; }()); + * // => true + * + * _.isArguments([1, 2, 3]); + * // => false + */ + function isArguments(value) { + return isObjectLike(value) && isArrayLike(value) && + hasOwnProperty.call(value, 'callee') && !propertyIsEnumerable.call(value, 'callee'); + } + + /** + * Checks if `value` is classified as an `Array` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isArray([1, 2, 3]); + * // => true + * + * _.isArray(function() { return arguments; }()); + * // => false + */ + var isArray = nativeIsArray || function(value) { + return isObjectLike(value) && isLength(value.length) && objToString.call(value) == arrayTag; + }; + + /** + * Checks if `value` is classified as a boolean primitive or object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isBoolean(false); + * // => true + * + * _.isBoolean(null); + * // => false + */ + function isBoolean(value) { + return value === true || value === false || (isObjectLike(value) && objToString.call(value) == boolTag); + } + + /** + * Checks if `value` is classified as a `Date` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isDate(new Date); + * // => true + * + * _.isDate('Mon April 23 2012'); + * // => false + */ + function isDate(value) { + return isObjectLike(value) && objToString.call(value) == dateTag; + } + + /** + * Checks if `value` is a DOM element. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a DOM element, else `false`. + * @example + * + * _.isElement(document.body); + * // => true + * + * _.isElement(''); + * // => false + */ + function isElement(value) { + return !!value && value.nodeType === 1 && isObjectLike(value) && !isPlainObject(value); + } + + /** + * Checks if `value` is empty. A value is considered empty unless it is an + * `arguments` object, array, string, or jQuery-like collection with a length + * greater than `0` or an object with own enumerable properties. + * + * @static + * @memberOf _ + * @category Lang + * @param {Array|Object|string} value The value to inspect. + * @returns {boolean} Returns `true` if `value` is empty, else `false`. + * @example + * + * _.isEmpty(null); + * // => true + * + * _.isEmpty(true); + * // => true + * + * _.isEmpty(1); + * // => true + * + * _.isEmpty([1, 2, 3]); + * // => false + * + * _.isEmpty({ 'a': 1 }); + * // => false + */ + function isEmpty(value) { + if (value == null) { + return true; + } + if (isArrayLike(value) && (isArray(value) || isString(value) || isArguments(value) || + (isObjectLike(value) && isFunction(value.splice)))) { + return !value.length; + } + return !keys(value).length; + } + + /** + * Performs a deep comparison between two values to determine if they are + * equivalent. If `customizer` is provided it is invoked to compare values. + * If `customizer` returns `undefined` comparisons are handled by the method + * instead. The `customizer` is bound to `thisArg` and invoked with three + * arguments: (value, other [, index|key]). + * + * **Note:** This method supports comparing arrays, booleans, `Date` objects, + * numbers, `Object` objects, regexes, and strings. Objects are compared by + * their own, not inherited, enumerable properties. Functions and DOM nodes + * are **not** supported. Provide a customizer function to extend support + * for comparing other values. + * + * @static + * @memberOf _ + * @alias eq + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @param {Function} [customizer] The function to customize value comparisons. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {boolean} Returns `true` if the values are equivalent, else `false`. + * @example + * + * var object = { 'user': 'fred' }; + * var other = { 'user': 'fred' }; + * + * object == other; + * // => false + * + * _.isEqual(object, other); + * // => true + * + * // using a customizer callback + * var array = ['hello', 'goodbye']; + * var other = ['hi', 'goodbye']; + * + * _.isEqual(array, other, function(value, other) { + * if (_.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/)) { + * return true; + * } + * }); + * // => true + */ + function isEqual(value, other, customizer, thisArg) { + customizer = typeof customizer == 'function' ? bindCallback(customizer, thisArg, 3) : undefined; + var result = customizer ? customizer(value, other) : undefined; + return result === undefined ? baseIsEqual(value, other, customizer) : !!result; + } + + /** + * Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, + * `SyntaxError`, `TypeError`, or `URIError` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an error object, else `false`. + * @example + * + * _.isError(new Error); + * // => true + * + * _.isError(Error); + * // => false + */ + function isError(value) { + return isObjectLike(value) && typeof value.message == 'string' && objToString.call(value) == errorTag; + } + + /** + * Checks if `value` is a finite primitive number. + * + * **Note:** This method is based on [`Number.isFinite`](http://ecma-international.org/ecma-262/6.0/#sec-number.isfinite). + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a finite number, else `false`. + * @example + * + * _.isFinite(10); + * // => true + * + * _.isFinite('10'); + * // => false + * + * _.isFinite(true); + * // => false + * + * _.isFinite(Object(10)); + * // => false + * + * _.isFinite(Infinity); + * // => false + */ + function isFinite(value) { + return typeof value == 'number' && nativeIsFinite(value); + } + + /** + * Checks if `value` is classified as a `Function` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isFunction(_); + * // => true + * + * _.isFunction(/abc/); + * // => false + */ + function isFunction(value) { + // The use of `Object#toString` avoids issues with the `typeof` operator + // in older versions of Chrome and Safari which return 'function' for regexes + // and Safari 8 equivalents which return 'object' for typed array constructors. + return isObject(value) && objToString.call(value) == funcTag; + } + + /** + * Checks if `value` is the [language type](https://es5.github.io/#x8) of `Object`. + * (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`) + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is an object, else `false`. + * @example + * + * _.isObject({}); + * // => true + * + * _.isObject([1, 2, 3]); + * // => true + * + * _.isObject(1); + * // => false + */ + function isObject(value) { + // Avoid a V8 JIT bug in Chrome 19-20. + // See https://code.google.com/p/v8/issues/detail?id=2291 for more details. + var type = typeof value; + return !!value && (type == 'object' || type == 'function'); + } + + /** + * Performs a deep comparison between `object` and `source` to determine if + * `object` contains equivalent property values. If `customizer` is provided + * it is invoked to compare values. If `customizer` returns `undefined` + * comparisons are handled by the method instead. The `customizer` is bound + * to `thisArg` and invoked with three arguments: (value, other, index|key). + * + * **Note:** This method supports comparing properties of arrays, booleans, + * `Date` objects, numbers, `Object` objects, regexes, and strings. Functions + * and DOM nodes are **not** supported. Provide a customizer function to extend + * support for comparing other values. + * + * @static + * @memberOf _ + * @category Lang + * @param {Object} object The object to inspect. + * @param {Object} source The object of property values to match. + * @param {Function} [customizer] The function to customize value comparisons. