Add _.constant, _.mapValues, and _.xor.

dist/lodash.compat.js

@@ -2483,15 +2483,15 @@
      * @memberOf _
      * @category Objects
      * @param {Object} object The object to inspect.
-     * @param {string} prop The name of the property to check.
+     * @param {string} key The name of the property to check.
      * @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, prop) {
-      return object ? hasOwnProperty.call(object, prop) : false;
+    function has(object, key) {
+      return object ? hasOwnProperty.call(object, key) : false;
     }
 
     /**
@@ -2896,6 +2896,52 @@
       return typeof value == 'undefined';
     }
 
+    /**
+     * Creates an object with the same keys as `object` and values generated by
+     * running each own enumerable property of `object` through the callback.
+     * The callback is bound to `thisArg` and invoked with three arguments;
+     * (value, key, object).
+     *
+     * If a property name is provided for `callback` the created "_.pluck" style
+     * callback will return the property value of the given element.
+     *
+     * If an object is provided for `callback` the created "_.where" style callback
+     * will return `true` for elements that have the properties of the given object,
+     * else `false`.
+     *
+     * @static
+     * @memberOf _
+     * @category Objects
+     * @param {Object} object The object to iterate over.
+     * @param {Function|Object|string} [callback=identity] The function called
+     *  per iteration. If a property name or object is provided it will be used
+     *  to create a "_.pluck" or "_.where" style callback, respectively.
+     * @param {*} [thisArg] The `this` binding of `callback`.
+     * @returns {Array} Returns a new object with values of the results of each `callback` execution.
+     * @example
+     *
+     * _.mapValues({ 'a': 1, 'b': 2, 'c': 3} , function(num) { return num * 3; });
+     * // => { 'a': 3, 'b': 6, 'c': 9 }
+     *
+     * var characters = {
+     *   'fred': { 'name': 'fred', 'age': 40 },
+     *   'pebbles': { 'name': 'pebbles', 'age': 1 }
+     * };
+     *
+     * // using "_.pluck" callback shorthand
+     * _.mapValues(characters, 'age');
+     * // => { 'fred': 40, 'pebbles': 1 }
+     */
+    function mapValues(object, callback, thisArg) {
+      var result = {};
+      callback = lodash.createCallback(callback, thisArg, 3);
+
+      forOwn(object, function(value, key, object) {
+        result[key] = callback(value, key, object);
+      });
+      return result;
+    }
+
     /**
      * Recursively merges own enumerable properties of the source object(s), that
      * don't resolve to `undefined` into the destination object. Subsequent sources
@@ -3111,11 +3157,11 @@
 
     /**
      * An alternative to `_.reduce` this method transforms `object` to a new
-     * `accumulator` object which is the result of running each of its elements
-     * through a callback, with each callback execution potentially mutating
-     * the `accumulator` object. The callback is bound to `thisArg` and invoked
-     * with four arguments; (accumulator, value, key, object). Callbacks may exit
-     * iteration early by explicitly returning `false`.
+     * `accumulator` object which is the result of running each of its own
+     * enumerable properties through a callback, with each callback execution
+     * potentially mutating the `accumulator` object. The callback is bound to
+     * `thisArg` and invoked with four arguments; (accumulator, value, key, object).
+     * Callbacks may exit iteration early by explicitly returning `false`.
      *
      * @static
      * @memberOf _
@@ -4740,29 +4786,34 @@
      * @memberOf _
      * @category Arrays
      * @param {...Array} [array] The arrays to inspect.
-     * @returns {Array} Returns an array of composite values.
+     * @returns {Array} Returns an array of shared values.
      * @example
      *
-     * _.intersection([1, 2, 3], [101, 2, 1, 10], [2, 1]);
+     * _.intersection([1, 2, 3], [5, 2, 1, 4], [2, 1]);
      * // => [1, 2]
      */
-    function intersection(array) {
-      var args = arguments,
-          argsLength = args.length,
+    function intersection() {
+      var args = [],
           argsIndex = -1,
+          argsLength = arguments.length,
           caches = getArray(),
-          index = -1,
           indexOf = getIndexOf(),
-          length = array ? array.length : 0,
-          result = [],
+          trustIndexOf = indexOf === baseIndexOf,
           seen = getArray();
 
       while (++argsIndex < argsLength) {
-        var value = args[argsIndex];
-        caches[argsIndex] = indexOf === baseIndexOf &&
-          (value ? value.length : 0) >= largeArraySize &&
-          createCache(argsIndex ? args[argsIndex] : seen);
+        var value = arguments[argsIndex];
+        if (isArray(value) || isArguments(value)) {
+          args.push(value);
+          caches.push(trustIndexOf && value.length >= largeArraySize &&
+            createCache(argsIndex ? args[argsIndex] : seen));
+        }
       }
+      var array = args[0],
+          index = -1,
+          length = array ? array.length : 0,
+          result = [];
+
       outer:
       while (++index < length) {
         var cache = caches[0];
@@ -5179,13 +5230,13 @@
      * @memberOf _
      * @category Arrays
      * @param {...Array} [array] The arrays to inspect.
-     * @returns {Array} Returns an array of composite values.
+     * @returns {Array} Returns an array of combined values.
      * @example
      *
-     * _.union([1, 2, 3], [101, 2, 1, 10], [2, 1]);
-     * // => [1, 2, 3, 101, 10]
+     * _.union([1, 2, 3], [5, 2, 1, 4], [2, 1]);
+     * // => [1, 2, 3, 5, 4]
      */
-    function union(array) {
+    function union() {
       return baseUniq(baseFlatten(arguments, true, true));
     }
 
