/ajax/libs//0.2.0/lodash.js

/*!
 * Lo-Dash v0.2.0 <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';

  /** Detect free variable `exports` */
  var freeExports = typeof exports == 'object' && exports &&
    (typeof global == 'object' && global && global == global.global && (window = global), exports);

  /**
   * Used to detect the JavaScript engine's argument length limit.
   *
   * The initial value of `argsLimit` is low enough not to cause uncatchable
   * errors in Java and avoid locking up older browsers like Safari 3.
   *
   * Some engines have a limit on the number of arguments functions can accept
   * before clipping the argument length or throwing an error.
   * https://bugs.webkit.org/show_bug.cgi?id=80797
   *
   * For example Firefox's limits have been observed to be at least:
   *   Firefox 2    - 35,535
   *   Firefox 3.6  - 16,777,215
   *   Firefox 4-7  - 523,264
   *   Firefox >= 8 - Throws error
   */
  var argsLimit = 5e4;

  try {
    (function() {
      argsLimit = arguments.length;
    }).apply(null, Array(argsLimit));
  } catch(e) { }

  /** Used to escape characters in templates */
  var escapes = {
    '\\': '\\',
    "'": "'",
    '\n': 'n',
    '\r': 'r',
    '\t': 't',
    '\u2028': 'u2028',
    '\u2029': 'u2029'
  };

  /**
   * Detect the JScript [[DontEnum]] bug:
   * In IE < 9 an objects own properties, shadowing non-enumerable ones, are
   * made non-enumerable as well.
   */
  var hasDontEnumBug = !{ 'valueOf': 0 }.propertyIsEnumerable('valueOf');

  /** Used to generate unique IDs */
  var idCounter = 0;

  /** 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
  };

  /** Used to restore the original `_` reference in `noConflict` */
  var oldDash = window._;

  /** Used to match the "escape" template delimiters */
  var reEscapeDelimiter = /<%-([\s\S]+?)%>/g;

  /** Used to match the "evaluate" template delimiters */
  var reEvaluateDelimiter = /<%([\s\S]+?)%>/g;

  /** Used to match the "interpolate" template delimiters */
  var reInterpolateDelimiter = /<%=([\s\S]+?)%>/g;

  /** Used to detect if a method is native */
  var reNative = RegExp('^' + ({}.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 template text */
  var reUnescaped = /['\n\r\t\u2028\u2029\\]/g;

  /** Used to fix the JScript [[DontEnum]] bug */
  var shadowed = [
    'constructor', 'hasOwnProperty', 'isPrototypeOf', 'propertyIsEnumerable',
    'toLocaleString', 'toString', 'valueOf'
  ];

  /** Used to replace template delimiters */
  var token = '__token__';

  /** Used to store tokenized template text snippets */
  var tokenized = [];

  /** Object#toString result shortcuts */
  var arrayClass = '[object Array]',
      boolClass = '[object Boolean]',
      dateClass = '[object Date]',
      funcClass = '[object Function]',
      numberClass = '[object Number]',
      regexpClass = '[object RegExp]',
      stringClass = '[object String]';

  /** Native prototype shortcuts */
  var ArrayProto = Array.prototype,
      ObjectProto = Object.prototype;

  /** Native method shortcuts */
  var concat = ArrayProto.concat,
      hasOwnProperty = ObjectProto.hasOwnProperty,
      push = ArrayProto.push,
      slice = ArrayProto.slice,
      toString = ObjectProto.toString;

  /* Used if `Function#bind` exists and is inferred to be fast (i.e. all but V8) */
  var nativeBind = reNative.test(nativeBind = slice.bind) &&
    /\n|Opera/.test(nativeBind + toString.call(window.opera)) && nativeBind;

  /* Native method shortcuts for methods with the same name as other `lodash` methods */
  var nativeIsArray = reNative.test(nativeIsArray = Array.isArray) && nativeIsArray,
      nativeIsFinite = window.isFinite,
      nativeKeys = reNative.test(nativeKeys = Object.keys) && nativeKeys;

  /** Timer shortcuts */
  var clearTimeout = window.clearTimeout,
      setTimeout = window.setTimeout;