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {boolean} Returns `true` if `object` is a match, else `false`. + * @example + * + * var object = { 'user': 'fred', 'age': 40 }; + * + * _.isMatch(object, { 'age': 40 }); + * // => true + * + * _.isMatch(object, { 'age': 36 }); + * // => false + * + * // using a customizer callback + * var object = { 'greeting': 'hello' }; + * var source = { 'greeting': 'hi' }; + * + * _.isMatch(object, source, function(value, other) { + * return _.every([value, other], RegExp.prototype.test, /^h(?:i|ello)$/) || undefined; + * }); + * // => true + */ + function isMatch(object, source, customizer, thisArg) { + customizer = typeof customizer == 'function' ? bindCallback(customizer, thisArg, 3) : undefined; + return baseIsMatch(object, getMatchData(source), customizer); + } + + /** + * Checks if `value` is `NaN`. + * + * **Note:** This method is not the same as [`isNaN`](https://es5.github.io/#x15.1.2.4) + * which returns `true` for `undefined` and other non-numeric values. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `NaN`, else `false`. + * @example + * + * _.isNaN(NaN); + * // => true + * + * _.isNaN(new Number(NaN)); + * // => true + * + * isNaN(undefined); + * // => true + * + * _.isNaN(undefined); + * // => false + */ + function isNaN(value) { + // An `NaN` primitive is the only value that is not equal to itself. + // Perform the `toStringTag` check first to avoid errors with some host objects in IE. + return isNumber(value) && value != +value; + } + + /** + * Checks if `value` is a native function. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a native function, else `false`. + * @example + * + * _.isNative(Array.prototype.push); + * // => true + * + * _.isNative(_); + * // => false + */ + function isNative(value) { + if (value == null) { + return false; + } + if (isFunction(value)) { + return reIsNative.test(fnToString.call(value)); + } + return isObjectLike(value) && reIsHostCtor.test(value); + } + + /** + * Checks if `value` is `null`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `null`, else `false`. + * @example + * + * _.isNull(null); + * // => true + * + * _.isNull(void 0); + * // => false + */ + function isNull(value) { + return value === null; + } + + /** + * Checks if `value` is classified as a `Number` primitive or object. + * + * **Note:** To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified + * as numbers, use the `_.isFinite` method. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isNumber(8.4); + * // => true + * + * _.isNumber(NaN); + * // => true + * + * _.isNumber('8.4'); + * // => false + */ + function isNumber(value) { + return typeof value == 'number' || (isObjectLike(value) && objToString.call(value) == numberTag); + } + + /** + * Checks if `value` is a plain object, that is, an object created by the + * `Object` constructor or one with a `[[Prototype]]` of `null`. + * + * **Note:** This method assumes objects created by the `Object` constructor + * have no inherited enumerable properties. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is a plain object, else `false`. + * @example + * + * function Foo() { + * this.a = 1; + * } + * + * _.isPlainObject(new Foo); + * // => false + * + * _.isPlainObject([1, 2, 3]); + * // => false + * + * _.isPlainObject({ 'x': 0, 'y': 0 }); + * // => true + * + * _.isPlainObject(Object.create(null)); + * // => true + */ + function isPlainObject(value) { + var Ctor; + + // Exit early for non `Object` objects. + if (!(isObjectLike(value) && objToString.call(value) == objectTag && !isArguments(value)) || + (!hasOwnProperty.call(value, 'constructor') && (Ctor = value.constructor, typeof Ctor == 'function' && !(Ctor instanceof Ctor)))) { + return false; + } + // IE < 9 iterates inherited properties before own properties. If the first + // iterated property is an object's own property then there are no inherited + // enumerable properties. + var result; + // In most environments an object's own properties are iterated before + // its inherited properties. If the last iterated property is an object's + // own property then there are no inherited enumerable properties. + baseForIn(value, function(subValue, key) { + result = key; + }); + return result === undefined || hasOwnProperty.call(value, result); + } + + /** + * Checks if `value` is classified as a `RegExp` object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isRegExp(/abc/); + * // => true + * + * _.isRegExp('/abc/'); + * // => false + */ + function isRegExp(value) { + return isObject(value) && objToString.call(value) == regexpTag; + } + + /** + * Checks if `value` is classified as a `String` primitive or object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isString('abc'); + * // => true + * + * _.isString(1); + * // => false + */ + function isString(value) { + return typeof value == 'string' || (isObjectLike(value) && objToString.call(value) == stringTag); + } + + /** + * Checks if `value` is classified as a typed array. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is correctly classified, else `false`. + * @example + * + * _.isTypedArray(new Uint8Array); + * // => true + * + * _.isTypedArray([]); + * // => false + */ + function isTypedArray(value) { + return isObjectLike(value) && isLength(value.length) && !!typedArrayTags[objToString.call(value)]; + } + + /** + * Checks if `value` is `undefined`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to check. + * @returns {boolean} Returns `true` if `value` is `undefined`, else `false`. + * @example + * + * _.isUndefined(void 0); + * // => true + * + * _.isUndefined(null); + * // => false + */ + function isUndefined(value) { + return value === undefined; + } + + /** + * Checks if `value` is less than `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is less than `other`, else `false`. + * @example + * + * _.lt(1, 3); + * // => true + * + * _.lt(3, 3); + * // => false + * + * _.lt(3, 1); + * // => false + */ + function lt(value, other) { + return value < other; + } + + /** + * Checks if `value` is less than or equal to `other`. