/*!
* Lo-Dash v0.5.2 <http://lodash.com>
* Copyright 2012 John-David Dalton <http://allyoucanleet.com/>
* Based on Underscore.js 1.3.3, copyright 2009-2012 Jeremy Ashkenas, DocumentCloud Inc.
* <http://documentcloud.github.com/underscore>
* Available under MIT license <http://lodash.com/license>
*/
;(function(window, undefined) {
'use strict';
/**
* Used to cache the last `_.templateSettings.evaluate` delimiter to avoid
* unnecessarily assigning `reEvaluateDelimiter` a new generated regexp.
* Assigned in `_.template`.
*/
var lastEvaluateDelimiter;
/**
* Used to cache the last template `options.variable` to avoid unnecessarily
* assigning `reDoubleVariable` a new generated regexp. Assigned in `_.template`.
*/
var lastVariable;
/**
* Used to match potentially incorrect data object references, like `obj.obj`,
* in compiled templates. Assigned in `_.template`.
*/
var reDoubleVariable;
/**
* Used to match "evaluate" delimiters, including internal delimiters,
* in template text. Assigned in `_.template`.
*/
var reEvaluateDelimiter;
/** Detect free variable `exports` */
var freeExports = typeof exports == 'object' && exports &&
(typeof global == 'object' && global && global == global.global && (window = global), exports);
/** Native prototype shortcuts */
var ArrayProto = Array.prototype,
BoolProto = Boolean.prototype,
ObjectProto = Object.prototype,
NumberProto = Number.prototype,
StringProto = String.prototype;
/** Used to generate unique IDs */
var idCounter = 0;
/** Used to restore the original `_` reference in `noConflict` */
var oldDash = window._;
/** Used to detect delimiter values that should be processed by `tokenizeEvaluate` */
var reComplexDelimiter = /[-+=!~*%&^<>|{(\/]|\[\D|\b(?:delete|in|instanceof|new|typeof|void)\b/;
/** 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 regexp flags from their coerced string values */
var reFlags = /\w*$/;
/** Used to insert the data object variable into compiled template source */
var reInsertVariable = /(?:__e|__t = )\(\s*(?![\d\s"']|this\.)/g;
/** Used to detect if a method is native */
var reNative = RegExp('^' +
(ObjectProto.valueOf + '')
.replace(/[.*+?^=!:${}()|[\]\/\\]/g, '\\$&')
.replace(/valueOf|for [^\]]+/g, '.+?') + '$'
);
/** Used to match tokens in template text */
var reToken = /__token__(\d+)/g;
/** Used to match unescaped characters in strings for inclusion in HTML */
var reUnescapedHtml = /[&<"']/g;
/** Used to match unescaped characters in compiled string literals */
var reUnescapedString = /['\n\r\t\u2028\u2029\\]/g;
/** Used to fix the JScript [[DontEnum]] bug */
var shadowed = [
'constructor', 'hasOwnProperty', 'isPrototypeOf', 'propertyIsEnumerable',
'toLocaleString', 'toString', 'valueOf'
];
/** Used to make template sourceURLs easier to identify */
var templateCounter = 0;
/** Used to replace template delimiters */
var token = '__token__';
/** Used to store tokenized template text snippets */
var tokenized = [];
/** Native method shortcuts */
var concat = ArrayProto.concat,
hasOwnProperty = ObjectProto.hasOwnProperty,
push = ArrayProto.push,
propertyIsEnumerable = ObjectProto.propertyIsEnumerable,
slice = ArrayProto.slice,
toString = ObjectProto.toString;
/* Native method shortcuts for methods with the same name as other `lodash` methods */
var nativeBind = reNative.test(nativeBind = slice.bind) && nativeBind,
nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
nativeIsFinite = window.isFinite,
nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys;
/** `Object#toString` result shortcuts */
var argsClass = '[object Arguments]',
arrayClass = '[object Array]',
boolClass = '[object Boolean]',
dateClass = '[object Date]',
funcClass = '[object Function]',
numberClass = '[object Number]',
objectClass = '[object Object]',
regexpClass = '[object RegExp]',
stringClass = '[object String]';
/** Timer shortcuts */
var clearTimeout = window.clearTimeout,
setTimeout = window.setTimeout;
/**
* Detect the JScript [[DontEnum]] bug:
* In IE < 9 an objects own properties, shadowing non-enumerable ones, are
* made non-enumerable as well.
*/
var hasDontEnumBug;
/** Detect if own properties are iterated after inherited properties (IE < 9) */
var iteratesOwnLast;
/** Detect if an `arguments` object's indexes are non-enumerable (IE < 9) */
var noArgsEnum = true;
(function() {
var props = [];
function ctor() { this.x = 1; }
ctor.prototype = { 'valueOf': 1, 'y': 1 };
for (var prop in new ctor) { props.push(prop); }
for (prop in arguments) { noArgsEnum = !prop; }
hasDontEnumBug = (props + '').length < 4;
iteratesOwnLast = props[0] != 'x';
}(1));
/** Detect if an `arguments` object's [[Class]] is unresolvable (Firefox < 4, IE < 9) */
var noArgsClass = !isArguments(arguments);
/** Detect if `Array#slice` cannot be used to convert strings to arrays (Opera < 10.52) */
var noArraySliceOnStrings = slice.call('x')[0] != 'x';
/**
* Detect lack of support for accessing string characters by index:
* IE < 8 can't access characters by index and IE 8 can only access
* characters by index on string literals.
*/
var noCharByIndex = ('x'[0] + Object('x')[0]) != 'xx';
/**
* Detect if a node's [[Class]] is unresolvable (IE < 9)
* and that the JS engine won't error when attempting to coerce an object to
* a string without a `toString` property value of `typeof` "function".
*/
try {
var noNodeClass = ({ 'toString': 0 } + '', toString.call(window.document || 0) == objectClass);
} catch(e) { }
/* Detect if `Function#bind` exists and is inferred to be fast (all but V8) */
var isBindFast = nativeBind && /\n|Opera/.test(nativeBind + toString.call(window.opera));
/* Detect if `Object.keys` exists and is inferred to be fast (IE, Opera, V8) */
var isKeysFast = nativeKeys && /^.+$|true/.test(nativeKeys + !!window.attachEvent);
/** Detect if sourceURL syntax is usable without erroring */
try {
// The JS engine in Adobe products, like InDesign, will throw a syntax error
// when it encounters a single line comment beginning with the `@` symbol.
// The JS engine in Narwhal will generate the function `function anonymous(){//}`
// and throw a syntax error. In IE, `@` symbols are part of its non-standard
// conditional compilation support. The `@cc_on` statement activates its support
// while the trailing ` !` induces a syntax error to exlude it. Compatibility
// modes in IE > 8 require a space before the `!` to induce a syntax error.
// See http://msdn.microsoft.com/en-us/library/121hztk3(v=vs.94).aspx
var useSourceURL = (Function('//@cc_on !')(), true);
} catch(e){ }
/** Used to identify object classifications that are array-like */
var arrayLikeClasses = {};
arrayLikeClasses[boolClass] = arrayLikeClasses[dateClass] = arrayLikeClasses[funcClass] =
arrayLikeClasses[numberClass] = arrayLikeClasses[objectClass] = arrayLikeClasses[regexpClass] = false;
arrayLikeClasses[argsClass] = arrayLikeClasses[arrayClass] = arrayLikeClasses[stringClass] = true;
/** Used to identify object classifications that `_.clone` supports */
var cloneableClasses = {};
cloneableClasses[argsClass] = cloneableClasses[funcClass] = false;
cloneableClasses[arrayClass] = cloneableClasses[boolClass] = cloneableClasses[dateClass] =
cloneableClasses[numberClass] = cloneableClasses[objectClass] = cloneableClasses[regexpClass] =
cloneableClasses[stringClass] = true;
/**
* Used to escape characters for inclusion in HTML.
* The `>` and `/` characters don't require escaping in HTML and have no
* special meaning unless they're part of a tag or an unquoted attribute value
* http://mathiasbynens.be/notes/ambiguous-ampersands (semi-related fun fact)
*/
var htmlEscapes = {
'&': '&',
'<': '<',
'"': '"',
"'": '''
};
/** Used to determine if values are of the language type Object */
var objectTypes = {
'boolean': false,
'function': true,
'object': true,
'number': false,
'string': false,
'undefined': false,
'unknown': true
};
/** Used to escape characters for inclusion in compiled string literals */
var stringEscapes = {
'\\': '\\',
"'": "'",
'\n': 'n',
'\r': 'r',
'\t': 't',
'\u2028': 'u2028',
'\u2029': 'u2029'
};
/*--------------------------------------------------------------------------*/
/**
* The `lodash` function.
*
* @name _
* @constructor
* @param {Mixed} value The value to wrap in a `LoDash` instance.
* @returns {Object} Returns a `LoDash` instance.
*/
function lodash(value) {
// allow invoking `lodash` without the `new` operator
return new LoDash(value);
}
/**
* Creates a `LoDash` instance that wraps a value to allow chaining.
*
* @private
* @constructor
* @param {Mixed} value The value to wrap.
*/
function LoDash(value) {
// exit early if already wrapped
if (value && value._wrapped) {
return value;
}
this._wrapped = value;
}
/**
* By default, the template delimiters used by Lo-Dash are similar to 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.
*
* @static
* @memberOf _.templateSettings
* @type RegExp
*/
'escape': /<%-([\s\S]+?)%>/g,
/**
* Used to detect code to be evaluated.
*
* @static
* @memberOf _.templateSettings
* @type RegExp
*/
'evaluate': /<%([\s\S]+?)%>/g,
/**
* Used to detect `data` property values to inject.
*
* @static
* @memberOf _.templateSettings
* @type RegExp
*/
'interpolate': /<%=([\s\S]+?)%>/g,
/**
* Used to reference the data object in the template text.
*
* @static
* @memberOf _.templateSettings
* @type String
*/
'variable': ''
};
/*--------------------------------------------------------------------------*/
/**
* The template used to create iterator functions.
*
* @private
* @param {Obect} data The data object used to populate the text.
* @returns {String} Returns the interpolated text.
*/
var iteratorTemplate = template(
// conditional strict mode
'<% if (useStrict) { %>\'use strict\';\n<% } %>' +
// the `iteratee` may be reassigned by the `top` snippet
'var index, value, iteratee = <%= firstArg %>, ' +
// assign the `result` variable an initial value
'result<% if (init) { %> = <%= init %><% } %>;\n' +
// add code to exit early or do so if the first argument is falsey
'<%= exit %>;\n' +
// add code after the exit snippet but before the iteration branches
'<%= top %>;\n' +
// the following branch is for iterating arrays and array-like objects
'<% if (arrayBranch) { %>' +
'var length = iteratee.length; index = -1;' +
' <% if (objectBranch) { %>\nif (length > -1 && length === length >>> 0) {<% } %>' +
// add support for accessing string characters by index if needed
' <% if (noCharByIndex) { %>\n' +
' if (toString.call(iteratee) == stringClass) {\n' +
' iteratee = iteratee.split(\'\')\n' +
' }' +
' <% } %>\n' +
' <%= arrayBranch.beforeLoop %>;\n' +
' while (++index < length) {\n' +
' value = iteratee[index];\n' +
' <%= arrayBranch.inLoop %>\n' +
' }' +
' <% if (objectBranch) { %>\n}<% } %>' +
'<% } %>' +
// the following branch is for iterating an object's own/inherited properties
'<% if (objectBranch) { %>' +
' <% if (arrayBranch) { %>\nelse {' +
// add support for iterating over `arguments` objects if needed
' <% } else if (noArgsEnum) { %>\n' +
' var length = iteratee.length; index = -1;\n' +
' if (length && isArguments(iteratee)) {\n' +
' while (++index < length) {\n' +
' value = iteratee[index += \'\'];\n' +
' <%= objectBranch.inLoop %>\n' +
' }\n' +
' } else {' +
' <% } %>' +
' <% if (!hasDontEnumBug) { %>\n' +
' var skipProto = typeof iteratee == \'function\' && \n' +
' propertyIsEnumerable.call(iteratee, \'prototype\');\n' +
' <% } %>' +
// iterate own properties using `Object.keys` if it's fast
' <% if (isKeysFast && useHas) { %>\n' +
' var ownIndex = -1,\n' +
' ownProps = objectTypes[typeof iteratee] ? nativeKeys(iteratee) : [],\n' +
' length = ownProps.length;\n\n' +
' <%= objectBranch.beforeLoop %>;\n' +
' while (++ownIndex < length) {\n' +
' index = ownProps[ownIndex];\n' +
' <% if (!hasDontEnumBug) { %>if (!(skipProto && index == \'prototype\')) {\n <% } %>' +
' value = iteratee[index];\n' +
' <%= objectBranch.inLoop %>\n' +
' <% if (!hasDontEnumBug) { %>}\n<% } %>' +
' }' +
// else using a for-in loop
' <% } else { %>\n' +
' <%= objectBranch.beforeLoop %>;\n' +
' for (index in iteratee) {' +
' <% if (hasDontEnumBug) { %>\n' +
' <% if (useHas) { %>if (hasOwnProperty.call(iteratee, index)) {\n <% } %>' +
' value = iteratee[index];\n' +
' <%= objectBranch.inLoop %>;\n' +
' <% if (useHas) { %>}<% } %>' +
// Firefox < 3.6, Opera > 9.50 - Opera < 11.60, and Safari < 5.1
// (if the prototype or a property on the prototype has been set)
// incorrectly sets a function's `prototype` property [[Enumerable]]
// value to `true`. Because of this Lo-Dash standardizes on skipping
// the the `prototype` property of functions regardless of its
// [[Enumerable]] value.
