// Underscore.js
// (c) 2009 Jeremy Ashkenas, DocumentCloud Inc.
// Underscore is freely distributable under the terms of the MIT license.
// Portions of Underscore are inspired by or borrowed from Prototype.js,
// Oliver Steele's Functional, and John Resig's Micro-Templating.
// For all details and documentation:
// http://documentcloud.github.com/underscore/
 
(function() {
 
  /*------------------------- Baseline setup ---------------------------------*/
 
  // Establish the root object, "window" in the browser, or "global" on the server.
  var root = this;
 
  // Save the previous value of the "_" variable.
  var previousUnderscore = root._;
 
  // If Underscore is called as a function, it returns a wrapped object that
  // can be used OO-style. This wrapper holds altered versions of all the
  // underscore functions. Wrapped objects may be chained.
  var wrapper = function(obj) { this._wrapped = obj; };
 
  // Establish the object that gets thrown to break out of a loop iteration.
  var breaker = typeof StopIteration !== 'undefined' ? StopIteration : '__break__';
 
  // Create a safe reference to the Underscore object for reference below.
  var _ = root._ = function(obj) { return new wrapper(obj); };
 
  // Export the Underscore object for CommonJS.
  if (typeof exports !== 'undefined') exports._ = _;
 
  // Current version.
  _.VERSION = '0.4.3';
 
  /*------------------------ Collection Functions: ---------------------------*/
 
  // The cornerstone, an each implementation.
  // Handles objects implementing forEach, arrays, and raw objects.
  _.each = function(obj, iterator, context) {
    var index = 0;
    try {
      if (obj.forEach) {
        obj.forEach(iterator, context);
      } else if (obj.length) {
        for (var i=0, l = obj.length; i<l; i++) iterator.call(context, obj[i], i, obj);
      } else {
        for (var key in obj) if (Object.prototype.hasOwnProperty.call(obj, key)) {
          iterator.call(context, obj[key], key, obj);
        }
      }
    } catch(e) {
      if (e != breaker) throw e;
    }
    return obj;
  };
 
  // Return the results of applying the iterator to each element. Use JavaScript
  // 1.6's version of map, if possible.
  _.map = function(obj, iterator, context) {
    if (obj && obj.map) return obj.map(iterator, context);
    var results = [];
    _.each(obj, function(value, index, list) {
      results.push(iterator.call(context, value, index, list));
    });
    return results;
  };
 
  // Reduce builds up a single result from a list of values. Also known as
  // inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
  _.reduce = function(obj, memo, iterator, context) {
    if (obj && obj.reduce) return obj.reduce(_.bind(iterator, context), memo);
    _.each(obj, function(value, index, list) {
      memo = iterator.call(context, memo, value, index, list);
    });
    return memo;
  };
 
  // The right-associative version of reduce, also known as foldr. Uses
  // JavaScript 1.8's version of reduceRight, if available.
  _.reduceRight = function(obj, memo, iterator, context) {
    if (obj && obj.reduceRight) return obj.reduceRight(_.bind(iterator, context), memo);
    var reversed = _.clone(_.toArray(obj)).reverse();
    _.each(reversed, function(value, index) {
      memo = iterator.call(context, memo, value, index, obj);
    });
    return memo;
  };
 
  // Return the first value which passes a truth test.
  _.detect = function(obj, iterator, context) {
    var result;
    _.each(obj, function(value, index, list) {
      if (iterator.call(context, value, index, list)) {
        result = value;
        _.breakLoop();
      }
    });
    return result;
  };
 
  // Return all the elements that pass a truth test. Use JavaScript 1.6's
  // filter(), if it exists.
  _.select = function(obj, iterator, context) {
    if (obj.filter) return obj.filter(iterator, context);
    var results = [];
    _.each(obj, function(value, index, list) {
      iterator.call(context, value, index, list) && results.push(value);
    });
    return results;
  };
 
  // Return all the elements for which a truth test fails.
  _.reject = function(obj, iterator, context) {
    var results = [];
    _.each(obj, function(value, index, list) {
      !iterator.call(context, value, index, list) && results.push(value);
    });
    return results;
  };
 
  // Determine whether all of the elements match a truth test. Delegate to
  // JavaScript 1.6's every(), if it is present.
  _.all = function(obj, iterator, context) {
    iterator = iterator || _.identity;
    if (obj.every) return obj.every(iterator, context);
    var result = true;
    _.each(obj, function(value, index, list) {
      if (!(result = result && iterator.call(context, value, index, list))) _.breakLoop();
    });
    return result;
  };
 