  /*--------------------------------------------------------------------------*/

  /**
   * 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(
    // assign the `result` variable an initial value
    'var index, 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 = <%= firstArg %>.length; index = -1;' +
    '  <% if (objectBranch) { %>\nif (length === +length) {<% } %>\n' +
    '  <%= arrayBranch.beforeLoop %>;\n' +
    '  while (<%= arrayBranch.loopExp %>) {\n' +
    '    <%= arrayBranch.inLoop %>;\n' +
    '  }' +
    '  <% if (objectBranch) { %>\n}\n<% }' +
    '}' +

    // the following branch is for iterating an object's own/inherited properties
    'if (objectBranch) {' +
    '  if (arrayBranch) { %>else {\n<% }' +
    '  if (!hasDontEnumBug) { %>  var skipProto = typeof <%= iteratedObject %> == \'function\';\n<% } %>' +
    '  <%= objectBranch.beforeLoop %>;\n' +
    '  for (<%= objectBranch.loopExp %>) {' +
    '  \n<%' +
    '  if (hasDontEnumBug) {' +
    '    if (useHas) { %>    if (<%= hasExp %>) {\n  <% } %>' +
    '    <%= objectBranch.inLoop %>;<%' +
    '    if (useHas) { %>\n    }<% }' +
    '  }' +
    '  else {' +
    '  %>' +

    // 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.
    '    if (!(skipProto && index == \'prototype\')<% if (useHas) { %> && <%= hasExp %><% } %>) {\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' +
    '  var ctor = <%= iteratedObject %>.constructor;\n' +
    '  <% for (var k = 0; k < 7; k++) { %>\n' +
    '  index = \'<%= shadowed[k] %>\';\n' +
    '  if (<%' +
    '      if (shadowed[k] == \'constructor\') {' +
    '        %>!(ctor && ctor.prototype === <%= iteratedObject %>) && <%' +
    '      } %><%= hasExp %>) {\n' +
    '    <%= objectBranch.inLoop %>;\n' +
    '  }<%' +
    '     }' +
    '   }' +
    '   if (arrayBranch) { %>\n}<% }' +
    '} %>\n' +

    // add code to the bottom of the iteration function
    '<%= bottom %>;\n' +
    // finally, return the `result`
    'return result'

    , null, {
    'evaluate': reEvaluateDelimiter,
    'interpolate': reInterpolateDelimiter
  });

  /**
   * Reusable iterator options shared by
   * `every`, `filter`, `find`, `forEach`,`groupBy`, `map`, `reject`, and `some`.
   */
  var baseIteratorOptions = {
    'args': 'collection, callback, thisArg',
    'init': 'collection',
    'top':
      'if (!callback) {\n' +
      '  callback = identity\n' +
      '}\n' +
      'else if (thisArg) {\n' +
      '  callback = bind(callback, thisArg)\n' +
      '}',
    'inLoop': 'callback(collection[index], index, collection)'
  };

  /** Reusable iterator options for `every` and `some` */
  var everyIteratorOptions = {
    'init': 'true',
    'inLoop': 'if (!callback(collection[index], index, collection)) return !result'
  };

  /** Reusable iterator options for `defaults` and `extend` */
  var extendIteratorOptions = {
    'args': 'object',
    'init': 'object',
    'top':
      'for (var source, sourceIndex = 1, length = arguments.length; sourceIndex < length; sourceIndex++) {\n' +
      '  source = arguments[sourceIndex];\n' +
      (hasDontEnumBug ? '  if (source) {' : ''),
    'loopExp': 'index in source',
    'useHas': false,
    'inLoop': 'object[index] = source[index]',
    'bottom': (hasDontEnumBug ? '  }\n' : '') + '}'
  };

  /** Reusable iterator options for `filter`  and `reject` */
  var filterIteratorOptions = {
    'init': '[]',
    'inLoop': 'callback(collection[index], index, collection) && result.push(collection[index])'
  };

  /** Reusable iterator options for `map`, `pluck`, and `values` */
  var mapIteratorOptions = {
    'init': '',
    'exit': 'if (!collection) return []',
    'beforeLoop': {
      'array':  'result = Array(length)',
      'object': 'result = []'
    },
    'inLoop': {
      'array':  'result[index] = callback(collection[index], index, collection)',
      'object': 'result.push(callback(collection[index], index, collection))'
    }
  };