' <% } else { %>\n' +
' if (!(skipProto && index == \'prototype\')<% if (useHas) { %> &&\n' +
' hasOwnProperty.call(iteratee, index)<% } %>) {\n' +
' value = iteratee[index];\n' +
' <%= objectBranch.inLoop %>\n' +
' }' +
' <% } %>\n' +
' }' +
' <% } %>' +
// Because IE < 9 can't set the `[[Enumerable]]` attribute of an
// existing property and the `constructor` property of a prototype
// defaults to non-enumerable, Lo-Dash skips the `constructor`
// property when it infers it's iterating over a `prototype` object.
' <% if (hasDontEnumBug) { %>\n\n' +
' var ctor = iteratee.constructor;\n' +
' <% for (var k = 0; k < 7; k++) { %>\n' +
' index = \'<%= shadowed[k] %>\';\n' +
' if (<%' +
' if (shadowed[k] == \'constructor\') {' +
' %>!(ctor && ctor.prototype === iteratee) && <%' +
' } %>hasOwnProperty.call(iteratee, index)) {\n' +
' value = iteratee[index];\n' +
' <%= objectBranch.inLoop %>\n' +
' }' +
' <% } %>' +
' <% } %>' +
' <% if (arrayBranch || noArgsEnum) { %>\n}<% } %>' +
'<% } %>\n' +
// add code to the bottom of the iteration function
'<%= bottom %>;\n' +
// finally, return the `result`
'return result'
);
/**
* Reusable iterator options shared by
* `every`, `filter`, `find`, `forEach`, `forIn`, `forOwn`, `groupBy`, `map`,
* `reject`, `some`, and `sortBy`.
*/
var baseIteratorOptions = {
'args': 'collection, callback, thisArg',
'init': 'collection',
'top':
'if (!callback) {\n' +
' callback = identity\n' +
'}\n' +
'else if (thisArg) {\n' +
' callback = iteratorBind(callback, thisArg)\n' +
'}',
'inLoop': 'if (callback(value, index, collection) === false) return result'
};
/** Reusable iterator options for `countBy`, `groupBy`, and `sortBy` */
var countByIteratorOptions = {
'init': '{}',
'top':
'var prop;\n' +
'if (typeof callback != \'function\') {\n' +
' var valueProp = callback;\n' +
' callback = function(value) { return value[valueProp] }\n' +
'}\n' +
'else if (thisArg) {\n' +
' callback = iteratorBind(callback, thisArg)\n' +
'}',
'inLoop':
'prop = callback(value, index, collection);\n' +
'(hasOwnProperty.call(result, prop) ? result[prop]++ : result[prop] = 1)'
};
/** Reusable iterator options for `every` and `some` */
var everyIteratorOptions = {
'init': 'true',
'inLoop': 'if (!callback(value, index, collection)) return !result'
};
/** Reusable iterator options for `defaults` and `extend` */
var extendIteratorOptions = {
'useHas': false,
'useStrict': false,
'args': 'object',
'init': 'object',
'top':
'for (var argsIndex = 1, argsLength = arguments.length; argsIndex < argsLength; argsIndex++) {\n' +
' if (iteratee = arguments[argsIndex]) {',
'inLoop': 'result[index] = value',
'bottom': ' }\n}'
};
/** Reusable iterator options for `filter`, `reject`, and `where` */
var filterIteratorOptions = {
'init': '[]',
'inLoop': 'callback(value, index, collection) && result.push(value)'
};
/** Reusable iterator options for `find`, `forEach`, `forIn`, and `forOwn` */
var forEachIteratorOptions = {
'top': 'if (thisArg) callback = iteratorBind(callback, thisArg)'
};
/** Reusable iterator options for `forIn` and `forOwn` */
var forOwnIteratorOptions = {
'inLoop': {
'object': baseIteratorOptions.inLoop
}
};
/** Reusable iterator options for `invoke`, `map`, `pluck`, and `sortBy` */
var mapIteratorOptions = {
'init': '',
'exit': 'if (!collection) return []',
'beforeLoop': {
'array': 'result = Array(length)',
'object': 'result = ' + (isKeysFast ? 'Array(length)' : '[]')
},
'inLoop': {
'array': 'result[index] = callback(value, index, collection)',
'object': 'result' + (isKeysFast ? '[ownIndex] = ' : '.push') + '(callback(value, index, collection))'
}
};
/*--------------------------------------------------------------------------*/
/**
* Creates a new function optimized for searching large arrays for a given `value`,
* starting at `fromIndex`, using strict equality for comparisons, i.e. `===`.
*
* @private
* @param {Array} array The array to search.
* @param {Mixed} value The value to search for.
* @param {Number} [fromIndex=0] The index to start searching from.
* @param {Number} [largeSize=30] The length at which an array is considered large.
* @returns {Boolean} Returns `true` if `value` is found, else `false`.
*/
function cachedContains(array, fromIndex, largeSize) {
fromIndex || (fromIndex = 0);
var length = array.length,
isLarge = (length - fromIndex) >= (largeSize || 30),
cache = isLarge ? {} : array;
if (isLarge) {
// init value cache
var key,
index = fromIndex - 1;
while (++index < length) {
// manually coerce `value` to string because `hasOwnProperty`, in some
// older versions of Firefox, coerces objects incorrectly
key = array[index] + '';
(hasOwnProperty.call(cache, key) ? cache[key] : (cache[key] = [])).push(array[index]);
}
}
return function(value) {
if (isLarge) {
var key = value + '';
return hasOwnProperty.call(cache, key) && indexOf(cache[key], value) > -1;
}
return indexOf(cache, value, fromIndex) > -1;
}
}
/**
* Creates compiled iteration functions. The iteration function will be created
* to iterate over only objects if the first argument of `options.args` is
* "object" or `options.inLoop.array` is falsey.
*
* @private
* @param {Object} [options1, options2, ...] The compile options objects.
*
* useHas - A boolean to specify whether or not to use `hasOwnProperty` checks
* in the object loop.
*
* useStrict - A boolean to specify whether or not to include the ES5
* "use strict" directive.
*
* args - A string of comma separated arguments the iteration function will
* accept.
*
* init - A string to specify the initial value of the `result` variable.
*
* exit - A string of code to use in place of the default exit-early check
* of `if (!arguments[0]) return result`.
*
* top - A string of code to execute after the exit-early check but before
* the iteration branches.
*
* beforeLoop - A string or object containing an "array" or "object" property
* of code to execute before the array or object loops.
*
* inLoop - A string or object containing an "array" or "object" property
* of code to execute in the array or object loops.
*
* bottom - A string of code to execute after the iteration branches but
* before the `result` is returned.
*
* @returns {Function} Returns the compiled function.
*/
function createIterator() {
var object,
prop,
value,
index = -1,
length = arguments.length;
// merge options into a template data object
var data = {
'bottom': '',
'exit': '',
'init': '',
'top': '',
'arrayBranch': { 'beforeLoop': '' },
'objectBranch': { 'beforeLoop': '' }
};
while (++index < length) {
object = arguments[index];
for (prop in object) {
value = (value = object[prop]) == null ? '' : value;
// keep this regexp explicit for the build pre-process
if (/beforeLoop|inLoop/.test(prop)) {
if (typeof value == 'string') {
value = { 'array': value, 'object': value };
}
data.arrayBranch[prop] = value.array;
data.objectBranch[prop] = value.object;
} else {
data[prop] = value;
}
}
}
// set additional template `data` values
var args = data.args,
firstArg = /^[^,]+/.exec(args)[0];
data.firstArg = firstArg;
data.hasDontEnumBug = hasDontEnumBug;
data.isKeysFast = isKeysFast;
data.noArgsEnum = noArgsEnum;
data.shadowed = shadowed;
data.useHas = data.useHas !== false;
data.useStrict = data.useStrict !== false;
if (!('noCharByIndex' in data)) {
data.noCharByIndex = noCharByIndex;
}
if (!data.exit) {
data.exit = 'if (!' + firstArg + ') return result';
}
if (firstArg != 'collection' || !data.arrayBranch.inLoop) {
data.arrayBranch = null;
}
// create the function factory
var factory = Function(
'arrayLikeClasses, ArrayProto, bind, compareAscending, concat, forIn, ' +
'hasOwnProperty, identity, indexOf, isArguments, isArray, isFunction, ' +
'isPlainObject, iteratorBind, objectClass, objectTypes, nativeKeys, ' +
'propertyIsEnumerable, slice, stringClass, toString',
'var callee = function(' + args + ') {\n' + iteratorTemplate(data) + '\n};\n' +
'return callee'
);
// return the compiled function
return factory(
arrayLikeClasses, ArrayProto, bind, compareAscending, concat, forIn,
hasOwnProperty, identity, indexOf, isArguments, isArray, isFunction,
isPlainObject, iteratorBind, objectClass, objectTypes, nativeKeys,
propertyIsEnumerable, slice, stringClass, toString
);
}
/**
* Used by `sortBy` to compare transformed `collection` values, stable sorting
* them in ascending order.
*
* @private
* @param {Object} a The object to compare to `b`.
* @param {Object} b The object to compare to `a`.
* @returns {Number} Returns the sort order indicator of `1` or `-1`.
*/
function compareAscending(a, b) {
var ai = a.index,
bi = b.index;
a = a.criteria;
b = b.criteria;
if (a === undefined) {
return 1;
}
if (b === undefined) {
return -1;
}
// ensure a stable sort in V8 and other engines
// http://code.google.com/p/v8/issues/detail?id=90
return a < b ? -1 : a > b ? 1 : ai < bi ? -1 : 1;
}
/**
* Used by `template` to replace tokens with their corresponding code snippets.
*
* @private
* @param {String} match The matched token.
* @param {String} index The `tokenized` index of the code snippet.
* @returns {String} Returns the code snippet.
*/
function detokenize(match, index) {
return tokenized[index];
}
/**
* Used by `template` to escape characters for inclusion in compiled
* string literals.
*
* @private
* @param {String} match The matched character to escape.
* @returns {String} Returns the escaped character.
*/
function escapeStringChar(match) {
return '\\' + stringEscapes[match];
}
/**
* Used by `escape` to escape characters for inclusion in HTML.
*
* @private
* @param {String} match The matched character to escape.
* @returns {String} Returns the escaped character.
*/
function escapeHtmlChar(match) {
return htmlEscapes[match];
}
/**
* Checks if a given `value` is an object created by the `Object` constructor
* assuming objects created by the `Object` constructor have no inherited
* enumerable properties and that there are no `Object.prototype` extensions.
*
* @private
* @param {Mixed} value The value to check.
* @param {Boolean} [skipArgsCheck=false] Internally used to skip checks for
* `arguments` objects.
* @returns {Boolean} Returns `true` if the `value` is a plain `Object` object,
* else `false`.
*/
function isPlainObject(value, skipArgsCheck) {
// avoid non-objects and false positives for `arguments` objects
var result = false;
if (!(value && typeof value == 'object') || (!skipArgsCheck && isArguments(value))) {
return result;
}
// IE < 9 presents DOM nodes as `Object` objects except they have `toString`
// methods that are `typeof` "string" and still can coerce nodes to strings.
// Also check that the constructor is `Object` (i.e. `Object instanceof Object`)
var ctor = value.constructor;
if ((!noNodeClass || !(typeof value.toString != 'function' && typeof (value + '') == 'string')) &&
(!isFunction(ctor) || ctor instanceof ctor)) {
// 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.
if (iteratesOwnLast) {
forIn(value, function(objValue, objKey) {
result = !hasOwnProperty.call(value, objKey);
return false;
});
return result === false;
}
// 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.
forIn(value, function(objValue, objKey) {
result = objKey;
});
return result === false || hasOwnProperty.call(value, result);
}
return result;
}
/**
* Creates a new function that, when called, invokes `func` with the `this`
* binding of `thisArg` and the arguments (value, index, object).
*
* @private
* @param {Function} func The function to bind.
* @param {Mixed} [thisArg] The `this` binding of `func`.
* @returns {Function} Returns the new bound function.
*/
function iteratorBind(func, thisArg) {
return function(value, index, object) {
return func.call(thisArg, value, index, object);
};
}
/**
* A no-operation function.
*
* @private
*/
function noop() {
// no operation performed
}
/**
* Used by `template` to replace "escape" template delimiters with tokens.
*
* @private
* @param {String} match The matched template delimiter.
* @param {String} value The delimiter value.
* @returns {String} Returns a token.
*/
function tokenizeEscape(match, value) {
if (match && reComplexDelimiter.test(value)) {
return '<e%-' + value + '%>';
}
var index = tokenized.length;
tokenized[index] = "' +\n__e(" + value + ") +\n'";
return token + index;
}
/**
* Used by `template` to replace "evaluate" template delimiters, or complex
* "escape" and "interpolate" delimiters, with tokens.
*
* @private
* @param {String} match The matched template delimiter.
* @param {String} escapeValue The complex "escape" delimiter value.
* @param {String} interpolateValue The complex "interpolate" delimiter value.
* @param {String} [evaluateValue] The "evaluate" delimiter value.
* @returns {String} Returns a token.
*/
function tokenizeEvaluate(match, escapeValue, interpolateValue, evaluateValue) {
if (evaluateValue) {
var index = tokenized.length;
tokenized[index] = "';\n" + evaluateValue + ";\n__p += '";
return token + index;
}
return escapeValue
? tokenizeEscape(null, escapeValue)
: tokenizeInterpolate(null, interpolateValue);
}
/**
* Used by `template` to replace "interpolate" template delimiters with tokens.
*
* @private
* @param {String} match The matched template delimiter.
* @param {String} value The delimiter value.
* @returns {String} Returns a token.
*/
function tokenizeInterpolate(match, value) {
if (match && reComplexDelimiter.test(value)) {
return '<e%=' + value + '%>';
}
var index = tokenized.length;
tokenized[index] = "' +\n((__t = (" + value + ")) == null ? '' : __t) +\n'";
return token + index;
}
/*--------------------------------------------------------------------------*/
/**
* Checks if `value` is an `arguments` object.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is an `arguments` object, else `false`.
