client/lib/underscore.js
changeset 262 f6d0fa1db02a
parent 211 d87f6bdee43d
--- a/client/lib/underscore.js	Thu Feb 13 13:30:32 2014 +0100
+++ b/client/lib/underscore.js	Thu Feb 13 16:38:51 2014 +0100
@@ -1,6 +1,6 @@
-//     Underscore.js 1.5.2
+//     Underscore.js 1.6.0
 //     http://underscorejs.org
-//     (c) 2009-2013 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+//     (c) 2009-2014 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
 //     Underscore may be freely distributed under the MIT license.
 
 (function() {
@@ -65,7 +65,7 @@
   }
 
   // Current version.
-  _.VERSION = '1.5.2';
+  _.VERSION = '1.6.0';
 
   // Collection Functions
   // --------------------
@@ -74,7 +74,7 @@
   // Handles objects with the built-in `forEach`, arrays, and raw objects.
   // Delegates to **ECMAScript 5**'s native `forEach` if available.
   var each = _.each = _.forEach = function(obj, iterator, context) {
-    if (obj == null) return;
+    if (obj == null) return obj;
     if (nativeForEach && obj.forEach === nativeForEach) {
       obj.forEach(iterator, context);
     } else if (obj.length === +obj.length) {
@@ -87,6 +87,7 @@
         if (iterator.call(context, obj[keys[i]], keys[i], obj) === breaker) return;
       }
     }
+    return obj;
   };
 
   // Return the results of applying the iterator to each element.
@@ -152,10 +153,10 @@
   };
 
   // Return the first value which passes a truth test. Aliased as `detect`.
-  _.find = _.detect = function(obj, iterator, context) {
+  _.find = _.detect = function(obj, predicate, context) {
     var result;
     any(obj, function(value, index, list) {
-      if (iterator.call(context, value, index, list)) {
+      if (predicate.call(context, value, index, list)) {
         result = value;
         return true;
       }
@@ -166,33 +167,33 @@
   // Return all the elements that pass a truth test.
   // Delegates to **ECMAScript 5**'s native `filter` if available.
   // Aliased as `select`.
-  _.filter = _.select = function(obj, iterator, context) {
+  _.filter = _.select = function(obj, predicate, context) {
     var results = [];
     if (obj == null) return results;
-    if (nativeFilter && obj.filter === nativeFilter) return obj.filter(iterator, context);
+    if (nativeFilter && obj.filter === nativeFilter) return obj.filter(predicate, context);
     each(obj, function(value, index, list) {
-      if (iterator.call(context, value, index, list)) results.push(value);
+      if (predicate.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) {
+  _.reject = function(obj, predicate, context) {
     return _.filter(obj, function(value, index, list) {
-      return !iterator.call(context, value, index, list);
+      return !predicate.call(context, value, index, list);
     }, context);
   };
 
   // Determine whether all of the elements match a truth test.
   // Delegates to **ECMAScript 5**'s native `every` if available.
   // Aliased as `all`.
-  _.every = _.all = function(obj, iterator, context) {
-    iterator || (iterator = _.identity);
+  _.every = _.all = function(obj, predicate, context) {
+    predicate || (predicate = _.identity);
     var result = true;
     if (obj == null) return result;
-    if (nativeEvery && obj.every === nativeEvery) return obj.every(iterator, context);
+    if (nativeEvery && obj.every === nativeEvery) return obj.every(predicate, context);
     each(obj, function(value, index, list) {
-      if (!(result = result && iterator.call(context, value, index, list))) return breaker;
+      if (!(result = result && predicate.call(context, value, index, list))) return breaker;
     });
     return !!result;
   };
@@ -200,13 +201,13 @@
   // Determine if at least one element in the object matches a truth test.
   // Delegates to **ECMAScript 5**'s native `some` if available.
   // Aliased as `any`.
-  var any = _.some = _.any = function(obj, iterator, context) {
-    iterator || (iterator = _.identity);
+  var any = _.some = _.any = function(obj, predicate, context) {
+    predicate || (predicate = _.identity);
     var result = false;
     if (obj == null) return result;
-    if (nativeSome && obj.some === nativeSome) return obj.some(iterator, context);
+    if (nativeSome && obj.some === nativeSome) return obj.some(predicate, context);
     each(obj, function(value, index, list) {
-      if (result || (result = iterator.call(context, value, index, list))) return breaker;
+      if (result || (result = predicate.call(context, value, index, list))) return breaker;
     });
     return !!result;
   };
@@ -232,25 +233,19 @@
 