  /*--------------------------------------------------------------------------*/

  /**
   * 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;
  }

  /*--------------------------------------------------------------------------*/

  /**
   * Checks if a `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 a `value` is empty. Arrays or strings with a length of `0` and
   * objects with no enumerable own properties are considered "empty".
   *
   * @static
   * @memberOf _
   * @category Objects
   * @param {Mixed} value The value to check.
   * @returns {Boolean} Returns `true` if the `value` is empty, else `false`.
   * @example
   *
   * _.isEmpty([1, 2, 3]);
   * // => false
   *
   * _.isEmpty({});
   * // => true
   */
  var isEmpty = createIterator({
    'args': 'value',
    'init': 'true',
    'top':
      'var className = toString.call(value);\n' +
      'if (className == arrayClass || className == stringClass) return !value.length',
    'inLoop': {
      'object': 'return false'
    }
  });

  /*--------------------------------------------------------------------------*/

  /**
   * 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.
   *
   *  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.
   *
   *  loopExp - A string or object containing an "array" or "object" property
   *   of code to execute as the array or object loop expression.
   *
   *  useHas - A boolean to specify whether or not to use `hasOwnProperty` checks
   *   in the object loop.
   *
   *  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': { 'loopExp': '++index < length' },
      'objectBranch': {}
    };

    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|loopExp|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,
        arrayBranch = data.arrayBranch,
        objectBranch = data.objectBranch,
        firstArg = /^[^,]+/.exec(args)[0],
        loopExp = objectBranch.loopExp,
        iteratedObject = /\S+$/.exec(loopExp || firstArg)[0];

    data.firstArg = firstArg;
    data.hasDontEnumBug = hasDontEnumBug;
    data.hasExp = 'hasOwnProperty.call(' + iteratedObject + ', index)';
    data.iteratedObject = iteratedObject;
    data.shadowed = shadowed;
    data.useHas = data.useHas !== false;

    if (!data.exit) {
      data.exit = 'if (' + firstArg + ' == null) return result';
    }
    if (firstArg == 'object' || !arrayBranch.inLoop) {
      data.arrayBranch = null;
    }
    if (!loopExp) {
      objectBranch.loopExp = 'index in ' + iteratedObject;
    }
    // create the function factory
    var factory = Function(
        'arrayClass, bind, concat, funcClass, hasOwnProperty, identity, indexOf, ' +
        'isArray, isEmpty, objectTypes, slice, stringClass, toString, undefined',
      '"use strict"; return function(' + args + ') {\n' + iteratorTemplate(data) + '\n}'
    );
    // return the compiled function
    return factory(
      arrayClass, bind, concat, funcClass, hasOwnProperty, identity, indexOf,
      isArray, isEmpty, objectTypes, slice, stringClass, toString
    );
  }

  /**
   * 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 escapeChar(match) {
    return '\\' + escapes[match];
  }

  /**
   * 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) {
    var index = tokenized.length;
    tokenized[index] = "'+\n((__t = (" + value + ")) == null ? '' : _.escape(__t)) +\n'";
    return token + index;
  }

  /**
   * 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) {
    var index = tokenized.length;
    tokenized[index] = "'+\n((__t = (" + value + ")) == null ? '' : __t) +\n'";
    return token + index;
  }

  /**
   * Used by `template()` to replace "evaluate" template delimiters with tokens.
   *
   * @private
   * @param {String} match The matched template delimiter.
   * @param {String} value The delimiter value.
   * @returns {String} Returns a token.
   */
  function tokenizeEvaluate(match, value) {
    var index = tokenized.length;
    tokenized[index] = "';\n" + value + ";\n__p += '";
    return token + index;
  }

  /*--------------------------------------------------------------------------*/

  /**
   * Checks if a given `target` value is present in a `collection` using strict
   * equality for comparisons, i.e. `===`.
   *
   * @static
   * @memberOf _
   * @alias include
   * @category Collections
   * @param {Array|Object} collection The collection to iterate over.
   * @param {Mixed} target The value to check for.
   * @returns {Boolean} Returns `true` if `target` value is found, else `false`.
   * @example
   *
   * _.contains([1, 2, 3], 3);
   * // => true
   */
  var contains = createIterator({
    'args': 'collection, target',
    'init': 'false',
    'inLoop': 'if (collection[index] === target) return true'
  });