* @example
*
* (function() { return _.isArguments(arguments); })(1, 2, 3);
* // => true
*
* _.isArguments([1, 2, 3]);
* // => false
*/
function isArguments(value) {
return toString.call(value) == argsClass;
}
// fallback for browsers that can't detect `arguments` objects by [[Class]]
if (noArgsClass) {
isArguments = function(value) {
return !!(value && hasOwnProperty.call(value, 'callee'));
};
}
/**
* Checks if `value` is an array.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is an array, else `false`.
* @example
*
* (function() { return _.isArray(arguments); })();
* // => false
*
* _.isArray([1, 2, 3]);
* // => true
*/
var isArray = nativeIsArray || function(value) {
return toString.call(value) == arrayClass;
};
/**
* Checks if `value` is a function.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a function, else `false`.
* @example
*
* _.isFunction(''.concat);
* // => true
*/
function isFunction(value) {
return typeof value == 'function';
}
// fallback for older versions of Chrome and Safari
if (isFunction(/x/)) {
isFunction = function(value) {
return toString.call(value) == funcClass;
};
}
/**
* A shim implementation of `Object.keys` that produces an array of the given
* object's own enumerable property names.
*
* @private
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property names.
*/
var shimKeys = createIterator({
'args': 'object',
'init': '[]',
'inLoop': 'result.push(index)'
});
/*--------------------------------------------------------------------------*/
/**
* Creates a clone of `value`. If `deep` is `true`, all nested objects will
* also be cloned otherwise they will be assigned by reference. If a value has
* a `clone` method it will be used to perform the clone. Functions, DOM nodes,
* `arguments` objects, and objects created by constructors other than `Object`
* are **not** cloned unless they have a custom `clone` method.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to clone.
* @param {Boolean} deep A flag to indicate a deep clone.
* @param {Object} [guard] Internally used to allow this method to work with
* others like `_.map` without using their callback `index` argument for `deep`.
* @param {Array} [stack=[]] Internally used to keep track of traversed objects
* to avoid circular references.
* @param {Object} thorough Internally used to indicate whether or not to perform
* a more thorough clone of non-object values.
* @returns {Mixed} Returns the cloned `value`.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 },
* { 'name': 'curly', 'age': 60 }
* ];
*
* _.clone({ 'name': 'moe' });
* // => { 'name': 'moe' }
*
* var shallow = _.clone(stooges);
* shallow[0] === stooges[0];
* // => true
*
* var deep = _.clone(stooges, true);
* shallow[0] === stooges[0];
* // => false
*/
function clone(value, deep, guard, stack, thorough) {
if (value == null) {
return value;
}
if (guard) {
deep = false;
}
// avoid slower checks on primitives
thorough || (thorough = { 'value': null });
if (thorough.value == null) {
// primitives passed from iframes use the primary document's native prototypes
thorough.value = !!(BoolProto.clone || NumberProto.clone || StringProto.clone);
}
// use custom `clone` method if available
var isObj = objectTypes[typeof value];
if ((isObj || thorough.value) && value.clone && isFunction(value.clone)) {
thorough.value = null;
return value.clone(deep);
}
// inspect [[Class]]
if (isObj) {
// don't clone `arguments` objects, functions, or non-object Objects
var className = toString.call(value);
if (!cloneableClasses[className] || (noArgsClass && isArguments(value))) {
return value;
}
var isArr = className == arrayClass;
isObj = isArr || (className == objectClass ? isPlainObject(value, true) : isObj);
}
// shallow clone
if (!isObj || !deep) {
// don't clone functions
return isObj
? (isArr ? slice.call(value) : extend({}, value))
: value;
}
var ctor = value.constructor;
switch (className) {
case boolClass:
return new ctor(value == true);
case dateClass:
return new ctor(+value);
case numberClass:
case stringClass:
return new ctor(value);
case regexpClass:
return ctor(value.source, reFlags.exec(value));
}
// check for circular references and return corresponding clone
stack || (stack = []);
var length = stack.length;
while (length--) {
if (stack[length].source == value) {
return stack[length].value;
}
}
// init cloned object
length = value.length;
var result = isArr ? ctor(length) : {};
// add current clone and original source value to the stack of traversed objects
stack.push({ 'value': result, 'source': value });
// recursively populate clone (susceptible to call stack limits)
if (isArr) {
var index = -1;
while (++index < length) {
result[index] = clone(value[index], deep, null, stack, thorough);
}
} else {
forOwn(value, function(objValue, key) {
result[key] = clone(objValue, deep, null, stack, thorough);
});
}
return result;
}
/**
* Assigns enumerable properties of the default object(s) to the `destination`
* object for all `destination` properties that resolve to `null`/`undefined`.
* Once a property is set, additional defaults of the same property will be
* ignored.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The destination object.
* @param {Object} [default1, default2, ...] The default objects.
* @returns {Object} Returns the destination object.
* @example
*
* var iceCream = { 'flavor': 'chocolate' };
* _.defaults(iceCream, { 'flavor': 'vanilla', 'sprinkles': 'rainbow' });
* // => { 'flavor': 'chocolate', 'sprinkles': 'rainbow' }
*/
var defaults = createIterator(extendIteratorOptions, {
'inLoop': 'if (result[index] == null) ' + extendIteratorOptions.inLoop
});
/**
* Creates a shallow clone of `object` excluding the specified properties.
* Property names may be specified as individual arguments or as arrays of
* property names.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The source object.
* @param {Object} [prop1, prop2, ...] The properties to drop.
* @returns {Object} Returns an object without the dropped properties.
* @example
*
* _.drop({ 'name': 'moe', 'age': 40, 'userid': 'moe1' }, 'userid');
* // => { 'name': 'moe', 'age': 40 }
*/
var drop = createIterator({
'useHas': false,
'args': 'object',
'init': '{}',
'top': 'var props = concat.apply(ArrayProto, arguments)',
'inLoop': 'if (indexOf(props, index) < 0) result[index] = value'
});
/**
* Assigns enumerable properties of the source object(s) to the `destination`
* object. Subsequent sources will overwrite propery assignments of previous
* sources.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The destination object.
* @param {Object} [source1, source2, ...] The source objects.
* @returns {Object} Returns the destination object.
* @example
*
* _.extend({ 'name': 'moe' }, { 'age': 40 });
* // => { 'name': 'moe', 'age': 40 }
*/
var extend = createIterator(extendIteratorOptions);
/**
* Iterates over `object`'s own and inherited enumerable properties, executing
* the `callback` for each property. The `callback` is bound to `thisArg` and
* invoked with 3 arguments; (value, key, object). Callbacks may exit iteration
* early by explicitly returning `false`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Object} Returns `object`.
* @example
*
* function Dog(name) {
* this.name = name;
* }
*
* Dog.prototype.bark = function() {
* alert('Woof, woof!');
* };
*
* _.forIn(new Dog('Dagny'), function(value, key) {
* alert(key);
* });
* // => alerts 'name' and 'bark' (order is not guaranteed)
*/
var forIn = createIterator(baseIteratorOptions, forEachIteratorOptions, forOwnIteratorOptions, {
'useHas': false
});
/**
* Iterates over `object`'s own enumerable properties, executing the `callback`
* for each property. The `callback` is bound to `thisArg` and invoked with 3
* arguments; (value, key, object). Callbacks may exit iteration early by
* explicitly returning `false`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Object} Returns `object`.
* @example
*
* _.forOwn({ '0': 'zero', '1': 'one', 'length': 2 }, function(num, key) {
* alert(key);
* });
* // => alerts '0', '1', and 'length' (order is not guaranteed)
*/
var forOwn = createIterator(baseIteratorOptions, forEachIteratorOptions, forOwnIteratorOptions);
/**
* Creates a sorted array of all enumerable properties, own and inherited,
* of `object` that have function values.
*
* @static
* @memberOf _
* @alias methods
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property names that have function values.
* @example
*
* _.functions(_);
* // => ['all', 'any', 'bind', 'bindAll', 'clone', 'compact', 'compose', ...]
*/
var functions = createIterator({
'useHas': false,
'args': 'object',
'init': '[]',
'inLoop': 'if (isFunction(value)) result.push(index)',
'bottom': 'result.sort()'
});
/**
* Checks if the specified object `property` exists and is a direct property,
* instead of an inherited property.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to check.
* @param {String} property The property to check for.
* @returns {Boolean} Returns `true` if key is a direct property, else `false`.
* @example
*
* _.has({ 'a': 1, 'b': 2, 'c': 3 }, 'b');
* // => true
*/
function has(object, property) {
return object ? hasOwnProperty.call(object, property) : false;
}
/**
* Checks if `value` is a boolean (`true` or `false`) value.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a boolean value, else `false`.
* @example
*
* _.isBoolean(null);
* // => false
*/
function isBoolean(value) {
return value === true || value === false || toString.call(value) == boolClass;
}
/**
* Checks if `value` is a date.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a date, else `false`.
* @example
*
* _.isDate(new Date);
* // => true
*/
function isDate(value) {
return toString.call(value) == dateClass;
}
/**
* Checks if `value` is a DOM element.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a DOM element, else `false`.
* @example
*
* _.isElement(document.body);
* // => true
*/
function isElement(value) {
return value ? value.nodeType === 1 : false;
}
/**
* Checks if `value` is empty. Arrays, strings, or `arguments` objects with a
* length of `0` and objects with no own enumerable properties are considered
* "empty".
*
* @static
* @memberOf _
* @category Objects
* @param {Array|Object|String} value The value to inspect.
* @returns {Boolean} Returns `true` if the `value` is empty, else `false`.
* @example
*
* _.isEmpty([1, 2, 3]);
* // => false
*
* _.isEmpty({});
* // => true
*
* _.isEmpty('');
* // => true
*/
var isEmpty = createIterator({
'args': 'value',
'init': 'true',
'top':
'var className = toString.call(value),\n' +
' length = value.length;\n' +
'if (arrayLikeClasses[className]' +
(noArgsClass ? ' || isArguments(value)' : '') + ' ||\n' +
' (className == objectClass && length > -1 && length === length >>> 0 &&\n' +
' isFunction(value.splice))' +
') return !length',
'inLoop': {
'object': 'return false'
}
});
/**
* Performs a deep comparison between two values to determine if they are
* equivalent to each other. If a value has an `isEqual` method it will be
* used to perform the comparison.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} a The value to compare.
* @param {Mixed} b The other value to compare.
* @param {Array} [stack=[]] Internally used to keep track of traversed objects
* to avoid circular references.
* @param {Object} thorough Internally used to indicate whether or not to perform
* a more thorough comparison of non-object values.
* @returns {Boolean} Returns `true` if the values are equvalent, else `false`.
* @example
*
* var moe = { 'name': 'moe', 'luckyNumbers': [13, 27, 34] };
* var clone = { 'name': 'moe', 'luckyNumbers': [13, 27, 34] };
*
* moe == clone;
* // => false
*
* _.isEqual(moe, clone);
* // => true
*/
function isEqual(a, b, stack, thorough) {
// a strict comparison is necessary because `null == undefined`
if (a == null || b == null) {
return a === b;
}
// avoid slower checks on non-objects
thorough || (thorough = { 'value': null });
if (thorough.value == null) {
// primitives passed from iframes use the primary document's native prototypes
thorough.value = !!(BoolProto.isEqual || NumberProto.isEqual || StringProto.isEqual);
}
if (objectTypes[typeof a] || objectTypes[typeof b] || thorough.value) {
// unwrap any LoDash wrapped values
if (a._chain) {
a = a._wrapped;
}
if (b._chain) {
b = b._wrapped;
}
// use custom `isEqual` method if available
if (a.isEqual && isFunction(a.isEqual)) {
thorough.value = null;
return a.isEqual(b);
}
if (b.isEqual && isFunction(b.isEqual)) {
thorough.value = null;
return b.isEqual(a);
}
}
// exit early for identical values
if (a === b) {
// treat `+0` vs. `-0` as not equal
return a !== 0 || (1 / a == 1 / b);
}
// compare [[Class]] names
var className = toString.call(a);
if (className != toString.call(b)) {
return false;
}
switch (className) {
case boolClass:
case dateClass:
// 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 +a == +b;
case numberClass:
// treat `NaN` vs. `NaN` as equal
return a != +a
? b != +b
// but treat `+0` vs. `-0` as not equal
: (a == 0 ? (1 / a == 1 / b) : a == +b);
case regexpClass:
case stringClass:
// coerce regexes to strings (http://es5.github.com/#x15.10.6.4)
// treat string primitives and their corresponding object instances as equal
return a == b + '';
}
// exit early, in older browsers, if `a` is array-like but not `b`
var isArr = arrayLikeClasses[className];
if (noArgsClass && !isArr && (isArr = isArguments(a)) && !isArguments(b)) {
return false;
}
// exit for functions and DOM nodes
if (!isArr && (className != objectClass || (noNodeClass && (
(typeof a.toString != 'function' && typeof (a + '') == 'string') ||
(typeof b.toString != 'function' && typeof (b + '') == 'string'))))) {
return false;
}
// assume cyclic structures are equal
// the algorithm for detecting cyclic structures is adapted from ES 5.1
// section 15.12.3, abstract operation `JO` (http://es5.github.com/#x15.12.3)
stack || (stack = []);
var length = stack.length;
while (length--) {
if (stack[length] == a) {
return true;
}
}
var index = -1,
result = true,
size = 0;
// add `a` to the stack of traversed objects
stack.push(a);
// recursively compare objects and arrays (susceptible to call stack limits)
if (isArr) {
// compare lengths to determine if a deep comparison is necessary
size = a.length;
result = size == b.length;
if (result) {
// deep compare the contents, ignoring non-numeric properties
while (size--) {
if (!(result = isEqual(a[size], b[size], stack, thorough))) {
break;
}
}
}
return result;
}
var ctorA = a.constructor,
ctorB = b.constructor;
// non `Object` object instances with different constructors are not equal
if (ctorA != ctorB && !(
isFunction(ctorA) && ctorA instanceof ctorA &&
isFunction(ctorB) && ctorB instanceof ctorB
)) {
return false;
}
// deep compare objects
for (var prop in a) {
if (hasOwnProperty.call(a, prop)) {
// count the number of properties.
size++;
// deep compare each property value.
if (!(hasOwnProperty.call(b, prop) && isEqual(a[prop], b[prop], stack, thorough))) {
return false;
}
}
}
// ensure both objects have the same number of properties
for (prop in b) {
// The JS engine in Adobe products, like InDesign, has a bug that causes
// `!size--` to throw an error so it must be wrapped in parentheses.