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to compare. + * @param {*} other The other value to compare. + * @returns {boolean} Returns `true` if `value` is less than or equal to `other`, else `false`. + * @example + * + * _.lte(1, 3); + * // => true + * + * _.lte(3, 3); + * // => true + * + * _.lte(3, 1); + * // => false + */ + function lte(value, other) { + return value <= other; + } + + /** + * Converts `value` to an array. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {Array} Returns the converted array. + * @example + * + * (function() { + * return _.toArray(arguments).slice(1); + * }(1, 2, 3)); + * // => [2, 3] + */ + function toArray(value) { + var length = value ? getLength(value) : 0; + if (!isLength(length)) { + return values(value); + } + if (!length) { + return []; + } + return arrayCopy(value); + } + + /** + * Converts `value` to a plain object flattening inherited enumerable + * properties of `value` to own properties of the plain object. + * + * @static + * @memberOf _ + * @category Lang + * @param {*} value The value to convert. + * @returns {Object} Returns the converted plain object. + * @example + * + * function Foo() { + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.assign({ 'a': 1 }, new Foo); + * // => { 'a': 1, 'b': 2 } + * + * _.assign({ 'a': 1 }, _.toPlainObject(new Foo)); + * // => { 'a': 1, 'b': 2, 'c': 3 } + */ + function toPlainObject(value) { + return baseCopy(value, keysIn(value)); + } + + /*------------------------------------------------------------------------*/ + + /** + * Recursively merges own enumerable properties of the source object(s), that + * don't resolve to `undefined` into the destination object. Subsequent sources + * overwrite property assignments of previous sources. If `customizer` is + * provided it is invoked to produce the merged values of the destination and + * source properties. If `customizer` returns `undefined` merging is handled + * by the method instead. The `customizer` is bound to `thisArg` and invoked + * with five arguments: (objectValue, sourceValue, key, object, source). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @param {Function} [customizer] The function to customize assigned values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {Object} Returns `object`. + * @example + * + * var users = { + * 'data': [{ 'user': 'barney' }, { 'user': 'fred' }] + * }; + * + * var ages = { + * 'data': [{ 'age': 36 }, { 'age': 40 }] + * }; + * + * _.merge(users, ages); + * // => { 'data': [{ 'user': 'barney', 'age': 36 }, { 'user': 'fred', 'age': 40 }] } + * + * // using a customizer callback + * var object = { + * 'fruits': ['apple'], + * 'vegetables': ['beet'] + * }; + * + * var other = { + * 'fruits': ['banana'], + * 'vegetables': ['carrot'] + * }; + * + * _.merge(object, other, function(a, b) { + * if (_.isArray(a)) { + * return a.concat(b); + * } + * }); + * // => { 'fruits': ['apple', 'banana'], 'vegetables': ['beet', 'carrot'] } + */ + var merge = createAssigner(baseMerge); + + /** + * Assigns own enumerable properties of source object(s) to the destination + * object. Subsequent sources overwrite property assignments of previous sources. + * If `customizer` is provided it is invoked to produce the assigned values. + * The `customizer` is bound to `thisArg` and invoked with five arguments: + * (objectValue, sourceValue, key, object, source). + * + * **Note:** This method mutates `object` and is based on + * [`Object.assign`](http://ecma-international.org/ecma-262/6.0/#sec-object.assign). + * + * @static + * @memberOf _ + * @alias extend + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @param {Function} [customizer] The function to customize assigned values. + * @param {*} [thisArg] The `this` binding of `customizer`. + * @returns {Object} Returns `object`. + * @example + * + * _.assign({ 'user': 'barney' }, { 'age': 40 }, { 'user': 'fred' }); + * // => { 'user': 'fred', 'age': 40 } + * + * // using a customizer callback + * var defaults = _.partialRight(_.assign, function(value, other) { + * return _.isUndefined(value) ? other : value; + * }); + * + * defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); + * // => { 'user': 'barney', 'age': 36 } + */ + var assign = createAssigner(function(object, source, customizer) { + return customizer + ? assignWith(object, source, customizer) + : baseAssign(object, source); + }); + + /** + * Creates an object that inherits from the given `prototype` object. If a + * `properties` object is provided its own enumerable properties are assigned + * to the created object. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} prototype The object to inherit from. + * @param {Object} [properties] The properties to assign to the object. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Object} Returns the new object. + * @example + * + * function Shape() { + * this.x = 0; + * this.y = 0; + * } + * + * function Circle() { + * Shape.call(this); + * } + * + * Circle.prototype = _.create(Shape.prototype, { + * 'constructor': Circle + * }); + * + * var circle = new Circle; + * circle instanceof Circle; + * // => true + * + * circle instanceof Shape; + * // => true + */ + function create(prototype, properties, guard) { + var result = baseCreate(prototype); + if (guard && isIterateeCall(prototype, properties, guard)) { + properties = undefined; + } + return properties ? baseAssign(result, properties) : result; + } + + /** + * Assigns own enumerable properties of source object(s) to the destination + * object for all destination properties that resolve to `undefined`. Once a + * property is set, additional values of the same property are ignored. + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * _.defaults({ 'user': 'barney' }, { 'age': 36 }, { 'user': 'fred' }); + * // => { 'user': 'barney', 'age': 36 } + */ + var defaults = createDefaults(assign, assignDefaults); + + /** + * This method is like `_.defaults` except that it recursively assigns + * default properties. + * + * **Note:** This method mutates `object`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The destination object. + * @param {...Object} [sources] The source objects. + * @returns {Object} Returns `object`. + * @example + * + * _.defaultsDeep({ 'user': { 'name': 'barney' } }, { 'user': { 'name': 'fred', 'age': 36 } }); + * // => { 'user': { 'name': 'barney', 'age': 36 } } + * + */ + var defaultsDeep = createDefaults(merge, mergeDefaults); + + /** + * This method is like `_.find` except that it returns the key of the first + * element `predicate` returns truthy for instead of the element itself. + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {string|undefined} Returns the key of the matched element, else `undefined`. + * @example + * + * var users = { + * 'barney': { 'age': 36, 'active': true }, + * 'fred': { 'age': 40, 'active': false }, + * 'pebbles': { 'age': 1, 'active': true } + * }; + * + * _.findKey(users, function(chr) { + * return chr.age < 40; + * }); + * // => 'barney' (iteration order is not guaranteed) + * + * // using the `_.matches` callback shorthand + * _.findKey(users, { 'age': 1, 'active': true }); + * // => 'pebbles' + * + * // using the `_.matchesProperty` callback shorthand + * _.findKey(users, 'active', false); + * // => 'fred' + * + * // using the `_.property` callback shorthand + * _.findKey(users, 'active'); + * // => 'barney' + */ + var findKey = createFindKey(baseForOwn); + + /** + * This method is like `_.findKey` except that it iterates over elements of + * a collection in the opposite order. + * + * If a property name is provided for `predicate` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `predicate` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to search. + * @param {Function|Object|string} [predicate=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {string|undefined} Returns the key of the matched element, else `undefined`. + * @example + * + * var users = { + * 'barney': { 'age': 36, 'active': true }, + * 'fred': { 'age': 40, 'active': false }, + * 'pebbles': { 'age': 1, 'active': true } + * }; + * + * _.findLastKey(users, function(chr) { + * return chr.age < 40; + * }); + * // => returns `pebbles` assuming `_.findKey` returns `barney` + * + * // using the `_.matches` callback shorthand + * _.findLastKey(users, { 'age': 36, 'active': true }); + * // => 'barney' + * + * // using the `_.matchesProperty` callback shorthand + * _.findLastKey(users, 'active', false); + * // => 'fred' + * + * // using the `_.property` callback shorthand + * _.findLastKey(users, 'active'); + * // => 'pebbles' + */ + var findLastKey = createFindKey(baseForOwnRight); + + /** + * Iterates over own and inherited enumerable properties of an object invoking + * `iteratee` for each property. The `iteratee` is bound to `thisArg` and invoked + * with three arguments: (value, key, object). Iteratee functions may exit + * iteration early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forIn(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'a', 'b', and 'c' (iteration order is not guaranteed) + */ + var forIn = createForIn(baseFor); + + /** + * This method is like `_.forIn` except that it iterates over properties of + * `object` in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forInRight(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'c', 'b', and 'a' assuming `_.forIn ` logs 'a', 'b', and 'c' + */ + var forInRight = createForIn(baseForRight); + + /** + * Iterates over own enumerable properties of an object invoking `iteratee` + * for each property. The `iteratee` is bound to `thisArg` and invoked with + * three arguments: (value, key, object). Iteratee functions may exit iteration + * early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forOwn(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'a' and 'b' (iteration order is not guaranteed) + */ + var forOwn = createForOwn(baseForOwn); + + /** + * This method is like `_.forOwn` except that it iterates over properties of + * `object` in the opposite order. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns `object`. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.forOwnRight(new Foo, function(value, key) { + * console.log(key); + * }); + * // => logs 'b' and 'a' assuming `_.forOwn` logs 'a' and 'b' + */ + var forOwnRight = createForOwn(baseForOwnRight); + + /** + * Creates an array of function property names from all enumerable properties, + * own and inherited, of `object`. + * + * @static + * @memberOf _ + * @alias methods + * @category Object + * @param {Object} object The object to inspect. + * @returns {Array} Returns the new array of property names. + * @example + * + * _.functions(_); + * // => ['after', 'ary', 'assign', ...] + */ + function functions(object) { + return baseFunctions(object, keysIn(object)); + } + + /** + * Gets the property value at `path` of `object`. If the resolved value is + * `undefined` the `defaultValue` is used in its place. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path of the property to get. + * @param {*} [defaultValue] The value returned if the resolved value is `undefined`. + * @returns {*} Returns the resolved value. + * @example + * + * var object = { 'a': [{ 'b': { 'c': 3 } }] }; + * + * _.get(object, 'a[0].b.c'); + * // => 3 + * + * _.get(object, ['a', '0', 'b', 'c']); + * // => 3 + * + * _.get(object, 'a.b.c', 'default'); + * // => 'default' + */ + function get(object, path, defaultValue) { + var result = object == null ? undefined : baseGet(object, toPath(path), path + ''); + return result === undefined ? defaultValue : result; + } + + /** + * Checks if `path` is a direct property. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path to check. + * @returns {boolean} Returns `true` if `path` is a direct property, else `false`. + * @example + * + * var object = { 'a': { 'b': { 'c': 3 } } }; + * + * _.has(object, 'a'); + * // => true + * + * _.has(object, 'a.b.c'); + * // => true + * + * _.has(object, ['a', 'b', 'c']); + * // => true + */ + function has(object, path) { + if (object == null) { + return false; + } + var result = hasOwnProperty.call(object, path); + if (!result && !isKey(path)) { + path = toPath(path); + object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1)); + if (object == null) { + return false; + } + path = last(path); + result = hasOwnProperty.call(object, path); + } + return result || (isLength(object.length) && isIndex(path, object.length) && + (isArray(object) || isArguments(object))); + } + + /** + * Creates an object composed of the inverted keys and values of `object`. + * If `object` contains duplicate values, subsequent values overwrite property + * assignments of previous values unless `multiValue` is `true`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to invert. + * @param {boolean} [multiValue] Allow multiple values per key. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {Object} Returns the new inverted object. + * @example + * + * var object = { 'a': 1, 'b': 2, 'c': 1 }; + * + * _.invert(object); + * // => { '1': 'c', '2': 'b' } + * + * // with `multiValue` + * _.invert(object, true); + * // => { '1': ['a', 'c'], '2': ['b'] } + */ + function invert(object, multiValue, guard) { + if (guard && isIterateeCall(object, multiValue, guard)) { + multiValue = undefined; + } + var index = -1, + props = keys(object), + length = props.length, + result = {}; + + while (++index < length) { + var key = props[index], + value = object[key]; + + if (multiValue) { + if (hasOwnProperty.call(result, value)) { + result[value].push(key); + } else { + result[value] = [key]; + } + } + else { + result[value] = key; + } + } + return result; + } + + /** + * Creates an array of the own enumerable property names of `object`. + * + * **Note:** Non-object values are coerced to objects. See the + * [ES spec](http://ecma-international.org/ecma-262/6.0/#sec-object.keys) + * for more details. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property names. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.keys(new Foo); + * // => ['a', 'b'] (iteration order is not guaranteed) + * + * _.keys('hi'); + * // => ['0', '1'] + */ + var keys = !nativeKeys ? shimKeys : function(object) { + var Ctor = object == null ? undefined : object.constructor; + if ((typeof Ctor == 'function' && Ctor.prototype === object) || + (typeof object != 'function' && isArrayLike(object))) { + return shimKeys(object); + } + return isObject(object) ? nativeKeys(object) : []; + }; + + /** + * Creates an array of the own and inherited enumerable property names of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property names. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.keysIn(new Foo); + * // => ['a', 'b', 'c'] (iteration order is not guaranteed) + */ + function keysIn(object) { + if (object == null) { + return []; + } + if (!isObject(object)) { + object = Object(object); + } + var length = object.length; + length = (length && isLength(length) && + (isArray(object) || isArguments(object)) && length) || 0; + + var Ctor = object.constructor, + index = -1, + isProto = typeof Ctor == 'function' && Ctor.prototype === object, + result = Array(length), + skipIndexes = length > 0; + + while (++index < length) { + result[index] = (index + ''); + } + for (var key in object) { + if (!(skipIndexes && isIndex(key, length)) && + !(key == 'constructor' && (isProto || !hasOwnProperty.call(object, key)))) { + result.push(key); + } + } + return result; + } + + /** + * The opposite of `_.mapValues`; this method creates an object with the + * same values as `object` and keys generated by running each own enumerable + * property of `object` through `iteratee`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the new mapped object. + * @example + * + * _.mapKeys({ 'a': 1, 'b': 2 }, function(value, key) { + * return key + value; + * }); + * // => { 'a1': 1, 'b2': 2 } + */ + var mapKeys = createObjectMapper(true); + + /** + * Creates an object with the same keys as `object` and values generated by + * running each own enumerable property of `object` through `iteratee`. The + * iteratee function is bound to `thisArg` and invoked with three arguments: + * (value, key, object). + * + * If a property name is provided for `iteratee` the created `_.property` + * style callback returns the property value of the given element. + * + * If a value is also provided for `thisArg` the created `_.matchesProperty` + * style callback returns `true` for elements that have a matching property + * value, else `false`. + * + * If an object is provided for `iteratee` the created `_.matches` style + * callback returns `true` for elements that have the properties of the given + * object, else `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to iterate over. + * @param {Function|Object|string} [iteratee=_.identity] The function invoked + * per iteration. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {Object} Returns the new mapped object. + * @example + * + * _.mapValues({ 'a': 1, 'b': 2 }, function(n) { + * return n * 3; + * }); + * // => { 'a': 3, 'b': 6 } + * + * var users = { + * 'fred': { 'user': 'fred', 'age': 40 }, + * 'pebbles': { 'user': 'pebbles', 'age': 1 } + * }; + * + * // using the `_.property` callback shorthand + * _.mapValues(users, 'age'); + * // => { 'fred': 40, 'pebbles': 1 } (iteration order is not guaranteed) + */ + var mapValues = createObjectMapper(); + + /** + * The opposite of `_.pick`; this method creates an object composed of the + * own and inherited enumerable properties of `object` that are not omitted. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {Function|...(string|string[])} [predicate] The function invoked per + * iteration or property names to omit, specified as individual property + * names or arrays of property names. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'user': 'fred', 'age': 40 }; + * + * _.omit(object, 'age'); + * // => { 'user': 'fred' } + * + * _.omit(object, _.isNumber); + * // => { 'user': 'fred' } + */ + var omit = restParam(function(object, props) { + if (object == null) { + return {}; + } + if (typeof props[0] != 'function') { + var props = arrayMap(baseFlatten(props), String); + return pickByArray(object, baseDifference(keysIn(object), props)); + } + var predicate = bindCallback(props[0], props[1], 3); + return pickByCallback(object, function(value, key, object) { + return !predicate(value, key, object); + }); + }); + + /** + * Creates a two dimensional array of the key-value pairs for `object`, + * e.g. `[[key1, value1], [key2, value2]]`. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the new array of key-value pairs. + * @example + * + * _.pairs({ 'barney': 36, 'fred': 40 }); + * // => [['barney', 36], ['fred', 40]] (iteration order is not guaranteed) + */ + function pairs(object) { + object = toObject(object); + + var index = -1, + props = keys(object), + length = props.length, + result = Array(length); + + while (++index < length) { + var key = props[index]; + result[index] = [key, object[key]]; + } + return result; + } + + /** + * Creates an object composed of the picked `object` properties. Property + * names may be specified as individual arguments or as arrays of property + * names. If `predicate` is provided it is invoked for each property of `object` + * picking the properties `predicate` returns truthy for. The predicate is + * bound to `thisArg` and invoked with three arguments: (value, key, object). + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The source object. + * @param {Function|...(string|string[])} [predicate] The function invoked per + * iteration or property names to pick, specified as individual property + * names or arrays of property names. + * @param {*} [thisArg] The `this` binding of `predicate`. + * @returns {Object} Returns the new object. + * @example + * + * var object = { 'user': 'fred', 'age': 40 }; + * + * _.pick(object, 'user'); + * // => { 'user': 'fred' } + * + * _.pick(object, _.isString); + * // => { 'user': 'fred' } + */ + var pick = restParam(function(object, props) { + if (object == null) { + return {}; + } + return typeof props[0] == 'function' + ? pickByCallback(object, bindCallback(props[0], props[1], 3)) + : pickByArray(object, baseFlatten(props)); + }); + + /** + * This method is like `_.get` except that if the resolved value is a function + * it is invoked with the `this` binding of its parent object and its result + * is returned. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @param {Array|string} path The path of the property to resolve. + * @param {*} [defaultValue] The value returned if the resolved value is `undefined`. + * @returns {*} Returns the resolved value. + * @example + * + * var object = { 'a': [{ 'b': { 'c1': 3, 'c2': _.constant(4) } }] }; + * + * _.result(object, 'a[0].b.c1'); + * // => 3 + * + * _.result(object, 'a[0].b.c2'); + * // => 4 + * + * _.result(object, 'a.b.c', 'default'); + * // => 'default' + * + * _.result(object, 'a.b.c', _.constant('default')); + * // => 'default' + */ + function result(object, path, defaultValue) { + var result = object == null ? undefined : object[path]; + if (result === undefined) { + if (object != null && !isKey(path, object)) { + path = toPath(path); + object = path.length == 1 ? object : baseGet(object, baseSlice(path, 0, -1)); + result = object == null ? undefined : object[last(path)]; + } + result = result === undefined ? defaultValue : result; + } + return isFunction(result) ? result.call(object) : result; + } + + /** + * Sets the property value of `path` on `object`. If a portion of `path` + * does not exist it is created. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to augment. + * @param {Array|string} path The path of the property to set. + * @param {*} value The value to set. + * @returns {Object} Returns `object`. + * @example + * + * var object = { 'a': [{ 'b': { 'c': 3 } }] }; + * + * _.set(object, 'a[0].b.c', 4); + * console.log(object.a[0].b.c); + * // => 4 + * + * _.set(object, 'x[0].y.z', 5); + * console.log(object.x[0].y.z); + * // => 5 + */ + function set(object, path, value) { + if (object == null) { + return object; + } + var pathKey = (path + ''); + path = (object[pathKey] != null || isKey(path, object)) ? [pathKey] : toPath(path); + + var index = -1, + length = path.length, + lastIndex = length - 1, + nested = object; + + while (nested != null && ++index < length) { + var key = path[index]; + if (isObject(nested)) { + if (index == lastIndex) { + nested[key] = value; + } else if (nested[key] == null) { + nested[key] = isIndex(path[index + 1]) ? [] : {}; + } + } + nested = nested[key]; + } + return object; + } + + /** + * An alternative to `_.reduce`; this method transforms `object` to a new + * `accumulator` object which is the result of running each of its own enumerable + * properties through `iteratee`, with each invocation potentially mutating + * the `accumulator` object. The `iteratee` is bound to `thisArg` and invoked + * with four arguments: (accumulator, value, key, object). Iteratee functions + * may exit iteration early by explicitly returning `false`. + * + * @static + * @memberOf _ + * @category Object + * @param {Array|Object} object The object to iterate over. + * @param {Function} [iteratee=_.identity] The function invoked per iteration. + * @param {*} [accumulator] The custom accumulator value. + * @param {*} [thisArg] The `this` binding of `iteratee`. + * @returns {*} Returns the accumulated value. + * @example + * + * _.transform([2, 3, 4], function(result, n) { + * result.push(n *= n); + * return n % 2 == 0; + * }); + * // => [4, 9] + * + * _.transform({ 'a': 1, 'b': 2 }, function(result, n, key) { + * result[key] = n * 3; + * }); + * // => { 'a': 3, 'b': 6 } + */ + function transform(object, iteratee, accumulator, thisArg) { + var isArr = isArray(object) || isTypedArray(object); + iteratee = getCallback(iteratee, thisArg, 4); + + if (accumulator == null) { + if (isArr || isObject(object)) { + var Ctor = object.constructor; + if (isArr) { + accumulator = isArray(object) ? new Ctor : []; + } else { + accumulator = baseCreate(isFunction(Ctor) ? Ctor.prototype : undefined); + } + } else { + accumulator = {}; + } + } + (isArr ? arrayEach : baseForOwn)(object, function(value, index, object) { + return iteratee(accumulator, value, index, object); + }); + return accumulator; + } + + /** + * Creates an array of the own enumerable property values of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property values. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.values(new Foo); + * // => [1, 2] (iteration order is not guaranteed) + * + * _.values('hi'); + * // => ['h', 'i'] + */ + function values(object) { + return baseValues(object, keys(object)); + } + + /** + * Creates an array of the own and inherited enumerable property values + * of `object`. + * + * **Note:** Non-object values are coerced to objects. + * + * @static + * @memberOf _ + * @category Object + * @param {Object} object The object to query. + * @returns {Array} Returns the array of property values. + * @example + * + * function Foo() { + * this.a = 1; + * this.b = 2; + * } + * + * Foo.prototype.c = 3; + * + * _.valuesIn(new Foo); + * // => [1, 2, 3] (iteration order is not guaranteed) + */ + function valuesIn(object) { + return baseValues(object, keysIn(object)); + } + + /*------------------------------------------------------------------------*/ + + /** + * Checks if `n` is between `start` and up to but not including, `end`. If + * `end` is not specified it is set to `start` with `start` then set to `0`. + * + * @static + * @memberOf _ + * @category Number + * @param {number} n The number to check. + * @param {number} [start=0] The start of the range. + * @param {number} end The end of the range. + * @returns {boolean} Returns `true` if `n` is in the range, else `false`. + * @example + * + * _.inRange(3, 2, 4); + * // => true + * + * _.inRange(4, 8); + * // => true + * + * _.inRange(4, 2); + * // => false + * + * _.inRange(2, 2); + * // => false + * + * _.inRange(1.2, 2); + * // => true + * + * _.inRange(5.2, 4); + * // => false + */ + function inRange(value, start, end) { + start = +start || 0; + if (end === undefined) { + end = start; + start = 0; + } else { + end = +end || 0; + } + return value >= nativeMin(start, end) && value < nativeMax(start, end); + } + + /** + * Produces a random number between `min` and `max` (inclusive). If only one + * argument is provided a number between `0` and the given number is returned. + * If `floating` is `true`, or either `min` or `max` are floats, a floating-point + * number is returned instead of an integer. + * + * @static + * @memberOf _ + * @category Number + * @param {number} [min=0] The minimum possible value. + * @param {number} [max=1] The maximum possible value. + * @param {boolean} [floating] Specify returning a floating-point number. + * @returns {number} Returns the random number. + * @example + * + * _.random(0, 5); + * // => an integer