   // 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 _.map(obj, _.property(key));
   };
 
   // Convenience version of a common use case of `filter`: selecting only objects
   // containing specific `key:value` pairs.
-  _.where = function(obj, attrs, first) {
-    if (_.isEmpty(attrs)) return first ? void 0 : [];
-    return _[first ? 'find' : 'filter'](obj, function(value) {
-      for (var key in attrs) {
-        if (attrs[key] !== value[key]) return false;
-      }
-      return true;
-    });
+  _.where = function(obj, attrs) {
+    return _.filter(obj, _.matches(attrs));
   };
 
   // Convenience version of a common use case of `find`: getting the first object
   // containing specific `key:value` pairs.
   _.findWhere = function(obj, attrs) {
-    return _.where(obj, attrs, true);
+    return _.find(obj, _.matches(attrs));
   };
 
   // Return the maximum element or (element-based computation).
@@ -260,13 +255,15 @@
     if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
       return Math.max.apply(Math, obj);
     }
-    if (!iterator && _.isEmpty(obj)) return -Infinity;
-    var result = {computed : -Infinity, value: -Infinity};
+    var result = -Infinity, lastComputed = -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});
+      if (computed > lastComputed) {
+        result = value;
+        lastComputed = computed;
+      }
     });
-    return result.value;
+    return result;
   };
 
   // Return the minimum element (or element-based computation).
@@ -274,16 +271,18 @@
     if (!iterator && _.isArray(obj) && obj[0] === +obj[0] && obj.length < 65535) {
       return Math.min.apply(Math, obj);
     }
-    if (!iterator && _.isEmpty(obj)) return Infinity;
-    var result = {computed : Infinity, value: Infinity};
+    var result = Infinity, lastComputed = 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});
+      if (computed < lastComputed) {
+        result = value;
+        lastComputed = computed;
+      }
     });
-    return result.value;
+    return result;
   };
 
-  // Shuffle an array, using the modern version of the 
+  // Shuffle an array, using the modern version of the
   // [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher–Yates_shuffle).
   _.shuffle = function(obj) {
     var rand;
@@ -297,11 +296,12 @@
     return shuffled;
   };
 
-  // Sample **n** random values from an array.
-  // If **n** is not specified, returns a single random element from the array.
+  // Sample **n** random values from a collection.
+  // If **n** is not specified, returns a single random element.
   // The internal `guard` argument allows it to work with `map`.
   _.sample = function(obj, n, guard) {
-    if (arguments.length < 2 || guard) {
+    if (n == null || guard) {
+      if (obj.length !== +obj.length) obj = _.values(obj);
       return obj[_.random(obj.length - 1)];
     }
     return _.shuffle(obj).slice(0, Math.max(0, n));
@@ -309,12 +309,14 @@
 
   // An internal function to generate lookup iterators.
   var lookupIterator = function(value) {
-    return _.isFunction(value) ? value : function(obj){ return obj[value]; };
+    if (value == null) return _.identity;
+    if (_.isFunction(value)) return value;
+    return _.property(value);
   };
 
   // Sort the object's values by a criterion produced by an iterator.
-  _.sortBy = function(obj, value, context) {
-    var iterator = lookupIterator(value);
+  _.sortBy = function(obj, iterator, context) {
+    iterator = lookupIterator(iterator);
     return _.pluck(_.map(obj, function(value, index, list) {
       return {
         value: value,
@@ -334,9 +336,9 @@
 
   // An internal function used for aggregate "group by" operations.
   var group = function(behavior) {
-    return function(obj, value, context) {
+    return function(obj, iterator, context) {
       var result = {};
-      var iterator = value == null ? _.identity : lookupIterator(value);
+      iterator = lookupIterator(iterator);
       each(obj, function(value, index) {
         var key = iterator.call(context, value, index, obj);
         behavior(result, key, value);
@@ -348,7 +350,7 @@
   // Groups the object's values by a criterion. Pass either a string attribute
   // to group by, or a function that returns the criterion.
   _.groupBy = group(function(result, key, value) {
-    (_.has(result, key) ? result[key] : (result[key] = [])).push(value);
+    _.has(result, key) ? result[key].push(value) : result[key] = [value];
   });
 