// https://github.com/documentcloud/underscore/issues/355
if (hasOwnProperty.call(b, prop) && !(size--)) {
// `size` will be `-1` if `b` has more properties than `a`
return false;
}
}
// handle JScript [[DontEnum]] bug
if (hasDontEnumBug) {
while (++index < 7) {
prop = shadowed[index];
if (hasOwnProperty.call(a, prop) &&
!(hasOwnProperty.call(b, prop) && isEqual(a[prop], b[prop], stack, thorough))) {
return false;
}
}
}
return true;
}
/**
* Checks if `value` is a finite number.
*
* Note: This is not the same as native `isFinite`, which will return true for
* booleans and other values. See http://es5.github.com/#x15.1.2.5.
*
* @deprecated
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a finite number, else `false`.
* @example
*
* _.isFinite(-101);
* // => true
*
* _.isFinite('10');
* // => false
*
* _.isFinite(Infinity);
* // => false
*/
function isFinite(value) {
return nativeIsFinite(value) && toString.call(value) == numberClass;
}
/**
* Checks if `value` is the language type of Object.
* (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is an object, else `false`.
* @example
*
* _.isObject({});
* // => true
*
* _.isObject(1);
* // => false
*/
function isObject(value) {
// check if the value is the ECMAScript language type of Object
// http://es5.github.com/#x8
// and avoid a V8 bug
// http://code.google.com/p/v8/issues/detail?id=2291
return value ? objectTypes[typeof value] : false;
}
/**
* Checks if `value` is `NaN`.
*
* Note: This is not the same as native `isNaN`, which will return true for
* `undefined` and other values. See http://es5.github.com/#x15.1.2.4.
*
* @deprecated
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is `NaN`, else `false`.
* @example
*
* _.isNaN(NaN);
* // => true
*
* _.isNaN(new Number(NaN));
* // => true
*
* isNaN(undefined);
* // => true
*
* _.isNaN(undefined);
* // => false
*/
function isNaN(value) {
// `NaN` as a primitive is the only value that is not equal to itself
// (perform the [[Class]] check first to avoid errors with some host objects in IE)
return toString.call(value) == numberClass && value != +value
}
/**
* Checks if `value` is `null`.
*
* @deprecated
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is `null`, else `false`.
* @example
*
* _.isNull(null);
* // => true
*
* _.isNull(undefined);
* // => false
*/
function isNull(value) {
return value === null;
}
/**
* Checks if `value` is a number.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a number, else `false`.
* @example
*
* _.isNumber(8.4 * 5;
* // => true
*/
function isNumber(value) {
return toString.call(value) == numberClass;
}
/**
* Checks if `value` is a regular expression.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a regular expression, else `false`.
* @example
*
* _.isRegExp(/moe/);
* // => true
*/
function isRegExp(value) {
return toString.call(value) == regexpClass;
}
/**
* Checks if `value` is a string.
*
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is a string, else `false`.
* @example
*
* _.isString('moe');
* // => true
*/
function isString(value) {
return toString.call(value) == stringClass;
}
/**
* Checks if `value` is `undefined`.
*
* @deprecated
* @static
* @memberOf _
* @category Objects
* @param {Mixed} value The value to check.
* @returns {Boolean} Returns `true` if the `value` is `undefined`, else `false`.
* @example
*
* _.isUndefined(void 0);
* // => true
*/
function isUndefined(value) {
return value === undefined;
}
/**
* Creates an array composed of the own enumerable property names of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property names.
* @example
*
* _.keys({ 'one': 1, 'two': 2, 'three': 3 });
* // => ['one', 'two', 'three'] (order is not guaranteed)
*/
var keys = !nativeKeys ? shimKeys : function(object) {
var type = typeof object;
// avoid iterating over the `prototype` property
if (type == 'function' && propertyIsEnumerable.call(object, 'prototype')) {
return shimKeys(object);
}
return object && objectTypes[type]
? nativeKeys(object)
: [];
};
/**
* Merges enumerable properties of the source object(s) into the `destination`
* object. Subsequent sources will overwrite propery assignments of previous
* sources.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The destination object.
* @param {Object} [source1, source2, ...] The source objects.
* @param {Object} [indicator] Internally used to indicate that the `stack`
* argument is an array of traversed objects instead of another source object.
* @param {Array} [stack=[]] Internally used to keep track of traversed objects
* to avoid circular references.
* @returns {Object} Returns the destination object.
* @example
*
* var stooges = [
* { 'name': 'moe' },
* { 'name': 'larry' }
* ];
*
* var ages = [
* { 'age': 40 },
* { 'age': 50 }
* ];
*
* _.merge(stooges, ages);
* // => [{ 'name': 'moe', 'age': 40 }, { 'name': 'larry', 'age': 50 }]
*/
var merge = createIterator(extendIteratorOptions, {
'args': 'object, source, indicator, stack',
'top':
'var destValue, found, isArr, stackLength, recursive = indicator == isPlainObject;\n' +
'if (!recursive) stack = [];\n' +
'for (var argsIndex = 1, argsLength = recursive ? 2 : arguments.length; argsIndex < argsLength; argsIndex++) {\n' +
' if (iteratee = arguments[argsIndex]) {',
'inLoop':
'if (value && ((isArr = isArray(value)) || isPlainObject(value))) {\n' +
' found = false; stackLength = stack.length;\n' +
' while (stackLength--) {\n' +
' if (found = stack[stackLength].source == value) break\n' +
' }\n' +
' if (found) {\n' +
' result[index] = stack[stackLength].value\n' +
' } else {\n' +
' destValue = (destValue = result[index]) && isArr\n' +
' ? (isArray(destValue) ? destValue : [])\n' +
' : (isPlainObject(destValue) ? destValue : {});\n' +
' stack.push({ value: destValue, source: value });\n' +
' result[index] = callee(destValue, value, isPlainObject, stack)\n' +
' }\n' +
'} else if (value != null) {\n' +
' result[index] = value\n' +
'}'
});
/**
* Creates a shallow clone of `object` composed of the specified properties.
* Property names may be specified as individual arguments or as arrays of
* property names.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The source object.
* @param {Object} [prop1, prop2, ...] The properties to pick.
* @returns {Object} Returns an object composed of the picked properties.
* @example
*
* _.pick({ 'name': 'moe', 'age': 40, 'userid': 'moe1' }, 'name', 'age');
* // => { 'name': 'moe', 'age': 40 }
*/
function pick(object) {
var result = {};
if (!object) {
return result;
}
var prop,
index = 0,
props = concat.apply(ArrayProto, arguments),
length = props.length;
// start `index` at `1` to skip `object`
while (++index < length) {
prop = props[index];
if (prop in object) {
result[prop] = object[prop];
}
}
return result;
}
/**
* Gets the size of `value` by returning `value.length` if `value` is an
* array, string, or `arguments` object. If `value` is an object, size is
* determined by returning the number of own enumerable properties it has.
*
* @deprecated
* @static
* @memberOf _
* @category Objects
* @param {Array|Object|String} value The value to inspect.
* @returns {Number} Returns `value.length` or number of own enumerable properties.
* @example
*
* _.size([1, 2]);
* // => 2
*
* _.size({ 'one': 1, 'two': 2, 'three': 3 });
* // => 3
*
* _.size('curly');
* // => 5
*/
function size(value) {
if (!value) {
return 0;
}
var className = toString.call(value),
length = value.length;
// return `value.length` for `arguments` objects, arrays, strings, and DOM
// query collections of libraries like jQuery and MooTools
// http://code.google.com/p/fbug/source/browse/branches/firebug1.9/content/firebug/chrome/reps.js?r=12614#653
// http://trac.webkit.org/browser/trunk/Source/WebCore/inspector/InjectedScriptSource.js?rev=125186#L609
if (arrayLikeClasses[className] || (noArgsClass && isArguments(value)) ||
(className == objectClass && length > -1 && length === length >>> 0 && isFunction(value.splice))) {
return length;
}
return keys(value).length;
}
/**
* Creates an array composed of the own enumerable property values of `object`.
*
* @static
* @memberOf _
* @category Objects
* @param {Object} object The object to inspect.
* @returns {Array} Returns a new array of property values.
* @example
*
* _.values({ 'one': 1, 'two': 2, 'three': 3 });
* // => [1, 2, 3]
*/
var values = createIterator({
'args': 'object',
'init': '[]',
'inLoop': 'result.push(value)'
});
/*--------------------------------------------------------------------------*/
/**
* Checks if a given `target` element is present in a `collection` using strict
* equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @alias include
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Mixed} target The value to check for.
* @returns {Boolean} Returns `true` if the `target` element is found, else `false`.
* @example
*
* _.contains([1, 2, 3], 3);
* // => true
*
* _.contains({ 'name': 'moe', 'age': 40 }, 'moe');
* // => true
*
* _.contains('curly', 'ur');
* // => true
*/
var contains = createIterator({
'args': 'collection, target',
'init': 'false',
'noCharByIndex': false,
'beforeLoop': {
'array': 'if (toString.call(iteratee) == stringClass) return collection.indexOf(target) > -1'
},
'inLoop': 'if (value === target) return true'
});
/**
* Creates an object composed of keys returned from running each element of
* `collection` through a `callback`. The corresponding value of each key is
* the number of times the key was returned by `callback`. The `callback` is
* bound to `thisArg` and invoked with 3 arguments; (value, index|key, collection).
* The `callback` argument may also be the name of a property to count by (e.g. 'length').
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|String} callback The function called per iteration or
* property name to count by.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Object} Returns the composed aggregate object.
* @example
*
* _.countBy([4.3, 6.1, 6.4], function(num) { return Math.floor(num); });
* // => { '4': 1, '6': 2 }
*
* _.countBy([4.3, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
* // => { '4': 1, '6': 2 }
*
* _.countBy(['one', 'two', 'three'], 'length');
* // => { '3': 2, '5': 1 }
*/
var countBy = createIterator(baseIteratorOptions, countByIteratorOptions);
/**
* Checks if the `callback` returns a truthy value for **all** elements of a
* `collection`. The `callback` is bound to `thisArg` and invoked with 3
* arguments; (value, index|key, collection).
*
* @static
* @memberOf _
* @alias all
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Boolean} Returns `true` if all elements pass the callback check, else `false`.
* @example
*
* _.every([true, 1, null, 'yes'], Boolean);
* // => false
*/
var every = createIterator(baseIteratorOptions, everyIteratorOptions);
/**
* Examines each element in a `collection`, returning an array of all elements
* the `callback` returns truthy for. The `callback` is bound to `thisArg` and
* invoked with 3 arguments; (value, index|key, collection).
*
* @static
* @memberOf _
* @alias select
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Array} Returns a new array of elements that passed callback check.
* @example
*
* var evens = _.filter([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => [2, 4, 6]
*/
var filter = createIterator(baseIteratorOptions, filterIteratorOptions);
/**
* Examines each element in a `collection`, returning the first one the `callback`
* returns truthy for. The function returns as soon as it finds an acceptable
* element, and does not iterate over the entire `collection`. The `callback` is
* bound to `thisArg` and invoked with 3 arguments; (value, index|key, collection).
*
* @static
* @memberOf _
* @alias detect
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Mixed} Returns the element that passed the callback check, else `undefined`.
* @example
*
* var even = _.find([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => 2
*/
var find = createIterator(baseIteratorOptions, forEachIteratorOptions, {
'init': '',
'inLoop': 'if (callback(value, index, collection)) return value'
});
/**
* Iterates over a `collection`, executing the `callback` for each element in
* the `collection`. The `callback` is bound to `thisArg` and invoked with 3
* arguments; (value, index|key, collection). Callbacks may exit iteration
* early by explicitly returning `false`.
*
* @static
* @memberOf _
* @alias each
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Array|Object} Returns `collection`.
* @example
*
* _([1, 2, 3]).forEach(alert).join(',');
* // => alerts each number and returns '1,2,3'
*
* _.forEach({ 'one': 1, 'two': 2, 'three': 3 }, alert);
* // => alerts each number (order is not guaranteed)
*/
var forEach = createIterator(baseIteratorOptions, forEachIteratorOptions);
/**
* Creates an object composed of keys returned from running each element of
* `collection` through a `callback`. The corresponding value of each key is an
* array of elements passed to `callback` that returned the key. The `callback`
* is bound to `thisArg` and invoked with 3 arguments; (value, index|key, collection).
* The `callback` argument may also be the name of a property to count by (e.g. 'length').
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|String} callback The function called per iteration or
* property name to group by.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Object} Returns the composed aggregate object.
* @example
*
* _.groupBy([4.2, 6.1, 6.4], function(num) { return Math.floor(num); });
* // => { '4': [4.2], '6': [6.1, 6.4] }
*
* _.groupBy([4.2, 6.1, 6.4], function(num) { return this.floor(num); }, Math);
* // => { '4': [4.2], '6': [6.1, 6.4] }
*
* _.groupBy(['one', 'two', 'three'], 'length');
* // => { '3': ['one', 'two'], '5': ['three'] }
*/
var groupBy = createIterator(baseIteratorOptions, countByIteratorOptions, {
'inLoop':
'prop = callback(value, index, collection);\n' +
'(hasOwnProperty.call(result, prop) ? result[prop] : result[prop] = []).push(value)'
});
/**
* Invokes the method named by `methodName` on each element in the `collection`.