between 0 and 5 + * + * _.random(5); + * // => also an integer between 0 and 5 + * + * _.random(5, true); + * // => a floating-point number between 0 and 5 + * + * _.random(1.2, 5.2); + * // => a floating-point number between 1.2 and 5.2 + */ + function random(min, max, floating) { + if (floating && isIterateeCall(min, max, floating)) { + max = floating = undefined; + } + var noMin = min == null, + noMax = max == null; + + if (floating == null) { + if (noMax && typeof min == 'boolean') { + floating = min; + min = 1; + } + else if (typeof max == 'boolean') { + floating = max; + noMax = true; + } + } + if (noMin && noMax) { + max = 1; + noMax = false; + } + min = +min || 0; + if (noMax) { + max = min; + min = 0; + } else { + max = +max || 0; + } + if (floating || min % 1 || max % 1) { + var rand = nativeRandom(); + return nativeMin(min + (rand * (max - min + parseFloat('1e-' + ((rand + '').length - 1)))), max); + } + return baseRandom(min, max); + } + + /*------------------------------------------------------------------------*/ + + /** + * Converts `string` to [camel case](https://en.wikipedia.org/wiki/CamelCase). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the camel cased string. + * @example + * + * _.camelCase('Foo Bar'); + * // => 'fooBar' + * + * _.camelCase('--foo-bar'); + * // => 'fooBar' + * + * _.camelCase('__foo_bar__'); + * // => 'fooBar' + */ + var camelCase = createCompounder(function(result, word, index) { + word = word.toLowerCase(); + return result + (index ? (word.charAt(0).toUpperCase() + word.slice(1)) : word); + }); + + /** + * Capitalizes the first character of `string`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to capitalize. + * @returns {string} Returns the capitalized string. + * @example + * + * _.capitalize('fred'); + * // => 'Fred' + */ + function capitalize(string) { + string = baseToString(string); + return string && (string.charAt(0).toUpperCase() + string.slice(1)); + } + + /** + * Deburrs `string` by converting [latin-1 supplementary letters](https://en.wikipedia.org/wiki/Latin-1_Supplement_(Unicode_block)#Character_table) + * to basic latin letters and removing [combining diacritical marks](https://en.wikipedia.org/wiki/Combining_Diacritical_Marks). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to deburr. + * @returns {string} Returns the deburred string. + * @example + * + * _.deburr('déjà vu'); + * // => 'deja vu' + */ + function deburr(string) { + string = baseToString(string); + return string && string.replace(reLatin1, deburrLetter).replace(reComboMark, ''); + } + + /** + * Checks if `string` ends with the given target string. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to search. + * @param {string} [target] The string to search for. + * @param {number} [position=string.length] The position to search from. + * @returns {boolean} Returns `true` if `string` ends with `target`, else `false`. + * @example + * + * _.endsWith('abc', 'c'); + * // => true + * + * _.endsWith('abc', 'b'); + * // => false + * + * _.endsWith('abc', 'b', 2); + * // => true + */ + function endsWith(string, target, position) { + string = baseToString(string); + target = (target + ''); + + var length = string.length; + position = position === undefined + ? length + : nativeMin(position < 0 ? 0 : (+position || 0), length); + + position -= target.length; + return position >= 0 && string.indexOf(target, position) == position; + } + + /** + * Converts the characters "&", "<", ">", '"', "'", and "\`", in `string` to + * their corresponding HTML entities. + * + * **Note:** No other characters are escaped. To escape additional characters + * use a third-party library like [_he_](https://mths.be/he). + * + * Though the ">" character is escaped for symmetry, characters like + * ">" and "/" don't need escaping in HTML and have no special meaning + * unless they're part of a tag or unquoted attribute value. + * See [Mathias Bynens's article](https://mathiasbynens.be/notes/ambiguous-ampersands) + * (under "semi-related fun fact") for more details. + * + * Backticks are escaped because in Internet Explorer < 9, they can break out + * of attribute values or HTML comments. See [#59](https://html5sec.org/#59), + * [#102](https://html5sec.org/#102), [#108](https://html5sec.org/#108), and + * [#133](https://html5sec.org/#133) of the [HTML5 Security Cheatsheet](https://html5sec.org/) + * for more details. + * + * When working with HTML you should always [quote attribute values](http://wonko.com/post/html-escaping) + * to reduce XSS vectors. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escape('fred, barney, & pebbles'); + * // => 'fred, barney, & pebbles' + */ + function escape(string) { + // Reset `lastIndex` because in IE < 9 `String#replace` does not. + string = baseToString(string); + return (string && reHasUnescapedHtml.test(string)) + ? string.replace(reUnescapedHtml, escapeHtmlChar) + : string; + } + + /** + * Escapes the `RegExp` special characters "\", "/", "^", "$", ".", "|", "?", + * "*", "+", "(", ")", "[", "]", "{" and "}" in `string`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to escape. + * @returns {string} Returns the escaped string. + * @example + * + * _.escapeRegExp('[lodash](https://lodash.com/)'); + * // => '\[lodash\]\(https:\/\/lodash\.com\/\)' + */ + function escapeRegExp(string) { + string = baseToString(string); + return (string && reHasRegExpChars.test(string)) + ? string.replace(reRegExpChars, escapeRegExpChar) + : (string || '(?:)'); + } + + /** + * Converts `string` to [kebab case](https://en.wikipedia.org/wiki/Letter_case#Special_case_styles). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the kebab cased string. + * @example + * + * _.kebabCase('Foo Bar'); + * // => 'foo-bar' + * + * _.kebabCase('fooBar'); + * // => 'foo-bar' + * + * _.kebabCase('__foo_bar__'); + * // => 'foo-bar' + */ + var kebabCase = createCompounder(function(result, word, index) { + return result + (index ? '-' : '') + word.toLowerCase(); + }); + + /** + * Pads `string` on the left and right sides if it's shorter than `length`. + * Padding characters are truncated if they can't be evenly divided by `length`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.pad('abc', 8); + * // => ' abc ' + * + * _.pad('abc', 8, '_-'); + * // => '_-abc_-_' + * + * _.pad('abc', 3); + * // => 'abc' + */ + function pad(string, length, chars) { + string = baseToString(string); + length = +length; + + var strLength = string.length; + if (strLength >= length || !nativeIsFinite(length)) { + return string; + } + var mid = (length - strLength) / 2, + leftLength = nativeFloor(mid), + rightLength = nativeCeil(mid); + + chars = createPadding('', rightLength, chars); + return chars.slice(0, leftLength) + string + chars; + } + + /** + * Pads `string` on the left side if it's shorter than `length`. Padding + * characters are truncated if they exceed `length`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.padLeft('abc', 6); + * // => ' abc' + * + * _.padLeft('abc', 6, '_-'); + * // => '_-_abc' + * + * _.padLeft('abc', 3); + * // => 'abc' + */ + var padLeft = createPadDir(); + + /** + * Pads `string` on the right side if it's shorter than `length`. Padding + * characters are truncated if they exceed `length`. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to pad. + * @param {number} [length=0] The padding length. + * @param {string} [chars=' '] The string used as padding. + * @returns {string} Returns the padded string. + * @example + * + * _.padRight('abc', 6); + * // => 'abc ' + * + * _.padRight('abc', 6, '_-'); + * // => 'abc_-_' + * + * _.padRight('abc', 3); + * // => 'abc' + */ + var padRight = createPadDir(true); + + /** + * Converts `string` to an integer of the specified radix. If `radix` is + * `undefined` or `0`, a `radix` of `10` is used unless `value` is a hexadecimal, + * in which case a `radix` of `16` is used. + * + * **Note:** This method aligns with the [ES5 implementation](https://es5.github.io/#E) + * of `parseInt`. + * + * @static + * @memberOf _ + * @category String + * @param {string} string The string to convert. + * @param {number} [radix] The radix to interpret `value` by. + * @param- {Object} [guard] Enables use as a callback for functions like `_.map`. + * @returns {number} Returns the converted integer. + * @example + * + * _.parseInt('08'); + * // => 8 + * + * _.map(['6', '08', '10'], _.parseInt); + * // => [6, 8, 10] + */ + function parseInt(string, radix, guard) { + // Firefox < 21 and Opera < 15 follow ES3 for `parseInt`. + // Chrome fails to trim leading whitespace characters. + // See https://code.google.com/p/v8/issues/detail?id=3109 for more details. + if (guard ? isIterateeCall(string, radix, guard) : radix == null) { + radix = 0; + } else if (radix) { + radix = +radix; + } + string = trim(string); + return nativeParseInt(string, radix || (reHasHexPrefix.test(string) ? 16 : 10)); + } + + /** + * Repeats the given string `n` times. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to repeat. + * @param {number} [n=0] The number of times to repeat the string. + * @returns {string} Returns the repeated string. + * @example + * + * _.repeat('*', 3); + * // => '***' + * + * _.repeat('abc', 2); + * // => 'abcabc' + * + * _.repeat('abc', 0); + * // => '' + */ + function repeat(string, n) { + var result = ''; + string = baseToString(string); + n = +n; + if (n < 1 || !string || !nativeIsFinite(n)) { + return result; + } + // Leverage the exponentiation by squaring algorithm for a faster repeat. + // See https://en.wikipedia.org/wiki/Exponentiation_by_squaring for more details. + do { + if (n % 2) { + result += string; + } + n = nativeFloor(n / 2); + string += string; + } while (n); + + return result; + } + + /** + * Converts `string` to [snake case](https://en.wikipedia.org/wiki/Snake_case). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the snake cased string. + * @example + * + * _.snakeCase('Foo Bar'); + * // => 'foo_bar' + * + * _.snakeCase('fooBar'); + * // => 'foo_bar' + * + * _.snakeCase('--foo-bar'); + * // => 'foo_bar' + */ + var snakeCase = createCompounder(function(result, word, index) { + return result + (index ? '_' : '') + word.toLowerCase(); + }); + + /** + * Converts `string` to [start case](https://en.wikipedia.org/wiki/Letter_case#Stylistic_or_specialised_usage). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to convert. + * @returns {string} Returns the start cased string. + * @example + * + * _.startCase('--foo-bar'); + * // => 'Foo Bar' + * + * _.startCase('fooBar'); + * // => 'Foo Bar' + * + * _.startCase('__foo_bar__'); + * // => 'Foo Bar' + */ + var startCase = createCompounder(function(result, word, index) { + return result + (index ? ' ' : '') + (word.charAt(0).toUpperCase() + word.slice(1)); + }); + + /** + * Checks if `string` starts with the given target string. + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The string to search. + * @param {string} [target] The string to search for. + * @param {number} [position=0] The position to search from. + * @returns {boolean} Returns `true` if `string` starts with `target`, else `false`. + * @example + * + * _.startsWith('abc', 'a'); + * // => true + * + * _.startsWith('abc', 'b'); + * // => false + * + * _.startsWith('abc', 'b', 1); + * // => true + */ + function startsWith(string, target, position) { + string = baseToString(string); + position = position == null + ? 0 + : nativeMin(position < 0 ? 0 : (+position || 0), string.length); + + return string.lastIndexOf(target, position) == position; + } + + /** + * Creates a compiled template function that can interpolate data properties + * in "interpolate" delimiters, HTML-escape interpolated data properties in + * "escape" delimiters, and execute JavaScript in "evaluate" delimiters. Data + * properties may be accessed as free variables in the template. If a setting + * object is provided it takes precedence over `_.templateSettings` values. + * + * **Note:** In the development build `_.template` utilizes + * [sourceURLs](http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl) + * for easier debugging. + * + * For more information on precompiling templates see + * [lodash's custom builds documentation](https://lodash.com/custom-builds). + * + * For more information on Chrome extension sandboxes see + * [Chrome's extensions documentation](https://developer.chrome.com/extensions/sandboxingEval). + * + * @static + * @memberOf _ + * @category String + * @param {string} [string=''] The template string. + * @param {Object} [options] The options object. + * @param {RegExp} [options.escape] The HTML "escape" delimiter. + * @param {RegExp} [options.evaluate] The "evaluate" delimiter. + * @param {Object} [options.imports] An object to import into the template as free variables. + * @param {RegExp} [options.interpolate] The "interpolate" delimiter. + * @param {string} [options.sourceURL] The sourceURL of the template's compiled source. + * @param {string} [options.variable] The data object variable name. + * @param- {Object} [otherOptions] Enables the legacy `options` param signature. + * @returns {Function} Returns the compiled template function. + * @example + * + * // using the "interpolate" delimiter to create a compiled template + * var compiled = _.template('hello <%= user %>!'); + * compiled({ 'user': 'fred' }); + * // => 'hello fred!' + * + * // using the HTML "escape" delimiter to escape data property values + * var compiled = _.template('<%- value %>'); + * compiled({ 'value': '