  /**
   * Checks if the `callback` returns a truthy value for **all** elements of a
   * `collection`. The `callback` is invoked with 3 arguments; for arrays they
   * are (value, index, array) and for objects they are (value, key, object).
   *
   * @static
   * @memberOf _
   * @alias all
   * @category Collections
   * @param {Array|Object} collection The collection to iterate over.
   * @param {Function} callback The function called per iteration.
   * @param {Mixed} [thisArg] The `this` binding for the callback.
   * @returns {Boolean} Returns `true` if all values pass the callback check, else `false`.
   * @example
   *
   * _.every([true, 1, null, 'yes'], Boolean);
   * // => false
   */
  var every = createIterator(baseIteratorOptions, everyIteratorOptions);

  /**
   * Examines each value in a `collection`, returning an array of all values the
   * `callback` returns truthy for. The `callback` is invoked with 3 arguments;
   * for arrays they are (value, index, array) and for objects they are
   * (value, key, object).
   *
   * @static
   * @memberOf _
   * @alias select
   * @category Collections
   * @param {Array|Object} 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} Returns a new array of values 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 value in a `collection`, returning the first one the `callback`
   * returns truthy for. The function returns as soon as it finds an acceptable
   * value, and does not iterate over the entire `collection`. The `callback` is
   * invoked with 3 arguments; for arrays they are (value, index, array) and for
   * objects they are (value, key, object).
   *
   * @static
   * @memberOf _
   * @alias detect
   * @category Collections
   * @param {Array|Object} 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 value 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, {
    'inLoop': 'if (callback(collection[index], index, collection)) return collection[index]'
  });

  /**
   * Iterates over a `collection`, executing the `callback` for each value in the
   * `collection`. The `callback` is bound to the `thisArg` value, if one is passed.
   * The `callback` is invoked with 3 arguments; for arrays they are
   * (value, index, array) and for objects they are (value, key, object).
   *
   * @static
   * @memberOf _
   * @alias each
   * @category Collections
   * @param {Array|Object} 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 the `collection`.
   * @example
   *
   * _.forEach({ 'one': 1, 'two': 2, 'three': 3}, function(num) { alert(num); });
   * // => alerts each number in turn
   *
   * _([1, 2, 3]).forEach(function(num) { alert(num); }).join(',');
   * // => alerts each number in turn and returns '1,2,3'
   */
  var forEach = createIterator(baseIteratorOptions, {
    'top': 'if (thisArg) callback = bind(callback, thisArg)'
  });

  /**
   * Splits a `collection` into sets, grouped by the result of running each value
   * through `callback`. The `callback` is invoked with 3 arguments; for arrays
   * they are (value, index, array) and for objects they are (value, key, object).
   * The `callback` argument may also be the name of a property to group by.
   *
   * @static
   * @memberOf _
   * @category Collections
   * @param {Array|Object} 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 an object of grouped values.
   * @example
   *
   * _.groupBy([1.3, 2.1, 2.4], function(num) { return Math.floor(num); });
   * // => { '1': [1.3], '2': [2.1, 2.4] }
   *
   * _.groupBy([1.3, 2.1, 2.4], function(num) { return this.floor(num); }, Math);
   * // => { '1': [1.3], '2': [2.1, 2.4] }
   *
   * _.groupBy(['one', 'two', 'three'], 'length');
   * // => { '3': ['one', 'two'], '5': ['three'] }
   */
  var groupBy = createIterator(baseIteratorOptions, {
    'init': '{}',
    'top':
      'var prop, isFunc = toString.call(callback) == funcClass;\n' +
      'if (isFunc && thisArg) callback = bind(callback, thisArg)',
    'inLoop':
      'prop = isFunc\n' +
      '  ? callback(collection[index], index, collection)\n' +
      '  : collection[index][callback];\n' +
      '(result[prop] || (result[prop] = [])).push(collection[index])'
  });