* Additional arguments will be passed to each invoked method. If `methodName`
* is a function it will be invoked for, and `this` bound to, each element
* in the `collection`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|String} methodName The name of the method to invoke or
* the function invoked per iteration.
* @param {Mixed} [arg1, arg2, ...] Arguments to invoke the method with.
* @returns {Array} Returns a new array of values returned from each invoked method.
* @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 = createIterator(mapIteratorOptions, {
'args': 'collection, methodName',
'top':
'var args = slice.call(arguments, 2),\n' +
' isFunc = typeof methodName == \'function\'',
'inLoop': {
'array':
'result[index] = (isFunc ? methodName : value[methodName]).apply(value, args)',
'object':
'result' + (isKeysFast ? '[ownIndex] = ' : '.push') +
'((isFunc ? methodName : value[methodName]).apply(value, args))'
}
});
/**
* Creates a new array of values by running each element in the `collection`
* through a `callback`. The `callback` is bound to `thisArg` and invoked with
* 3 arguments; (value, index|key, collection).
*
* @static
* @memberOf _
* @alias collect
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Array} Returns a new array of elements returned by the callback.
* @example
*
* _.map([1, 2, 3], function(num) { return num * 3; });
* // => [3, 6, 9]
*
* _.map({ 'one': 1, 'two': 2, 'three': 3 }, function(num) { return num * 3; });
* // => [3, 6, 9] (order is not guaranteed)
*/
var map = createIterator(baseIteratorOptions, mapIteratorOptions);
/**
* Retrieves the value of a specified property from all elements in
* the `collection`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {String} property The property to pluck.
* @returns {Array} Returns a new array of property values.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 },
* { 'name': 'curly', 'age': 60 }
* ];
*
* _.pluck(stooges, 'name');
* // => ['moe', 'larry', 'curly']
*/
var pluck = createIterator(mapIteratorOptions, {
'args': 'collection, property',
'inLoop': {
'array': 'result[index] = value[property]',
'object': 'result' + (isKeysFast ? '[ownIndex] = ' : '.push') + '(value[property])'
}
});
/**
* Boils down a `collection` to a single value. The initial state of the
* reduction is `accumulator` and each successive step of it should be returned
* by the `callback`. The `callback` is bound to `thisArg` and invoked with 4
* arguments; for arrays they are (accumulator, value, index|key, collection).
*
* @static
* @memberOf _
* @alias foldl, inject
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [accumulator] Initial value of the accumulator.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Mixed} Returns the accumulated value.
* @example
*
* var sum = _.reduce([1, 2, 3], function(memo, num) { return memo + num; });
* // => 6
*/
var reduce = createIterator({
'args': 'collection, callback, accumulator, thisArg',
'init': 'accumulator',
'top':
'var noaccum = arguments.length < 3;\n' +
'if (thisArg) callback = iteratorBind(callback, thisArg)',
'beforeLoop': {
'array': 'if (noaccum) result = collection[++index]'
},
'inLoop': {
'array':
'result = callback(result, value, index, collection)',
'object':
'result = noaccum\n' +
' ? (noaccum = false, value)\n' +
' : callback(result, value, index, collection)'
}
});
/**
* The right-associative version of `_.reduce`.
*
* @static
* @memberOf _
* @alias foldr
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [accumulator] Initial value of the accumulator.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Mixed} Returns the accumulated value.
* @example
*
* var list = [[0, 1], [2, 3], [4, 5]];
* var flat = _.reduceRight(list, function(a, b) { return a.concat(b); }, []);
* // => [4, 5, 2, 3, 0, 1]
*/
function reduceRight(collection, callback, accumulator, thisArg) {
if (!collection) {
return accumulator;
}
var length = collection.length,
noaccum = arguments.length < 3;
if(thisArg) {
callback = iteratorBind(callback, thisArg);
}
// Opera 10.53-10.60 JITted `length >>> 0` returns the wrong value for negative numbers
if (length > -1 && length === length >>> 0) {
var iteratee = noCharByIndex && toString.call(collection) == stringClass
? collection.split('')
: collection;
if (length && noaccum) {
accumulator = iteratee[--length];
}
while (length--) {
accumulator = callback(accumulator, iteratee[length], length, collection);
}
return accumulator;
}
var prop,
props = keys(collection);
length = props.length;
if (length && noaccum) {
accumulator = collection[props[--length]];
}
while (length--) {
prop = props[length];
accumulator = callback(accumulator, collection[prop], prop, collection);
}
return accumulator;
}
/**
* The opposite of `_.filter`, this method returns the values of a
* `collection` that `callback` does **not** return truthy for.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Array} Returns a new array of elements that did **not** pass the callback check.
* @example
*
* var odds = _.reject([1, 2, 3, 4, 5, 6], function(num) { return num % 2 == 0; });
* // => [1, 3, 5]
*/
var reject = createIterator(baseIteratorOptions, filterIteratorOptions, {
'inLoop': '!' + filterIteratorOptions.inLoop
});
/**
* Checks if the `callback` returns a truthy value for **any** element of a
* `collection`. The function returns as soon as it finds passing value, and
* does not iterate over the entire `collection`. The `callback` is bound to
* `thisArg` and invoked with 3 arguments; (value, index|key, collection).
*
* @static
* @memberOf _
* @alias any
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Boolean} Returns `true` if any element passes the callback check, else `false`.
* @example
*
* _.some([null, 0, 'yes', false]);
* // => true
*/
var some = createIterator(baseIteratorOptions, everyIteratorOptions, {
'init': 'false',
'inLoop': everyIteratorOptions.inLoop.replace('!', '')
});
/**
* Creates a new array, stable sorted in ascending order by the results of
* running each element of `collection` through a `callback`. The `callback`
* is bound to `thisArg` and invoked with 3 arguments; (value, index|key, collection).
* The `callback` argument may also be the name of a property to sort by (e.g. 'length').
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Function|String} callback The function called per iteration or
* property name to sort by.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Array} Returns a new array of sorted elements.
* @example
*
* _.sortBy([1, 2, 3], function(num) { return Math.sin(num); });
* // => [3, 1, 2]
*
* _.sortBy([1, 2, 3], function(num) { return this.sin(num); }, Math);
* // => [3, 1, 2]
*
* _.sortBy(['larry', 'brendan', 'moe'], 'length');
* // => ['moe', 'larry', 'brendan']
*/
var sortBy = createIterator(baseIteratorOptions, countByIteratorOptions, mapIteratorOptions, {
'inLoop': {
'array':
'result[index] = {\n' +
' criteria: callback(value, index, collection),\n' +
' index: index,\n' +
' value: value\n' +
'}',
'object':
'result' + (isKeysFast ? '[ownIndex] = ' : '.push') + '({\n' +
' criteria: callback(value, index, collection),\n' +
' index: index,\n' +
' value: value\n' +
'})'
},
'bottom':
'result.sort(compareAscending);\n' +
'length = result.length;\n' +
'while (length--) {\n' +
' result[length] = result[length].value\n' +
'}'
});
/**
* Converts the `collection`, to an array. Useful for converting the
* `arguments` object.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to convert.
* @returns {Array} Returns the new converted array.
* @example
*
* (function() { return _.toArray(arguments).slice(1); })(1, 2, 3, 4);
* // => [2, 3, 4]
*/
function toArray(collection) {
if (!collection) {
return [];
}
if (collection.toArray && isFunction(collection.toArray)) {
return collection.toArray();
}
var length = collection.length;
if (length > -1 && length === length >>> 0) {
return (noArraySliceOnStrings ? toString.call(collection) == stringClass : typeof collection == 'string')
? collection.split('')
: slice.call(collection);
}
return values(collection);
}
/**
* Examines each element in a `collection`, returning an array of all elements
* that contain the given `properties`.
*
* @static
* @memberOf _
* @category Collections
* @param {Array|Object|String} collection The collection to iterate over.
* @param {Object} properties The object of properties/values to filter by.
* @returns {Array} Returns a new array of elements that contain the given `properties`.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 },
* { 'name': 'curly', 'age': 60 }
* ];
*
* _.where(stooges, { 'age': 40 });
* // => [{ 'name': 'moe', 'age': 40 }]
*/
var where = createIterator(filterIteratorOptions, {
'args': 'collection, properties',
'top':
'var pass, prop, propIndex, props = [];\n' +
'forIn(properties, function(value, prop) { props.push(prop) });\n' +
'var propsLength = props.length',
'inLoop':
'for (pass = true, propIndex = 0; propIndex < propsLength; propIndex++) {\n' +
' prop = props[propIndex];\n' +
' if (!(pass = value[prop] === properties[prop])) break\n' +
'}\n' +
'if (pass) result.push(value)'
});
/*--------------------------------------------------------------------------*/
/**
* Creates a new array with all falsey values of `array` removed. The values
* `false`, `null`, `0`, `""`, `undefined` and `NaN` are all falsey.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to compact.
* @returns {Array} Returns a new filtered array.
* @example
*
* _.compact([0, 1, false, 2, '', 3]);
* // => [1, 2, 3]
*/
function compact(array) {
var result = [];
if (!array) {
return result;
}
var index = -1,
length = array.length;
while (++index < length) {
if (array[index]) {
result.push(array[index]);
}
}
return result;
}
/**
* Creates a new array of `array` elements not present in the other arrays
* using strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to process.
* @param {Array} [array1, array2, ...] Arrays to check.
* @returns {Array} Returns a new array of `array` elements not present in the
* other arrays.
* @example
*
* _.difference([1, 2, 3, 4, 5], [5, 2, 10]);
* // => [1, 3, 4]
*/
function difference(array) {
var result = [];
if (!array) {
return result;
}
var index = -1,
length = array.length,
flattened = concat.apply(result, arguments),
contains = cachedContains(flattened, length);
while (++index < length) {
if (!contains(array[index])) {
result.push(array[index]);
}
}
return result;
}
/**
* Gets the first element of the `array`. Pass `n` to return the first `n`
* elements of the `array`.
*
* @static
* @memberOf _
* @alias head, take
* @category Arrays
* @param {Array} array The array to query.
* @param {Number} [n] The number of elements to return.
* @param {Object} [guard] Internally used to allow this method to work with
* others like `_.map` without using their callback `index` argument for `n`.
* @returns {Mixed} Returns the first element or an array of the first `n`
* elements of `array`.
* @example
*
* _.first([5, 4, 3, 2, 1]);
* // => 5
*/
function first(array, n, guard) {
if (array) {
return (n == null || guard) ? array[0] : slice.call(array, 0, n);
}
}
/**
* Flattens a nested array (the nesting can be to any depth). If `shallow` is
* truthy, `array` will only be flattened a single level.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to compact.
* @param {Boolean} shallow A flag to indicate only flattening a single level.
* @returns {Array} Returns a new flattened array.
* @example
*
* _.flatten([1, [2], [3, [[4]]]]);
* // => [1, 2, 3, 4];
*
* _.flatten([1, [2], [3, [[4]]]], true);
* // => [1, 2, 3, [[4]]];
*/
function flatten(array, shallow) {
var result = [];
if (!array) {
return result;
}
var value,
index = -1,
length = array.length;
while (++index < length) {
value = array[index];
if (isArray(value)) {
push.apply(result, shallow ? value : flatten(value));
} else {
result.push(value);
}
}
return result;
}
/**
* Gets the index at which the first occurrence of `value` is found using
* strict equality for comparisons, i.e. `===`. If the `array` is already
* sorted, passing `true` for `isSorted` will run a faster binary search.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to search.
* @param {Mixed} value The value to search for.
* @param {Boolean|Number} [fromIndex=0] The index to start searching from or
* `true` to perform a binary search on a sorted `array`.
* @returns {Number} Returns the index of the matched value or `-1`.
* @example
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2);
* // => 1
*
* _.indexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 4
*
* _.indexOf([1, 1, 2, 2, 3, 3], 2, true);
* // => 2
*/
function indexOf(array, value, fromIndex) {
if (!array) {
return -1;
}
var index = -1,
length = array.length;
if (fromIndex) {
if (typeof fromIndex == 'number') {
index = (fromIndex < 0 ? Math.max(0, length + fromIndex) : fromIndex) - 1;
} else {
index = sortedIndex(array, value);
return array[index] === value ? index : -1;
}
}
while (++index < length) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Gets all but the last element of `array`. Pass `n` to exclude the last `n`
* elements from the result.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @param {Number} [n] The number of elements to return.
* @param {Object} [guard] Internally used to allow this method to work with
* others like `_.map` without using their callback `index` argument for `n`.
* @returns {Array} Returns all but the last element or `n` elements of `array`.
* @example
*
* _.initial([3, 2, 1]);
* // => [3, 2]
*/
function initial(array, n, guard) {
if (!array) {
return [];
}
return slice.call(array, 0, -((n == null || guard) ? 1 : n));
}
/**
* Computes the intersection of all the passed-in arrays using strict equality
* for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} [array1, array2, ...] Arrays to process.
* @returns {Array} Returns a new array of unique elements, in order, that are
* present in **all** of the arrays.
* @example
*
* _.intersection([1, 2, 3], [101, 2, 1, 10], [2, 1]);
* // => [1, 2]
*/
function intersection(array) {
var result = [];
if (!array) {
return result;
}
var value,
index = -1,
length = array.length,
others = slice.call(arguments, 1),
cache = [];
while (++index < length) {
value = array[index];
if (indexOf(result, value) < 0 &&
every(others, function(other, index) {
return (cache[index] || (cache[index] = cachedContains(other)))(value);
})) {
result.push(value);
}
}
return result;
}
/**
* Gets the last element of the `array`. Pass `n` to return the lasy `n`
* elementsvof the `array`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to query.