  // Determine if at least one element in the object matches a truth test. Use
  // JavaScript 1.6's some(), if it exists.
  _.any = function(obj, iterator, context) {
    iterator = iterator || _.identity;
    if (obj.some) return obj.some(iterator, context);
    var result = false;
    _.each(obj, function(value, index, list) {
      if (result = iterator.call(context, value, index, list)) _.breakLoop();
    });
    return result;
  };
 
  // Determine if a given value is included in the array or object,
  // based on '==='.
  _.include = function(obj, target) {
    if (_.isArray(obj)) return _.indexOf(obj, target) != -1;
    var found = false;
    _.each(obj, function(value) {
      if (found = value === target) _.breakLoop();
    });
    return found;
  };
 
  // Invoke a method with arguments on every item in a collection.
  _.invoke = function(obj, method) {
    var args = _.toArray(arguments).slice(2);
    return _.map(obj, function(value) {
      return (method ? value[method] : value).apply(value, args);
    });
  };
 
  // Convenience version of a common use case of map: fetching a property.
  _.pluck = function(obj, key) {
    return _.map(obj, function(value){ return value[key]; });
  };
 
  // Return the maximum item or (item-based computation).
  _.max = function(obj, iterator, context) {
    if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj);
    var result = {computed : -Infinity};
    _.each(obj, function(value, index, list) {
      var computed = iterator ? iterator.call(context, value, index, list) : value;
      computed >= result.computed && (result = {value : value, computed : computed});
    });
    return result.value;
  };
 
  // Return the minimum element (or element-based computation).
  _.min = function(obj, iterator, context) {
    if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj);
    var result = {computed : Infinity};
    _.each(obj, function(value, index, list) {
      var computed = iterator ? iterator.call(context, value, index, list) : value;
      computed < result.computed && (result = {value : value, computed : computed});
    });
    return result.value;
  };
 
  // Sort the object's values by a criteria produced by an iterator.
  _.sortBy = function(obj, iterator, context) {
    return _.pluck(_.map(obj, function(value, index, list) {
      return {
        value : value,
        criteria : iterator.call(context, value, index, list)
      };
    }).sort(function(left, right) {
      var a = left.criteria, b = right.criteria;
      return a < b ? -1 : a > b ? 1 : 0;
    }), 'value');
  };
 
  // Use a comparator function to figure out at what index an object should
  // be inserted so as to maintain order. Uses binary search.
  _.sortedIndex = function(array, obj, iterator) {
    iterator = iterator || _.identity;
    var low = 0, high = array.length;
    while (low < high) {
      var mid = (low + high) >> 1;
      iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid;
    }
    return low;
  };
 
  // Convert anything iterable into a real, live array.
  _.toArray = function(iterable) {
    if (!iterable) return [];
    if (_.isArray(iterable)) return iterable;
    return _.map(iterable, function(val){ return val; });
  };
 
  // Return the number of elements in an object.
  _.size = function(obj) {
    return _.toArray(obj).length;
  };
 
  /*-------------------------- Array Functions: ------------------------------*/
 
  // Get the first element of an array.
  _.first = function(array) {
    return array[0];
  };
 
  // Get the last element of an array.
  _.last = function(array) {
    return array[array.length - 1];
  };
 
  // Trim out all falsy values from an array.
  _.compact = function(array) {
    return _.select(array, function(value){ return !!value; });
  };
 
  // Return a completely flattened version of an array.
  _.flatten = function(array) {
    return _.reduce(array, [], function(memo, value) {
      if (_.isArray(value)) return memo.concat(_.flatten(value));
      memo.push(value);
      return memo;
    });
  };
 
  // Return a version of the array that does not contain the specified value(s).
  _.without = function(array) {
    var values = array.slice.call(arguments, 0);
    return _.select(array, function(value){ return !_.include(values, value); });
  };
 
  // Produce a duplicate-free version of the array. If the array has already
  // been sorted, you have the option of using a faster algorithm.
  _.uniq = function(array, isSorted) {
    return _.reduce(array, [], function(memo, el, i) {
      if (0 == i || (isSorted ? _.last(memo) != el : !_.include(memo, el))) memo.push(el);
      return memo;
    });
  };
 
  // Produce an array that contains every item shared between all the
  // passed-in arrays.
  _.intersect = function(array) {
    var rest = _.toArray(arguments).slice(1);
    return _.select(_.uniq(array), function(item) {
      return _.all(rest, function(other) {
        return _.indexOf(other, item) >= 0;
      });
    });
  };
 
  // Zip together multiple lists into a single array -- elements that share
  // an index go together.
  _.zip = function() {
    var args = _.toArray(arguments);
    var length = _.max(_.pluck(args, 'length'));
    var