  /**
   * Produces a new array of values by mapping each value in the `collection`
   * through a transformation `callback`. The `callback` is bound to the `thisArg`
   * value, if one is passed. The `callback` is invoked with 3 arguments; for
   * arrays they are (value, index, array) and for objects they are (value, key, object).
   *
   * @static
   * @memberOf _
   * @alias collect
   * @category Collections
   * @param {Array|Object} 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} Returns a new array of values 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]
   */
  var map = createIterator(baseIteratorOptions, mapIteratorOptions);

  /**
   * Retrieves the value of a specified property from all values in a `collection`.
   *
   * @static
   * @memberOf _
   * @category Collections
   * @param {Array|Object} 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] = collection[index][property]',
      'object': 'result.push(collection[index][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 the `thisArg` value, if one is
   * passed. The `callback` is invoked with 4 arguments; for arrays they are
   * (accumulator, value, index, array) and for objects they are
   * (accumulator, value, key, object).
   *
   * @static
   * @memberOf _
   * @alias foldl, inject
   * @category Collections
   * @param {Array|Object} 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 = bind(callback, thisArg)',
    'beforeLoop': {
      'array': 'if (noaccum) result = collection[++index]'
    },
    'inLoop': {
      'array':
        'result = callback(result, collection[index], index, collection)',
      'object':
        'result = noaccum\n' +
        '  ? (noaccum = false, collection[index])\n' +
        '  : callback(result, collection[index], index, collection)'
    }
  });

  /**
   * The right-associative version of `_.reduce`. The `callback` is bound to the
   * `thisArg` value, if one is passed. The `callback` is invoked with 4 arguments;
   * for arrays they are (accumulator, value, index, array) and for objects they
   * are (accumulator, value, key, object).
   *
   * @static
   * @memberOf _
   * @alias foldr
   * @category Collections
   * @param {Array|Object} 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 = bind(callback, thisArg);
    }
    if (length === +length) {
      if (length && noaccum) {
        accumulator = collection[--length];
      }
      while (length--) {
        accumulator = callback(accumulator, collection[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. The `callback` is invoked
   * with 3 arguments; for arrays they are (value, index, array) and for objects
   * they are (value, key, object).
   *
   * @static
   * @memberOf _
   * @category Collections
   * @param {Array|Object} 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} Returns a new array of values 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
  });

  /**
   * Gets the number of values in the `collection` or the `length` of a string value.
   *
   * @static
   * @memberOf _
   * @category Collections
   * @param {Array|Object} collection The collection inspect.
   * @returns {Number} Returns the number of values in the collection.
   * @example
   *
   * _.size([1, 2]);
   * // => 2
   *
   * _.size({ 'one': 1, 'two': 2, 'three': 3 });
   * // => 3
   *
   * _.size('curly');
   * // => 5
   */
  function size(collection) {
    var className = toString.call(collection);
    return className == arrayClass || className == stringClass
      ? collection.length
      : keys(collection).length;
  }

  /**
   * Produces a new sorted array, ranked in ascending order by the results of
   * running each value of a `collection` through `callback`. The `callback` is
   * invoked with 3 arguments; for arrays they are (value, index, array) and for
   * objects they are (value, key, object). The `callback` argument may also be
   * the name of a property to sort by (e.g. 'length').
   *
   * @static
   * @memberOf _
   * @category Collections
   * @param {Array|Object} 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 values.
   * @example
   *
   * _.sortBy([1, 2, 3, 4, 5, 6], function(num) { return Math.sin(num); });
   * // => [5, 4, 6, 3, 1, 2]
   *
   * _.sortBy([1, 2, 3, 4, 5, 6], function(num) { return this.sin(num); }, Math);
   * // => [5, 4, 6, 3, 1, 2]
   */
  function sortBy(collection, callback, thisArg) {
    if (toString.call(callback) != funcClass) {
      var prop = callback;
      callback = function(collection) { return collection[prop]; };
    } else if (thisArg) {
      callback = bind(callback, thisArg);
    }
    return pluck(map(collection, function(value, index) {
      return {
        'criteria': callback(value, index, collection),
        'value': value
      };
    }).sort(function(left, right) {
      var a = left.criteria,
          b = right.criteria;

      if (a === undefined) {
        return 1;
      }
      if (b === undefined) {
        return -1;
      }
      return a < b ? -1 : a > b ? 1 : 0;
    }), 'value');
  }