* @param {Number} [n] The number of elements to return.
* @param {Object} [guard] Internally used to allow this method to work with
* others like `_.map` without using their callback `index` argument for `n`.
* @returns {Mixed} Returns the last element or an array of the last `n`
* elements of `array`.
* @example
*
* _.last([3, 2, 1]);
* // => 1
*/
function last(array, n, guard) {
if (array) {
var length = array.length;
return (n == null || guard) ? array[length - 1] : slice.call(array, -n || length);
}
}
/**
* Gets the index at which the last occurrence of `value` is found using
* strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to search.
* @param {Mixed} value The value to search for.
* @param {Number} [fromIndex=array.length-1] The index to start searching from.
* @returns {Number} Returns the index of the matched value or `-1`.
* @example
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
* // => 4
*
* _.lastIndexOf([1, 2, 3, 1, 2, 3], 2, 3);
* // => 1
*/
function lastIndexOf(array, value, fromIndex) {
if (!array) {
return -1;
}
var index = array.length;
if (fromIndex && typeof fromIndex == 'number') {
index = (fromIndex < 0 ? Math.max(0, index + fromIndex) : Math.min(fromIndex, index - 1)) + 1;
}
while (index--) {
if (array[index] === value) {
return index;
}
}
return -1;
}
/**
* Retrieves the maximum value of an `array`. If `callback` is passed,
* it will be executed for each value in the `array` to generate the
* criterion by which the value is ranked. The `callback` is bound to
* `thisArg` and invoked with 3 arguments; (value, index, array).
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to iterate over.
* @param {Function} [callback] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Mixed} Returns the maximum value.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 },
* { 'name': 'curly', 'age': 60 }
* ];
*
* _.max(stooges, function(stooge) { return stooge.age; });
* // => { 'name': 'curly', 'age': 60 };
*/
function max(array, callback, thisArg) {
var computed = -Infinity,
result = computed;
if (!array) {
return result;
}
var current,
index = -1,
length = array.length;
if (!callback) {
while (++index < length) {
if (array[index] > result) {
result = array[index];
}
}
return result;
}
if (thisArg) {
callback = iteratorBind(callback, thisArg);
}
while (++index < length) {
current = callback(array[index], index, array);
if (current > computed) {
computed = current;
result = array[index];
}
}
return result;
}
/**
* Retrieves the minimum value of an `array`. If `callback` is passed,
* it will be executed for each value in the `array` to generate the
* criterion by which the value is ranked. The `callback` is bound to `thisArg`
* and invoked with 3 arguments; (value, index, array).
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to iterate over.
* @param {Function} [callback] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Mixed} Returns the minimum value.
* @example
*
* _.min([10, 5, 100, 2, 1000]);
* // => 2
*/
function min(array, callback, thisArg) {
var computed = Infinity,
result = computed;
if (!array) {
return result;
}
var current,
index = -1,
length = array.length;
if (!callback) {
while (++index < length) {
if (array[index] < result) {
result = array[index];
}
}
return result;
}
if (thisArg) {
callback = iteratorBind(callback, thisArg);
}
while (++index < length) {
current = callback(array[index], index, array);
if (current < computed) {
computed = current;
result = array[index];
}
}
return result;
}
/**
* Creates an array of numbers (positive and/or negative) progressing from
* `start` up to but not including `stop`. This method is a port of Python's
* `range()` function. See http://docs.python.org/library/functions.html#range.
*
* @static
* @memberOf _
* @category Arrays
* @param {Number} [start=0] The start of the range.
* @param {Number} end The end of the range.
* @param {Number} [step=1] The value to increment or descrement by.
* @returns {Array} Returns a new range array.
* @example
*
* _.range(10);
* // => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
*
* _.range(1, 11);
* // => [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
*
* _.range(0, 30, 5);
* // => [0, 5, 10, 15, 20, 25]
*
* _.range(0, -10, -1);
* // => [0, -1, -2, -3, -4, -5, -6, -7, -8, -9]
*
* _.range(0);
* // => []
*/
function range(start, end, step) {
start = +start || 0;
step = +step || 1;
if (end == null) {
end = start;
start = 0;
}
// use `Array(length)` so V8 will avoid the slower "dictionary" mode
// http://www.youtube.com/watch?v=XAqIpGU8ZZk#t=16m27s
var index = -1,
length = Math.max(0, Math.ceil((end - start) / step)),
result = Array(length);
while (++index < length) {
result[index] = start;
start += step;
}
return result;
}
/**
* The opposite of `_.initial`, this method gets all but the first value of
* `array`. Pass `n` to exclude the first `n` values from the result.
*
* @static
* @memberOf _
* @alias tail
* @category Arrays
* @param {Array} array The array to query.
* @param {Number} [n] The number of elements to return.
* @param {Object} [guard] Internally used to allow this method to work with
* others like `_.map` without using their callback `index` argument for `n`.
* @returns {Array} Returns all but the first value or `n` values of `array`.
* @example
*
* _.rest([3, 2, 1]);
* // => [2, 1]
*/
function rest(array, n, guard) {
if (!array) {
return [];
}
return slice.call(array, (n == null || guard) ? 1 : n);
}
/**
* Creates a new array of shuffled `array` values, using a version of the
* Fisher-Yates shuffle. See http://en.wikipedia.org/wiki/Fisher-Yates_shuffle.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to shuffle.
* @returns {Array} Returns a new shuffled array.
* @example
*
* _.shuffle([1, 2, 3, 4, 5, 6]);
* // => [4, 1, 6, 3, 5, 2]
*/
function shuffle(array) {
if (!array) {
return [];
}
var rand,
index = -1,
length = array.length,
result = Array(length);
while (++index < length) {
rand = Math.floor(Math.random() * (index + 1));
result[index] = result[rand];
result[rand] = array[index];
}
return result;
}
/**
* Uses a binary search to determine the smallest index at which the `value`
* should be inserted into `array` in order to maintain the sort order of the
* sorted `array`. If `callback` is passed, it will be executed for `value` and
* each element in `array` to compute their sort ranking. The `callback` is
* bound to `thisArg` and invoked with 1 argument; (value).
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to iterate over.
* @param {Mixed} value The value to evaluate.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Number} Returns the index at which the value should be inserted
* into `array`.
* @example
*
* _.sortedIndex([20, 30, 40], 35);
* // => 2
*
* var dict = {
* 'wordToNumber': { 'twenty': 20, 'thirty': 30, 'thirty-five': 35, 'fourty': 40 }
* };
*
* _.sortedIndex(['twenty', 'thirty', 'fourty'], 'thirty-five', function(word) {
* return dict.wordToNumber[word];
* });
* // => 2
*
* _.sortedIndex(['twenty', 'thirty', 'fourty'], 'thirty-five', function(word) {
* return this.wordToNumber[word];
* }, dict);
* // => 2
*/
function sortedIndex(array, value, callback, thisArg) {
if (!array) {
return 0;
}
var mid,
low = 0,
high = array.length;
if (callback) {
if (thisArg) {
callback = bind(callback, thisArg);
}
value = callback(value);
while (low < high) {
mid = (low + high) >>> 1;
callback(array[mid]) < value ? low = mid + 1 : high = mid;
}
} else {
while (low < high) {
mid = (low + high) >>> 1;
array[mid] < value ? low = mid + 1 : high = mid;
}
}
return low;
}
/**
* Computes the union of the passed-in arrays using strict equality for
* comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} [array1, array2, ...] Arrays to process.
* @returns {Array} Returns a new array of unique values, in order, that are
* present in one or more of the arrays.
* @example
*
* _.union([1, 2, 3], [101, 2, 1, 10], [2, 1]);
* // => [1, 2, 3, 101, 10]
*/
function union() {
var index = -1,
result = [],
flattened = concat.apply(result, arguments),
length = flattened.length;
while (++index < length) {
if (indexOf(result, flattened[index]) < 0) {
result.push(flattened[index]);
}
}
return result;
}
/**
* Creates a duplicate-value-free version of the `array` using strict equality
* for comparisons, i.e. `===`. If the `array` is already sorted, passing `true`
* for `isSorted` will run a faster algorithm. If `callback` is passed, each
* element of `array` is passed through a callback` before uniqueness is computed.
* The `callback` is bound to `thisArg` and invoked with 3 arguments; (value, index, array).
*
* @static
* @memberOf _
* @alias unique
* @category Arrays
* @param {Array} array The array to process.
* @param {Boolean} [isSorted=false] A flag to indicate that the `array` is already sorted.
* @param {Function} [callback=identity] The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @returns {Array} Returns a duplicate-value-free array.
* @example
*
* _.uniq([1, 2, 1, 3, 1]);
* // => [1, 2, 3]
*
* _.uniq([1, 1, 2, 2, 3], true);
* // => [1, 2, 3]
*
* _.uniq([1, 2, 1.5, 3, 2.5], function(num) { return Math.floor(num); });
* // => [1, 2, 3]
*
* _.uniq([1, 2, 1.5, 3, 2.5], function(num) { return this.floor(num); }, Math);
* // => [1, 2, 3]
*/
function uniq(array, isSorted, callback, thisArg) {
var result = [];
if (!array) {
return result;
}
var computed,
index = -1,
length = array.length,
seen = [];
// juggle arguments
if (typeof isSorted == 'function') {
thisArg = callback;
callback = isSorted;
isSorted = false;
}
if (!callback) {
callback = identity;
} else if (thisArg) {
callback = iteratorBind(callback, thisArg);
}
while (++index < length) {
computed = callback(array[index], index, array);
if (isSorted
? !index || seen[seen.length - 1] !== computed
: indexOf(seen, computed) < 0
) {
seen.push(computed);
result.push(array[index]);
}
}
return result;
}
/**
* Creates a new array with all occurrences of the passed values removed using
* strict equality for comparisons, i.e. `===`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} array The array to filter.
* @param {Mixed} [value1, value2, ...] Values to remove.
* @returns {Array} Returns a new filtered array.
* @example
*
* _.without([1, 2, 1, 0, 3, 1, 4], 0, 1);
* // => [2, 3, 4]
*/
function without(array) {
var result = [];
if (!array) {
return result;
}
var index = -1,
length = array.length,
contains = cachedContains(arguments, 1, 20);
while (++index < length) {
if (!contains(array[index])) {
result.push(array[index]);
}
}
return result;
}
/**
* Groups the elements of each array at their corresponding indexes. Useful for
* separate data sources that are coordinated through matching array indexes.
* For a matrix of nested arrays, `_.zip.apply(...)` can transpose the matrix
* in a similar fashion.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} [array1, array2, ...] Arrays to process.
* @returns {Array} Returns a new array of grouped elements.
* @example
*
* _.zip(['moe', 'larry', 'curly'], [30, 40, 50], [true, false, false]);
* // => [['moe', 30, true], ['larry', 40, false], ['curly', 50, false]]
*/
function zip(array) {
if (!array) {
return [];
}
var index = -1,
length = max(pluck(arguments, 'length')),
result = Array(length);
while (++index < length) {
result[index] = pluck(arguments, index);
}
return result;
}
/**
* Creates an object composed from an array of `keys` and an array of `values`.
*
* @static
* @memberOf _
* @category Arrays
* @param {Array} keys The array of keys.
* @param {Array} [values=[]] The array of values.
* @returns {Object} Returns an object composed of the given keys and
* corresponding values.
* @example
*
* _.zipObject(['moe', 'larry', 'curly'], [30, 40, 50]);
* // => { 'moe': 30, 'larry': 40, 'curly': 50 }
*/
function zipObject(keys, values) {
if (!keys) {
return {};
}
var index = -1,
length = keys.length,
result = {};
values || (values = []);
while (++index < length) {
result[keys[index]] = values[index];
}
return result;
}
/*--------------------------------------------------------------------------*/
/**
* Creates a new function that is restricted to executing only after it is
* called `n` times.
*
* @static
* @memberOf _
* @category Functions
* @param {Number} n The number of times the function must be called before
* it is executed.
* @param {Function} func The function to restrict.
* @returns {Function} Returns the new restricted function.
* @example
*
* var renderNotes = _.after(notes.length, render);
* _.forEach(notes, function(note) {
* note.asyncSave({ 'success': renderNotes });
* });
* // `renderNotes` is run once, after all notes have saved
*/
function after(n, func) {
if (n < 1) {
return func();
}
return function() {
if (--n < 1) {
return func.apply(this, arguments);
}
};
}
/**
* Creates a new function that, when called, invokes `func` with the `this`
* binding of `thisArg` and prepends any additional `bind` arguments to those
* passed to the bound function. Lazy defined methods may be bound by passing
* the object they are bound to as `func` and the method name as `thisArg`.
*
* @static
* @memberOf _
* @category Functions
* @param {Function|Object} func The function to bind or the object the method belongs to.
* @param {Mixed} [thisArg] The `this` binding of `func` or the method name.
* @param {Mixed} [arg1, arg2, ...] Arguments to be partially applied.
* @returns {Function} Returns the new bound function.
* @example
*
* // basic bind
* var func = function(greeting) {
* return greeting + ' ' + this.name;
* };
*
* func = _.bind(func, { 'name': 'moe' }, 'hi');
* func();
* // => 'hi moe'
*
* // lazy bind
* var object = {
* 'name': 'moe',
* 'greet': function(greeting) {
* return greeting + ' ' + this.name;
* }
* };
*
* var func = _.bind(object, 'greet', 'hi');
* func();
* // => 'hi moe'
*
* object.greet = function(greeting) {
* return greeting + ', ' + this.name + '!';
* };
*
* func();
* // => 'hi, moe!'