   // Indexes the object's values by a criterion, similar to `groupBy`, but for
@@ -367,7 +369,7 @@
   // Use a comparator function to figure out the smallest index at which
   // an object should be inserted so as to maintain order. Uses binary search.
   _.sortedIndex = function(array, obj, iterator, context) {
-    iterator = iterator == null ? _.identity : lookupIterator(iterator);
+    iterator = lookupIterator(iterator);
     var value = iterator.call(context, obj);
     var low = 0, high = array.length;
     while (low < high) {
@@ -399,7 +401,9 @@
   // allows it to work with `_.map`.
   _.first = _.head = _.take = function(array, n, guard) {
     if (array == null) return void 0;
-    return (n == null) || guard ? array[0] : slice.call(array, 0, n);
+    if ((n == null) || guard) return array[0];
+    if (n < 0) return [];
+    return slice.call(array, 0, n);
   };
 
   // Returns everything but the last entry of the array. Especially useful on
@@ -414,11 +418,8 @@
   // values in the array. The **guard** check allows it to work with `_.map`.
   _.last = function(array, n, guard) {
     if (array == null) return void 0;
-    if ((n == null) || guard) {
-      return array[array.length - 1];
-    } else {
-      return slice.call(array, Math.max(array.length - n, 0));
-    }
+    if ((n == null) || guard) return array[array.length - 1];
+    return slice.call(array, Math.max(array.length - n, 0));
   };
 
   // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
@@ -459,6 +460,17 @@
     return _.difference(array, slice.call(arguments, 1));
   };
 
+  // Split an array into two arrays: one whose elements all satisfy the given
+  // predicate, and one whose elements all do not satisfy the predicate.
+  _.partition = function(array, predicate, context) {
+    predicate = lookupIterator(predicate);
+    var pass = [], fail = [];
+    each(array, function(elem) {
+      (predicate.call(context, elem) ? pass : fail).push(elem);
+    });
+    return [pass, fail];
+  };
+
   // Produce a duplicate-free version of the array. If the array has already
   // been sorted, you have the option of using a faster algorithm.
   // Aliased as `unique`.
@@ -492,7 +504,7 @@
     var rest = slice.call(arguments, 1);
     return _.filter(_.uniq(array), function(item) {
       return _.every(rest, function(other) {
-        return _.indexOf(other, item) >= 0;
+        return _.contains(other, item);
       });
     });
   };
@@ -507,7 +519,7 @@
   // Zip together multiple lists into a single array -- elements that share
   // an index go together.
   _.zip = function() {
-    var length = _.max(_.pluck(arguments, "length").concat(0));
+    var length = _.max(_.pluck(arguments, 'length').concat(0));
     var results = new Array(length);
     for (var i = 0; i < length; i++) {
       results[i] = _.pluck(arguments, '' + i);
@@ -613,19 +625,27 @@
   };
 
   // Partially apply a function by creating a version that has had some of its
-  // arguments pre-filled, without changing its dynamic `this` context.
+  // arguments pre-filled, without changing its dynamic `this` context. _ acts
+  // as a placeholder, allowing any combination of arguments to be pre-filled.
   _.partial = function(func) {
-    var args = slice.call(arguments, 1);
+    var boundArgs = slice.call(arguments, 1);
     return function() {
-      return func.apply(this, args.concat(slice.call(arguments)));
+      var position = 0;
+      var args = boundArgs.slice();
+      for (var i = 0, length = args.length; i < length; i++) {
+        if (args[i] === _) args[i] = arguments[position++];
+      }
+      while (position < arguments.length) args.push(arguments[position++]);
+      return func.apply(this, args);
     };
   };
 