  /**
   * 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 invoked
   * with 3 arguments; for arrays they are (value, index, array) and for objects
   * they are (value, key, object).
   *
   * @static
   * @memberOf _
   * @alias any
   * @category Collections
   * @param {Array|Object} collection The collection to iterate over.
   * @param {Function} callback The function called per iteration.
   * @param {Mixed} [thisArg] The `this` binding for the callback.
   * @returns {Boolean} Returns `true` if any value passes the callback check, else `false`.
   * @example
   *
   * _.some([null, 0, 'yes', false]);
   * // => true
   */
  var some = createIterator(baseIteratorOptions, everyIteratorOptions, {
    'init': 'false',
    'inLoop': everyIteratorOptions.inLoop.replace('!', '')
  });

  /**
   * Converts the `collection`, into an array. Useful for converting the
   * `arguments` object.
   *
   * @static
   * @memberOf _
   * @category Collections
   * @param {Array|Object} 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 (toString.call(collection.toArray) == funcClass) {
      return collection.toArray();
    }
    var length = collection.length;
    if (length === +length) {
      return slice.call(collection);
    }
    return values(collection);
  }

  /**
   * Produces an array of enumerable own property values of the `collection`.
   *
   * @static
   * @memberOf _
   * @alias methods
   * @category Collections
   * @param {Array|Object} collection The collection 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(mapIteratorOptions, {
    'args': 'collection',
    'inLoop': {
      'array':  'result[index] = collection[index]',
      'object': 'result.push(collection[index])'
    }
  });

  /*--------------------------------------------------------------------------*/

  /**
   * Produces 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 index = -1,
        length = array.length,
        result = [];

    while (++index < length) {
      if (array[index]) {
        result.push(array[index]);
      }
    }
    return result;
  }

  /**
   * Produces a new array of `array` values 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` values not present in the
   *  other arrays.
   * @example
   *
   * _.difference([1, 2, 3, 4, 5], [5, 2, 10]);
   * // => [1, 3, 4]
   */
  function difference(array) {
    var index = -1,
        length = array.length,
        result = [],
        flattened = concat.apply(result, slice.call(arguments, 1));

    while (++index < length) {
      if (indexOf(flattened, array[index]) < 0) {
        result.push(array[index]);
      }
    }
    return result;
  }

  /**
   * Gets the first value of the `array`. Pass `n` to return the first `n` values
   * 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 value or an array of the first `n` values
   *  of the `array`.
   * @example
   *
   * _.first([5, 4, 3, 2, 1]);
   * // => 5
   */
  function first(array, n, guard) {
    return (n == undefined || 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) {
    if (shallow) {
      return concat.apply(ArrayProto, array);
    }
    var value,
        index = -1,
        length = array.length,
        result = [];

    while (++index < length) {
      value = array[index];
      if (isArray(value)) {
        push.apply(result, 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} [isSorted=false] A flag to indicate that the `array` is already sorted.
   * @returns {Number} Returns the index of the matched value or `-1`.
   * @example
   *
   * _.indexOf([1, 2, 3], 2);
   * // => 1
   */
  function indexOf(array, value, isSorted) {
    var index, length;
    if (!array) {
      return -1;
    }
    if (isSorted) {
      index = sortedIndex(array, value);
      return array[index] === value ? index : -1;
    }
    for (index = 0, length = array.length; index < length; index++) {
      if (array[index] === value) {
        return index;
      }
    }
    return -1;
  }

  /**
   * Gets all but the last value of the `array`. Pass `n` to exclude the last `n`
   * values 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 value or `n` values of the `array`.
   * @example
   *
   * _.initial([5, 4, 3, 2, 1]);
   * // => [5, 4, 3, 2]
   */
  function initial(array, n, guard) {
    return slice.call(array, 0, -((n == undefined || guard) ? 1 : n));
  }

  /**
   * Computes the intersection of all the passed-in arrays.
   *
   * @static
   * @memberOf _
   * @alias intersect
   * @category Arrays
   * @param {Array} [array1, array2, ...] Arrays to process.
   * @returns {Array} Returns a new array of unique values, 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 value,
        index = -1,
        length = array.length,
        others = slice.call(arguments, 1),
        result = [];

    while (++index < length) {
      value = array[index];
      if (indexOf(result, value) < 0 &&
          every(others, function(other) { return indexOf(other, value) > -1; })) {
        result.push(value);
      }
    }
    return result;
  }