*/
function bind(func, thisArg) {
var methodName,
isFunc = isFunction(func);
// juggle arguments
if (!isFunc) {
methodName = thisArg;
thisArg = func;
}
// use `Function#bind` if it exists and is fast
// (in V8 `Function#bind` is slower except when partially applied)
else if (isBindFast || (nativeBind && arguments.length > 2)) {
return nativeBind.call.apply(nativeBind, arguments);
}
var partialArgs = slice.call(arguments, 2);
function bound() {
// `Function#bind` spec
// http://es5.github.com/#x15.3.4.5
var args = arguments,
thisBinding = thisArg;
if (!isFunc) {
func = thisArg[methodName];
}
if (partialArgs.length) {
args = args.length
? partialArgs.concat(slice.call(args))
: partialArgs;
}
if (this instanceof bound) {
// get `func` instance if `bound` is invoked in a `new` expression
noop.prototype = func.prototype;
thisBinding = new noop;
// mimic the constructor's `return` behavior
// http://es5.github.com/#x13.2.2
var result = func.apply(thisBinding, args);
return result && objectTypes[typeof result]
? result
: thisBinding
}
return func.apply(thisBinding, args);
}
return bound;
}
/**
* Binds methods on `object` to `object`, overwriting the existing method.
* If no method names are provided, all the function properties of `object`
* will be bound.
*
* @static
* @memberOf _
* @category Functions
* @param {Object} object The object to bind and assign the bound methods to.
* @param {String} [methodName1, methodName2, ...] Method names on the object to bind.
* @returns {Object} Returns `object`.
* @example
*
* var buttonView = {
* 'label': 'lodash',
* 'onClick': function() { alert('clicked: ' + this.label); }
* };
*
* _.bindAll(buttonView);
* jQuery('#lodash_button').on('click', buttonView.onClick);
* // => When the button is clicked, `this.label` will have the correct value
*/
var bindAll = createIterator({
'useHas': false,
'useStrict': false,
'args': 'object',
'init': 'object',
'top':
'var funcs = arguments,\n' +
' length = funcs.length;\n' +
'if (length > 1) {\n' +
' for (var index = 1; index < length; index++) {\n' +
' result[funcs[index]] = bind(result[funcs[index]], result)\n' +
' }\n' +
' return result\n' +
'}',
'inLoop':
'if (isFunction(result[index])) {\n' +
' result[index] = bind(result[index], result)\n' +
'}'
});
/**
* Creates a new function that is the composition of the passed functions,
* where each function consumes the return value of the function that follows.
* In math terms, composing the functions `f()`, `g()`, and `h()` produces `f(g(h()))`.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} [func1, func2, ...] Functions to compose.
* @returns {Function} Returns the new composed function.
* @example
*
* var greet = function(name) { return 'hi: ' + name; };
* var exclaim = function(statement) { return statement + '!'; };
* var welcome = _.compose(exclaim, greet);
* welcome('moe');
* // => 'hi: moe!'
*/
function compose() {
var funcs = arguments;
return function() {
var args = arguments,
length = funcs.length;
while (length--) {
args = [funcs[length].apply(this, args)];
}
return args[0];
};
}
/**
* Creates a new function that will delay the execution of `func` until after
* `wait` milliseconds have elapsed since the last time it was invoked. Pass
* `true` for `immediate` to cause debounce to invoke `func` on the leading,
* instead of the trailing, edge of the `wait` timeout. Subsequent calls to
* the debounced function will return the result of the last `func` call.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to debounce.
* @param {Number} wait The number of milliseconds to delay.
* @param {Boolean} immediate A flag to indicate execution is on the leading
* edge of the timeout.
* @returns {Function} Returns the new debounced function.
* @example
*
* var lazyLayout = _.debounce(calculateLayout, 300);
* jQuery(window).on('resize', lazyLayout);
*/
function debounce(func, wait, immediate) {
var args,
result,
thisArg,
timeoutId;
function delayed() {
timeoutId = null;
if (!immediate) {
func.apply(thisArg, args);
}
}
return function() {
var isImmediate = immediate && !timeoutId;
args = arguments;
thisArg = this;
clearTimeout(timeoutId);
timeoutId = setTimeout(delayed, wait);
if (isImmediate) {
result = func.apply(thisArg, args);
}
return result;
};
}
/**
* Executes the `func` function after `wait` milliseconds. Additional arguments
* will be passed to `func` when it is invoked.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to delay.
* @param {Number} wait The number of milliseconds to delay execution.
* @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
* @returns {Number} Returns the `setTimeout` timeout id.
* @example
*
* var log = _.bind(console.log, console);
* _.delay(log, 1000, 'logged later');
* // => 'logged later' (Appears after one second.)
*/
function delay(func, wait) {
var args = slice.call(arguments, 2);
return setTimeout(function() { return func.apply(undefined, args); }, wait);
}
/**
* Defers executing the `func` function until the current call stack has cleared.
* Additional arguments will be passed to `func` when it is invoked.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to defer.
* @param {Mixed} [arg1, arg2, ...] Arguments to invoke the function with.
* @returns {Number} Returns the `setTimeout` timeout id.
* @example
*
* _.defer(function() { alert('deferred'); });
* // returns from the function before `alert` is called
*/
function defer(func) {
var args = slice.call(arguments, 1);
return setTimeout(function() { return func.apply(undefined, args); }, 1);
}
/**
* Creates a new function that memoizes the result of `func`. If `resolver` is
* passed, it will be used to determine the cache key for storing the result
* based on the arguments passed to the memoized function. By default, the first
* argument passed to the memoized function is used as the cache key.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to have its output memoized.
* @param {Function} [resolver] A function used to resolve the cache key.
* @returns {Function} Returns the new memoizing function.
* @example
*
* var fibonacci = _.memoize(function(n) {
* return n < 2 ? n : fibonacci(n - 1) + fibonacci(n - 2);
* });
*/
function memoize(func, resolver) {
var cache = {};
return function() {
var prop = resolver ? resolver.apply(this, arguments) : arguments[0];
return hasOwnProperty.call(cache, prop)
? cache[prop]
: (cache[prop] = func.apply(this, arguments));
};
}
/**
* Creates a new function that is restricted to one execution. Repeat calls to
* the function will return the value of the first call.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to restrict.
* @returns {Function} Returns the new restricted function.
* @example
*
* var initialize = _.once(createApplication);
* initialize();
* initialize();
* // Application is only created once.
*/
function once(func) {
var result,
ran = false;
return function() {
if (ran) {
return result;
}
ran = true;
result = func.apply(this, arguments);
// clear the `func` variable so the function may be garbage collected
func = null;
return result;
};
}
/**
* Creates a new function that, when called, invokes `func` with any additional
* `partial` arguments prepended to those passed to the new function. This method
* is similar `bind`, except it does **not** alter the `this` binding.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to partially apply arguments to.
* @param {Mixed} [arg1, arg2, ...] Arguments to be partially applied.
* @returns {Function} Returns the new partially applied function.
* @example
*
* var greet = function(greeting, name) { return greeting + ': ' + name; };
* var hi = _.partial(greet, 'hi');
* hi('moe');
* // => 'hi: moe'
*/
function partial(func) {
var args = slice.call(arguments, 1),
argsLength = args.length;
return function() {
var result,
others = arguments;
if (others.length) {
args.length = argsLength;
push.apply(args, others);
}
result = args.length == 1 ? func.call(this, args[0]) : func.apply(this, args);
args.length = argsLength;
return result;
};
}
/**
* Creates a new function that, when executed, will only call the `func`
* function at most once per every `wait` milliseconds. If the throttled
* function is invoked more than once during the `wait` timeout, `func` will
* also be called on the trailing edge of the timeout. Subsequent calls to the
* throttled function will return the result of the last `func` call.
*
* @static
* @memberOf _
* @category Functions
* @param {Function} func The function to throttle.
* @param {Number} wait The number of milliseconds to throttle executions to.
* @returns {Function} Returns the new throttled function.
* @example
*
* var throttled = _.throttle(updatePosition, 100);
* jQuery(window).on('scroll', throttled);
*/
function throttle(func, wait) {
var args,
result,
thisArg,
timeoutId,
lastCalled = 0;
function trailingCall() {
lastCalled = new Date;
timeoutId = null;
func.apply(thisArg, args);
}
return function() {
var now = new Date,
remain = wait - (now - lastCalled);
args = arguments;
thisArg = this;
if (remain <= 0) {
lastCalled = now;
result = func.apply(thisArg, args);
}
else if (!timeoutId) {
timeoutId = setTimeout(trailingCall, remain);
}
return result;
};
}
/**
* Creates a new function that passes `value` to the `wrapper` function as its
* first argument. Additional arguments passed to the new function are appended
* to those passed to the `wrapper` function.
*
* @static
* @memberOf _
* @category Functions
* @param {Mixed} value The value to wrap.
* @param {Function} wrapper The wrapper function.
* @returns {Function} Returns the new function.
* @example
*
* var hello = function(name) { return 'hello: ' + name; };
* hello = _.wrap(hello, function(func) {
* return 'before, ' + func('moe') + ', after';
* });
* hello();
* // => 'before, hello: moe, after'
*/
function wrap(value, wrapper) {
return function() {
var args = [value];
if (arguments.length) {
push.apply(args, arguments);
}
return wrapper.apply(this, args);
};
}
/*--------------------------------------------------------------------------*/
/**
* Escapes a string for inclusion in HTML, replacing `&`, `<`, `"`, and `'`
* characters.
*
* @static
* @memberOf _
* @category Utilities
* @param {String} string The string to escape.
* @returns {String} Returns the escaped string.
* @example
*
* _.escape('Moe, Larry & Curly');
* // => "Moe, Larry & Curly"
*/
function escape(string) {
return string == null ? '' : (string + '').replace(reUnescapedHtml, escapeHtmlChar);
}
/**
* This function returns the first argument passed to it.
*
* Note: It is used throughout Lo-Dash as a default callback.
*
* @static
* @memberOf _
* @category Utilities
* @param {Mixed} value Any value.
* @returns {Mixed} Returns `value`.
* @example
*
* var moe = { 'name': 'moe' };
* moe === _.identity(moe);
* // => true
*/
function identity(value) {
return value;
}
/**
* Adds functions properties of `object` to the `lodash` function and chainable
* wrapper.
*
* @static
* @memberOf _
* @category Utilities
* @param {Object} object The object of function properties to add to `lodash`.
* @example
*
* _.mixin({
* 'capitalize': function(string) {
* return string.charAt(0).toUpperCase() + string.slice(1).toLowerCase();
* }
* });
*
* _.capitalize('larry');
* // => 'Larry'
*
* _('curly').capitalize();
* // => 'Curly'
*/
function mixin(object) {
forEach(functions(object), function(methodName) {
var func = lodash[methodName] = object[methodName];
LoDash.prototype[methodName] = function() {
var args = [this._wrapped];
if (arguments.length) {
push.apply(args, arguments);
}
var result = func.apply(lodash, args);
if (this._chain) {
result = new LoDash(result);
result._chain = true;
}
return result;
};
});
}
/**
* Reverts the '_' variable to its previous value and returns a reference to
* the `lodash` function.
*
* @static
* @memberOf _
* @category Utilities
* @returns {Function} Returns the `lodash` function.
* @example
*
* var lodash = _.noConflict();
*/
function noConflict() {
window._ = oldDash;
return this;
}
/**
* Resolves the value of `property` on `object`. If `property` is a function
* it will be invoked and its result returned, else the property value is
* returned. If `object` is falsey, then `null` is returned.
*
* @deprecated
* @static
* @memberOf _
* @category Utilities
* @param {Object} object The object to inspect.
* @param {String} property The property to get the result of.
* @returns {Mixed} Returns the resolved value.
* @example
*
* var object = {
* 'cheese': 'crumpets',
* 'stuff': function() {
* return 'nonsense';
* }
* };
*
* _.result(object, 'cheese');
* // => 'crumpets'
*
* _.result(object, 'stuff');
* // => 'nonsense'
*/
function result(object, property) {
// based on Backbone's private `getValue` function
// https://github.com/documentcloud/backbone/blob/0.9.2/backbone.js#L1419-1424
if (!object) {
return null;
}
var value = object[property];
return isFunction(value) ? object[property]() : value;
}
/**
* A micro-templating method that handles arbitrary delimiters, preserves
* whitespace, and correctly escapes quotes within interpolated code.
*
* Note: In the development build `_.template` utilizes sourceURLs for easier
* debugging. See http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
*
* Note: Lo-Dash may be used in Chrome extensions by either creating a `lodash csp`
* build and avoiding `_.template` use, or loading Lo-Dash in a sandboxed page.
* See http://developer.chrome.com/trunk/extensions/sandboxingEval.html
*
* @static
* @memberOf _
* @category Utilities
* @param {String} text The template text.
* @param {Obect} data The data object used to populate the text.
* @param {Object} options The options object.
* @returns {Function|String} Returns a compiled function when no `data` object
* is given, else it returns the interpolated text.
* @example
*
* // using a compiled template
* var compiled = _.template('hello: <%= name %>');
* compiled({ 'name': 'moe' });
* // => 'hello: moe'
*
* var list = '<% _.forEach(people, function(name) { %> <li><%= name %></li> <% }); %>';
* _.template(list, { 'people': ['moe', 'larry', 'curly'] });
* // => '<li>moe</li><li>larry</li><li>curly</li>'
*
* // using the "escape" delimiter to escape HTML in data property values
* _.template('<b><%- value %></b>', { 'value': '<script>' });
* // => '<b><script></b>'
*
* // using the internal `print` function in "evaluate" delimiters
* _.template('<% print("Hello " + epithet); %>', { 'epithet': 'stooge' });
* // => 'Hello stooge.'
*
* // using custom template delimiter settings
* _.templateSettings = {
* 'interpolate': /\{\{(.+?)\}\}/g
* };
*
* _.template('Hello {{ name }}!', { 'name': 'Mustache' });
* // => 'Hello Mustache!'