-  // Bind all of an object's methods to that object. Useful for ensuring that
-  // all callbacks defined on an object belong to it.
+  // Bind a number of an object's methods to that object. Remaining arguments
+  // are the method names to be bound. Useful for ensuring that all callbacks
+  // defined on an object belong to it.
   _.bindAll = function(obj) {
     var funcs = slice.call(arguments, 1);
-    if (funcs.length === 0) throw new Error("bindAll must be passed function names");
+    if (funcs.length === 0) throw new Error('bindAll must be passed function names');
     each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
     return obj;
   };
@@ -664,12 +684,13 @@
     var previous = 0;
     options || (options = {});
     var later = function() {
-      previous = options.leading === false ? 0 : new Date;
+      previous = options.leading === false ? 0 : _.now();
       timeout = null;
       result = func.apply(context, args);
+      context = args = null;
     };
     return function() {
-      var now = new Date;
+      var now = _.now();
       if (!previous && options.leading === false) previous = now;
       var remaining = wait - (now - previous);
       context = this;
@@ -679,6 +700,7 @@
         timeout = null;
         previous = now;
         result = func.apply(context, args);
+        context = args = null;
       } else if (!timeout && options.trailing !== false) {
         timeout = setTimeout(later, remaining);
       }
@@ -692,24 +714,33 @@
   // leading edge, instead of the trailing.
   _.debounce = function(func, wait, immediate) {
     var timeout, args, context, timestamp, result;
+
+    var later = function() {
+      var last = _.now() - timestamp;
+      if (last < wait) {
+        timeout = setTimeout(later, wait - last);
+      } else {
+        timeout = null;
+        if (!immediate) {
+          result = func.apply(context, args);
+          context = args = null;
+        }
+      }
+    };
+
     return function() {
       context = this;
       args = arguments;
-      timestamp = new Date();
-      var later = function() {
-        var last = (new Date()) - timestamp;
-        if (last < wait) {
-          timeout = setTimeout(later, wait - last);
-        } else {
-          timeout = null;
-          if (!immediate) result = func.apply(context, args);
-        }
-      };
+      timestamp = _.now();
       var callNow = immediate && !timeout;
       if (!timeout) {
         timeout = setTimeout(later, wait);
       }
-      if (callNow) result = func.apply(context, args);
+      if (callNow) {
+        result = func.apply(context, args);
+        context = args = null;
+      }
+
       return result;
     };
   };
@@ -731,11 +762,7 @@
   // allowing you to adjust arguments, run code before and after, and
   // conditionally execute the original function.
   _.wrap = function(func, wrapper) {
-    return function() {
-      var args = [func];
-      push.apply(args, arguments);
-      return wrapper.apply(this, args);
-    };
+    return _.partial(wrapper, func);
   };
 
   // Returns a function that is the composition of a list of functions, each
@@ -765,8 +792,9 @@
 
   // Retrieve the names of an object's properties.
   // Delegates to **ECMAScript 5**'s native `Object.keys`
-  _.keys = nativeKeys || function(obj) {
-    if (obj !== Object(obj)) throw new TypeError('Invalid object');
+  _.keys = function(obj) {
+    if (!_.isObject(obj)) return [];
+    if (nativeKeys) return nativeKeys(obj);
     var keys = [];
     for (var key in obj) if (_.has(obj, key)) keys.push(key);
     return keys;
@@ -921,7 +949,8 @@
     // from different frames are.
     var aCtor = a.constructor, bCtor = b.constructor;
     if (aCtor !== bCtor && !(_.isFunction(aCtor) && (aCtor instanceof aCtor) &&
-                             _.isFunction(bCtor) && (bCtor instanceof bCtor))) {
+                             _.isFunction(bCtor) && (bCtor instanceof bCtor))
+                        && ('constructor' in a && 'constructor' in b)) {
       return false;
     }
     // Add the first object to the stack of traversed objects.
@@ -1061,6 +1090,30 @@
     return value;
   };
 
+  _.constant = function(value) {
+    return function () {
+      return value;
+    };
+  };
+
+  _.property = function(key) {
+    return function(obj) {
+      return obj[key];
+    };
+  };
+
+  // Returns a predicate for checking whether an object has a given set of `key:value` pairs.
+  _.matches = function(attrs) {
+    return function(obj) {
+      if (obj === attrs) return true; //avoid comparing an object to itself.
+      for (var key in attrs) {
+        if (attrs[key] !== obj[key])
+          return false;
+      }
+      return true;
+    }
+  };
+
   // Run a function **n** times.
   _.times = function(n, iterator, context) {
     var accum = Array(Math.max(0, n));
@@ -1077,6 +1130,9 @@
     return min + Math.floor(Math.random() * (max - min + 1));
   };
 
+  // A (possibly faster) way to get the current timestamp as an integer.
+  _.now = Date.now || function() { return new Date().getTime(); };
+
   // List of HTML entities for escaping.
   var entityMap = {
     escape: {
@@ -1273,4 +1329,16 @@
 
   });
 
+  // AMD registration happens at the end for compatibility with AMD loaders
+  // that may not enforce next-turn semantics on modules. Even though general
+  // practice for AMD registration is to be anonymous, underscore registers
+  // as a named module because, like jQuery, it is a base library that is
+  // popular enough to be bundled in a third party lib, but not be part of
+  // an AMD load request. Those cases could generate an error when an
+  // anonymous define() is called outside of a loader request.
+  if (typeof define === 'function' && define.amd) {
+    define('underscore', [], function() {
+      return _;
+    });
+  }
 }).call(this);