  /**
   * Calls the method named by `methodName` for each value of the `collection`.
   * Additional arguments will be passed to each invoked method.
   *
   * @static
   * @memberOf _
   * @category Arrays
   * @param {Array} array The array to iterate over.
   * @param {String} methodName The name of the method to invoke.
   * @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]]
   */
  function invoke(array, methodName) {
    var args = slice.call(arguments, 2),
        index = -1,
        length = array.length,
        isFunc = toString.call(methodName) == funcClass,
        result = [];

    while (++index < length) {
      result[index] = (isFunc ? methodName : array[index][methodName]).apply(array[index], args);
    }
    return result;
  }

  /**
   * Gets the last value of the `array`. Pass `n` to return the lasy `n` values
   * of 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 {Array} Returns all but the last value or `n` values of the `array`.
   * @example
   *
   * _.last([5, 4, 3, 2, 1]);
   * // => 1
   */
  function last(array, n, guard) {
    var length = array.length;
    return (n == undefined || 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.
   * @returns {Number} Returns the index of the matched value or `-1`.
   * @example
   *
   * _.lastIndexOf([1, 2, 3, 1, 2, 3], 2);
   * // => 4
   */
  function lastIndexOf(array, value) {
    if (!array) {
      return -1;
    }
    var index = array.length;
    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 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 current,
        computed = -Infinity,
        index = -1,
        length = array.length,
        result = computed;

    if (!callback) {
      // fast path for arrays of numbers
      if (array[0] === +array[0] && length <= argsLimit) {
        // some JavaScript engines have a limit on the number of arguments functions
        // can accept before clipping the argument length or throwing an error
        try {
          return Math.max.apply(Math, array);
        } catch(e) { }
      }
      if (!array.length) {
        return result;
      }
    } else if (thisArg) {
      callback = bind(callback, thisArg);
    }
    while (++index < length) {
      current = callback ? callback(array[index], index, array) : array[index];
      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 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 current,
        computed = Infinity,
        index = -1,
        length = array.length,
        result = computed;

    if (!callback) {
      if (array[0] === +array[0] && length <= argsLimit) {
        try {
          return Math.min.apply(Math, array);
        } catch(e) { }
      }
      if (!array.length) {
        return result;
      }
    } else if (thisArg) {
      callback = bind(callback, thisArg);
    }
    while (++index < length) {
      current = callback ? callback(array[index], index, array) : array[index];
      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) {
    step || (step = 1);
    if (arguments.length < 2) {
      end = start || 0;
      start = 0;
    }

    var index = -1,
        length = Math.max(Math.ceil((end - start) / step), 0),
        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
   * the `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 the `array`.
   * @example
   *
   * _.rest([5, 4, 3, 2, 1]);
   * // => [4, 3, 2, 1]
   */
  function rest(array, n, guard) {
    return slice.call(array, (n == undefined || guard) ? 1 : n);
  }

  /**
   * Produces 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) {
    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 the `collection` in order to maintain the sort order
   * of the `collection`. If `callback` is passed, it will be executed for each
   * value in the `collection` to compute their sort ranking. The `callback` is
   * 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] The function called per iteration.
   * @returns {Number} Returns the index at which the value should be inserted
   *  into the collection.
   * @example
   *
   * _.sortedIndex([10, 20, 30, 40, 50], 35);
   * // => 3
   */
  function sortedIndex(array, value, callback) {
    var mid,
        low = 0,
        high = array.length;

    if (callback) {
      value = callback(value);
    }
    while (low < high) {
      mid = (low + high) >> 1;
      if ((callback ? callback(array[mid]) : array[mid]) < value) {
        low = mid + 1;
      } else {
        high = mid;
      }
    }
    return low;
  }

  /**
   * Computes the union of the passed-in arrays.
   *
   * @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;
  }

  /**
   * Produces a duplicate-value-free version of the `array` using strict equality
   * for comparisons, i.e. `===`