*
* // using the `variable` option to ensure a with-statement isn't used in the compiled template
* var compiled = _.template('hello: <%= data.name %>', null, { 'variable': 'data' });
* compiled.source;
* // => function(data) {
* var __t, __p = '', __e = _.escape;
* __p += 'hello: ' + ((__t = ( data.name )) == null ? '' : __t);
* return __p;
* }
*
* // using the `source` property to inline compiled templates for meaningful
* // line numbers in error messages and a stack trace
* fs.writeFileSync(path.join(cwd, 'jst.js'), '\
* var JST = {\
* "main": ' + _.template(mainText).source + '\
* };\
* ');
*/
function template(text, data, options) {
// based on John Resig's `tmpl` implementation
// http://ejohn.org/blog/javascript-micro-templating/
// and Laura Doktorova's doT.js
// https://github.com/olado/doT
options || (options = {});
text += '';
var isEvaluating,
result,
escapeDelimiter = options.escape,
evaluateDelimiter = options.evaluate,
interpolateDelimiter = options.interpolate,
settings = lodash.templateSettings,
variable = options.variable || settings.variable,
hasVariable = variable;
// use default settings if no options object is provided
if (escapeDelimiter == null) {
escapeDelimiter = settings.escape;
}
if (evaluateDelimiter == null) {
// use `false` as the fallback value, instead of leaving it `undefined`,
// so the initial assignment of `reEvaluateDelimiter` will still occur
evaluateDelimiter = settings.evaluate || false;
}
if (interpolateDelimiter == null) {
interpolateDelimiter = settings.interpolate;
}
// tokenize delimiters to avoid escaping them
if (escapeDelimiter) {
text = text.replace(escapeDelimiter, tokenizeEscape);
}
if (interpolateDelimiter) {
text = text.replace(interpolateDelimiter, tokenizeInterpolate);
}
if (evaluateDelimiter != lastEvaluateDelimiter) {
// generate `reEvaluateDelimiter` to match `_.templateSettings.evaluate`
// and internal `<e%- %>`, `<e%= %>` delimiters
lastEvaluateDelimiter = evaluateDelimiter;
reEvaluateDelimiter = RegExp(
'<e%-([\\s\\S]+?)%>|<e%=([\\s\\S]+?)%>' +
(evaluateDelimiter ? '|' + evaluateDelimiter.source : '')
, 'g');
}
isEvaluating = tokenized.length;
text = text.replace(reEvaluateDelimiter, tokenizeEvaluate);
isEvaluating = isEvaluating != tokenized.length;
// escape characters that cannot be included in string literals and
// detokenize delimiter code snippets
text = "__p += '" + text
.replace(reUnescapedString, escapeStringChar)
.replace(reToken, detokenize) + "';\n";
// clear stored code snippets
tokenized.length = 0;
// if `variable` is not specified and the template contains "evaluate"
// delimiters, wrap a with-statement around the generated code to add the
// data object to the top of the scope chain
if (!hasVariable) {
variable = lastVariable || 'obj';
if (isEvaluating) {
text = 'with (' + variable + ') {\n' + text + '\n}\n';
}
else {
if (variable != lastVariable) {
// generate `reDoubleVariable` to match references like `obj.obj` inside
// transformed "escape" and "interpolate" delimiters
lastVariable = variable;
reDoubleVariable = RegExp('(\\(\\s*)' + variable + '\\.' + variable + '\\b', 'g');
}
// avoid a with-statement by prepending data object references to property names
text = text
.replace(reInsertVariable, '$&' + variable + '.')
.replace(reDoubleVariable, '$1__d');
}
}
// cleanup code by stripping empty strings
text = ( isEvaluating ? text.replace(reEmptyStringLeading, '') : text)
.replace(reEmptyStringMiddle, '$1')
.replace(reEmptyStringTrailing, '$1;');
// frame code as the function body
text = 'function(' + variable + ') {\n' +
(hasVariable ? '' : variable + ' || (' + variable + ' = {});\n') +
'var __t, __p = \'\', __e = _.escape' +
(isEvaluating
? ', __j = Array.prototype.join;\n' +
'function print() { __p += __j.call(arguments, \'\') }\n'
: (hasVariable ? '' : ', __d = ' + variable + '.' + variable + ' || ' + variable) + ';\n'
) +
text +
'return __p\n}';
// add a sourceURL for easier debugging
// http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/#toc-sourceurl
if (useSourceURL) {
text += '\n//@ sourceURL=/lodash/template/source[' + (templateCounter++) + ']';
}
try {
result = Function('_', 'return ' + text)(lodash);
} catch(e) {
// defer syntax errors until the compiled template is executed to allow
// examining the `source` property beforehand and for consistency,
// because other template related errors occur at execution
result = function() { throw e; };
}
if (data) {
return result(data);
}
// provide the compiled function's source via its `toString` method, in
// supported environments, or the `source` property as a convenience for
// inlining compiled templates during the build process
result.source = text;
return result;
}
/**
* Executes the `callback` function `n` times. The `callback` is bound to
* `thisArg` and invoked with 1 argument; (index).
*
* @static
* @memberOf _
* @category Utilities
* @param {Number} n The number of times to execute the callback.
* @param {Function} callback The function called per iteration.
* @param {Mixed} [thisArg] The `this` binding for the callback.
* @example
*
* _.times(3, function() { genie.grantWish(); });
* // => calls `genie.grantWish()` 3 times
*
* _.times(3, function() { this.grantWish(); }, genie);
* // => also calls `genie.grantWish()` 3 times
*/
function times(n, callback, thisArg) {
var index = -1;
if (thisArg) {
while (++index < n) {
callback.call(thisArg, index);
}
} else {
while (++index < n) {
callback(index);
}
}
}
/**
* Generates a unique id. If `prefix` is passed, the id will be appended to it.
*
* @static
* @memberOf _
* @category Utilities
* @param {String} [prefix] The value to prefix the id with.
* @returns {Number|String} Returns a numeric id if no prefix is passed, else
* a string id may be returned.
* @example
*
* _.uniqueId('contact_');
* // => 'contact_104'
*/
function uniqueId(prefix) {
var id = idCounter++;
return prefix ? prefix + id : id;
}
/*--------------------------------------------------------------------------*/
/**
* Wraps the value in a `lodash` wrapper object.
*
* @static
* @memberOf _
* @category Chaining
* @param {Mixed} value The value to wrap.
* @returns {Object} Returns the wrapper object.
* @example
*
* var stooges = [
* { 'name': 'moe', 'age': 40 },
* { 'name': 'larry', 'age': 50 },
* { 'name': 'curly', 'age': 60 }
* ];
*
* var youngest = _.chain(stooges)
* .sortBy(function(stooge) { return stooge.age; })
* .map(function(stooge) { return stooge.name + ' is ' + stooge.age; })
* .first()
* .value();
* // => 'moe is 40'
*/
function chain(value) {
value = new LoDash(value);
value._chain = true;
return value;
}
/**
* Invokes `interceptor` with the `value` as the first argument, and then
* returns `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 Chaining
* @param {Mixed} value The value to pass to `interceptor`.
* @param {Function} interceptor The function to invoke.
* @returns {Mixed} Returns `value`.
* @example
*
* _.chain([1,2,3,200])
* .filter(function(num) { return num % 2 == 0; })
* .tap(alert)
* .map(function(num) { return num * num })
* .value();
* // => // [2, 200] (alerted)
* // => [4, 40000]
*/
function tap(value, interceptor) {
interceptor(value);
return value;
}
/**
* Enables method chaining on the wrapper object.
*
* @name chain
* @deprecated
* @memberOf _
* @category Chaining
* @returns {Mixed} Returns the wrapper object.
* @example
*
* _([1, 2, 3]).value();
* // => [1, 2, 3]
*/
function wrapperChain() {
this._chain = true;
return this;
}
/**
* Extracts the wrapped value.
*
* @name value
* @memberOf _
* @category Chaining
* @returns {Mixed} Returns the wrapped value.
* @example
*
* _([1, 2, 3]).value();
* // => [1, 2, 3]
*/
function wrapperValue() {
return this._wrapped;
}
/*--------------------------------------------------------------------------*/
/**
* The semantic version number.
*
* @static
* @memberOf _
* @type String
*/
lodash.VERSION = '0.5.2';
// assign static methods
lodash.after = after;
lodash.bind = bind;
lodash.bindAll = bindAll;
lodash.chain = chain;
lodash.clone = clone;
lodash.compact = compact;
lodash.compose = compose;
lodash.contains = contains;
lodash.countBy = countBy;
lodash.debounce = debounce;
lodash.defaults = defaults;
lodash.defer = defer;
lodash.delay = delay;
lodash.difference = difference;
lodash.drop = drop;
lodash.escape = escape;
lodash.every = every;
lodash.extend = extend;
lodash.filter = filter;
lodash.find = find;
lodash.first = first;
lodash.flatten = flatten;
lodash.forEach = forEach;
lodash.forIn = forIn;
lodash.forOwn = forOwn;
lodash.functions = functions;
lodash.groupBy = groupBy;
lodash.has = has;
lodash.identity = identity;
lodash.indexOf = indexOf;
lodash.initial = initial;
lodash.intersection = intersection;
lodash.invoke = invoke;
lodash.isArguments = isArguments;
lodash.isArray = isArray;
lodash.isBoolean = isBoolean;
lodash.isDate = isDate;
lodash.isElement = isElement;
lodash.isEmpty = isEmpty;
lodash.isEqual = isEqual;
lodash.isFinite = isFinite;
lodash.isFunction = isFunction;
lodash.isNaN = isNaN;
lodash.isNull = isNull;
lodash.isNumber = isNumber;
lodash.isObject = isObject;
lodash.isRegExp = isRegExp;
lodash.isString = isString;
lodash.isUndefined = isUndefined;
lodash.keys = keys;
lodash.last = last;
lodash.lastIndexOf = lastIndexOf;
lodash.map = map;
lodash.max = max;
lodash.memoize = memoize;
lodash.merge = merge;
lodash.min = min;
lodash.mixin = mixin;
lodash.noConflict = noConflict;
lodash.once = once;
lodash.partial = partial;
lodash.pick = pick;
lodash.pluck = pluck;
lodash.range = range;
lodash.reduce = reduce;
lodash.reduceRight = reduceRight;
lodash.reject = reject;
lodash.rest = rest;
lodash.result = result;
lodash.shuffle = shuffle;
lodash.size = size;
lodash.some = some;
lodash.sortBy = sortBy;
lodash.sortedIndex = sortedIndex;
lodash.tap = tap;
lodash.template = template;
lodash.throttle = throttle;
lodash.times = times;
lodash.toArray = toArray;
lodash.union = union;
lodash.uniq = uniq;
lodash.uniqueId = uniqueId;
lodash.values = values;
lodash.where = where;
lodash.without = without;
lodash.wrap = wrap;
lodash.zip = zip;
lodash.zipObject = zipObject;
// assign aliases
lodash.all = every;
lodash.any = some;
lodash.collect = map;
lodash.detect = find;
lodash.each = forEach;
lodash.foldl = reduce;
lodash.foldr = reduceRight;
lodash.head = first;
lodash.include = contains;
lodash.inject = reduce;
lodash.methods = functions;
lodash.select = filter;
lodash.tail = rest;
lodash.take = first;
lodash.unique = uniq;
// add pseudo private properties used and removed during the build process
lodash._iteratorTemplate = iteratorTemplate;
lodash._shimKeys = shimKeys;
/*--------------------------------------------------------------------------*/
// assign private `LoDash` constructor's prototype
LoDash.prototype = lodash.prototype;
// add all static functions to `LoDash.prototype`
mixin(lodash);
// add `LoDash.prototype.chain` after calling `mixin()` to avoid overwriting
// it with the wrapped `lodash.chain`
LoDash.prototype.chain = wrapperChain;
LoDash.prototype.value = wrapperValue;
// add all mutator Array functions to the wrapper.
forEach(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(methodName) {
var func = ArrayProto[methodName];
LoDash.prototype[methodName] = function() {
var value = this._wrapped;
func.apply(value, arguments);
// Firefox < 10, IE compatibility mode, and IE < 9 have buggy Array
// `shift()` and `splice()` functions that fail to remove the last element,
// `value[0]`, of array-like objects even though the `length` property is
// set to `0`. The `shift()` method is buggy in IE 8 compatibility mode,
// while `splice()` is buggy regardless of mode in IE < 9 and buggy in
// compatibility mode in IE 9.
if (value.length === 0) {
delete value[0];
}
if (this._chain) {
value = new LoDash(value);
value._chain = true;
}
return value;
};
});
// add all accessor Array functions to the wrapper.
forEach(['concat', 'join', 'slice'], function(methodName) {
var func = ArrayProto[methodName];
LoDash.prototype[methodName] = function() {
var value = this._wrapped,
result = func.apply(value, arguments);
if (this._chain) {
result = new LoDash(result);
result._chain = true;
}
return result;
};
});
/*--------------------------------------------------------------------------*/
// expose Lo-Dash
// some AMD build optimizers, like r.js, check for specific condition patterns like the following:
if (typeof define == 'function' && typeof define.amd == 'object' && define.amd) {
// Expose Lo-Dash to the global object even when an AMD loader is present in
// case Lo-Dash was injected by a third-party script and not intended to be
// loaded as a module. The global assignment can be reverted in the Lo-Dash
// module via its `noConflict()` method.
window._ = lodash;
// define as an anonymous module so, through path mapping, it can be
// referenced as the "underscore" module
define(function() {
return lodash;
});
}
// check for `exports` after `define` in case a build optimizer adds an `exports` object
else if (freeExports) {
// in Node.js or RingoJS v0.8.0+
if (typeof module == 'object' && module && module.exports == freeExports) {
(module.exports = lodash)._ = lodash;
}
// in Narwhal or RingoJS v0.7.0-
else {
freeExports._ = lodash;
}
}
else {
// in a browser or Rhino
window._ = lodash;
}
}(this));