@@ -5265,6 +5316,37 @@
       return baseDifference(array, slice(arguments, 1));
     }
 
+    /**
+     * Creates an array that is the smymetric difference of the provided arrays.
+     * See http://en.wikipedia.org/wiki/Symmetric_difference.
+     *
+     * @static
+     * @memberOf _
+     * @category Arrays
+     * @param {...Array} [array] The arrays to inspect.
+     * @returns {Array} Returns an array of values.
+     * @example
+     *
+     * _.xor([1, 2, 3], [5, 2, 1, 4]);
+     * // => [3, 5, 4]
+     *
+     * _.xor([1, 2, 5], [2, 3, 5], [3, 4, 5]);
+     * // => [1, 4, 5]
+     */
+    function xor() {
+      var index = 0,
+          length = arguments.length,
+          result = arguments[0] || [];
+
+      while (++index < length) {
+        var array = arguments[index];
+        if (isArray(array) || isArguments(array)) {
+          result = baseUniq(baseDifference(result, array).concat(baseDifference(array, result)));
+        }
+      }
+      return result;
+    }
+
     /**
      * Creates an array of grouped elements, the first of which contains the first
      * elements of the given arrays, the second of which contains the second
@@ -5971,6 +6053,27 @@
 
     /*--------------------------------------------------------------------------*/
 
+    /**
+     * Creates a function that returns `value`.
+     *
+     * @static
+     * @memberOf _
+     * @category Utilities
+     * @param {*} value The value to return from the new function.
+     * @returns {Function} Returns the new function.
+     * @example
+     *
+     * var object = { 'name': 'fred' };
+     * var getter = _.constant(object);
+     * getter() === object;
+     * // => true
+     */
+    function constant(value) {
+      return function() {
+        return value;
+      };
+    }
+
     /**
      * Produces a callback bound to an optional `thisArg`. If `func` is a property
      * name the created callback will return the property value for a given element.
@@ -6200,14 +6303,14 @@
     };
 
     /**
-     * Creates a "_.pluck" style function, which returns the `prop` value of a
+     * Creates a "_.pluck" style function, which returns the `key` value of a
      * given object.
      *
      * @static
      * @memberOf _
      * @category Utilities
-     * @param {string} prop The name of the property to retrieve.
-     * @returns {*} Returns the new function.
+     * @param {string} key The name of the property to retrieve.
+     * @returns {Function} Returns the new function.
      * @example
      *
      * var characters = [
@@ -6223,9 +6326,9 @@
      * _.sortBy(characters, getName);
      * // => [{ 'name': 'barney', 'age': 36 }, { 'name': 'fred',   'age': 40 }]
      */
-    function property(prop) {
+    function property(key) {
       return function(object) {
-        return object[prop];
+        return object[key];
       };
     }
 
@@ -6288,7 +6391,7 @@
     }
 
     /**
-     * Resolves the value of `prop` on `object`. If `prop` is a function
+     * Resolves the value of property `key` on `object`. If `key` is a function
      * it will be invoked with the `this` binding of `object` and its result returned,
      * else the property value is returned. If `object` is falsey then `undefined`
      * is returned.
@@ -6297,7 +6400,7 @@
      * @memberOf _
      * @category Utilities
      * @param {Object} object The object to inspect.
-     * @param {string} prop The name of the property to resolve.
+     * @param {string} key The name of the property to resolve.
      * @returns {*} Returns the resolved value.
      * @example
      *
@@ -6314,10 +6417,10 @@
      * _.result(object, 'stuff');
      * // => 'nonsense'
      */
-    function result(object, prop) {
+    function result(object, key) {
       if (object) {
-        var value = object[prop];
-        return isFunction(value) ? object[prop]() : value;
+        var value = object[key];
+        return isFunction(value) ? object[key]() : value;
       }
     }
 
@@ -6714,6 +6817,7 @@
     lodash.chain = chain;
     lodash.compact = compact;
     lodash.compose = compose;
+    lodash.constant = constant;
     lodash.countBy = countBy;
     lodash.create = create;
     lodash.createCallback = createCallback;
@@ -6740,6 +6844,7 @@
     lodash.invoke = invoke;
     lodash.keys = keys;
     lodash.map = map;
+    lodash.mapValues = mapValues;
     lodash.max = max;
     lodash.memoize = memoize;
     lodash.merge = merge;
@@ -6770,6 +6875,7 @@
     lodash.where = where;
     lodash.without = without;
     lodash.wrap = wrap;
+    lodash.xor = xor;
     lodash.zip = zip;
     lodash.zipObject = zipObject;