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+// Copyright 2006 The Closure Library Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS-IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/**
+ * @fileoverview Utilities for manipulating arrays.
+ *
+ * @author arv@google.com (Erik Arvidsson)
+ */
+
+
+goog.provide('goog.array');
+
+goog.require('goog.asserts');
+
+
+/**
+ * @define {boolean} NATIVE_ARRAY_PROTOTYPES indicates whether the code should
+ * rely on Array.prototype functions, if available.
+ *
+ * The Array.prototype functions can be defined by external libraries like
+ * Prototype and setting this flag to false forces closure to use its own
+ * goog.array implementation.
+ *
+ * If your javascript can be loaded by a third party site and you are wary about
+ * relying on the prototype functions, specify
+ * "--define goog.NATIVE_ARRAY_PROTOTYPES=false" to the JSCompiler.
+ *
+ * Setting goog.TRUSTED_SITE to false will automatically set
+ * NATIVE_ARRAY_PROTOTYPES to false.
+ */
+goog.define('goog.NATIVE_ARRAY_PROTOTYPES', goog.TRUSTED_SITE);
+
+
+/**
+ * @define {boolean} If true, JSCompiler will use the native implementation of
+ * array functions where appropriate (e.g., {@code Array#filter}) and remove the
+ * unused pure JS implementation.
+ */
+goog.define('goog.array.ASSUME_NATIVE_FUNCTIONS', false);
+
+
+/**
+ * Returns the last element in an array without removing it.
+ * Same as goog.array.last.
+ * @param {IArrayLike<T>|string} array The array.
+ * @return {T} Last item in array.
+ * @template T
+ */
+goog.array.peek = function(array) {
+ return array[array.length - 1];
+};
+
+
+/**
+ * Returns the last element in an array without removing it.
+ * Same as goog.array.peek.
+ * @param {IArrayLike<T>|string} array The array.
+ * @return {T} Last item in array.
+ * @template T
+ */
+goog.array.last = goog.array.peek;
+
+// NOTE(arv): Since most of the array functions are generic it allows you to
+// pass an array-like object. Strings have a length and are considered array-
+// like. However, the 'in' operator does not work on strings so we cannot just
+// use the array path even if the browser supports indexing into strings. We
+// therefore end up splitting the string.
+
+
+/**
+ * Returns the index of the first element of an array with a specified value, or
+ * -1 if the element is not present in the array.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-indexof}
+ *
+ * @param {IArrayLike<T>|string} arr The array to be searched.
+ * @param {T} obj The object for which we are searching.
+ * @param {number=} opt_fromIndex The index at which to start the search. If
+ * omitted the search starts at index 0.
+ * @return {number} The index of the first matching array element.
+ * @template T
+ */
+goog.array.indexOf = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.indexOf) ?
+ function(arr, obj, opt_fromIndex) {
+ goog.asserts.assert(arr.length != null);
+
+ return Array.prototype.indexOf.call(arr, obj, opt_fromIndex);
+ } :
+ function(arr, obj, opt_fromIndex) {
+ var fromIndex = opt_fromIndex == null ?
+ 0 :
+ (opt_fromIndex < 0 ? Math.max(0, arr.length + opt_fromIndex) :
+ opt_fromIndex);
+
+ if (goog.isString(arr)) {
+ // Array.prototype.indexOf uses === so only strings should be found.
+ if (!goog.isString(obj) || obj.length != 1) {
+ return -1;
+ }
+ return arr.indexOf(obj, fromIndex);
+ }
+
+ for (var i = fromIndex; i < arr.length; i++) {
+ if (i in arr && arr[i] === obj) return i;
+ }
+ return -1;
+ };
+
+
+/**
+ * Returns the index of the last element of an array with a specified value, or
+ * -1 if the element is not present in the array.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-lastindexof}
+ *
+ * @param {!IArrayLike<T>|string} arr The array to be searched.
+ * @param {T} obj The object for which we are searching.
+ * @param {?number=} opt_fromIndex The index at which to start the search. If
+ * omitted the search starts at the end of the array.
+ * @return {number} The index of the last matching array element.
+ * @template T
+ */
+goog.array.lastIndexOf = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.lastIndexOf) ?
+ function(arr, obj, opt_fromIndex) {
+ goog.asserts.assert(arr.length != null);
+
+ // Firefox treats undefined and null as 0 in the fromIndex argument which
+ // leads it to always return -1
+ var fromIndex = opt_fromIndex == null ? arr.length - 1 : opt_fromIndex;
+ return Array.prototype.lastIndexOf.call(arr, obj, fromIndex);
+ } :
+ function(arr, obj, opt_fromIndex) {
+ var fromIndex = opt_fromIndex == null ? arr.length - 1 : opt_fromIndex;
+
+ if (fromIndex < 0) {
+ fromIndex = Math.max(0, arr.length + fromIndex);
+ }
+
+ if (goog.isString(arr)) {
+ // Array.prototype.lastIndexOf uses === so only strings should be found.
+ if (!goog.isString(obj) || obj.length != 1) {
+ return -1;
+ }
+ return arr.lastIndexOf(obj, fromIndex);
+ }
+
+ for (var i = fromIndex; i >= 0; i--) {
+ if (i in arr && arr[i] === obj) return i;
+ }
+ return -1;
+ };
+
+
+/**
+ * Calls a function for each element in an array. Skips holes in the array.
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-foreach}
+ *
+ * @param {IArrayLike<T>|string} arr Array or array like object over
+ * which to iterate.
+ * @param {?function(this: S, T, number, ?): ?} f The function to call for every
+ * element. This function takes 3 arguments (the element, the index and the
+ * array). The return value is ignored.
+ * @param {S=} opt_obj The object to be used as the value of 'this' within f.
+ * @template T,S
+ */
+goog.array.forEach = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.forEach) ?
+ function(arr, f, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+
+ Array.prototype.forEach.call(arr, f, opt_obj);
+ } :
+ function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = 0; i < l; i++) {
+ if (i in arr2) {
+ f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr);
+ }
+ }
+ };
+
+
+/**
+ * Calls a function for each element in an array, starting from the last
+ * element rather than the first.
+ *
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this: S, T, number, ?): ?} f The function to call for every
+ * element. This function
+ * takes 3 arguments (the element, the index and the array). The return
+ * value is ignored.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within f.
+ * @template T,S
+ */
+goog.array.forEachRight = function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = l - 1; i >= 0; --i) {
+ if (i in arr2) {
+ f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr);
+ }
+ }
+};
+
+
+/**
+ * Calls a function for each element in an array, and if the function returns
+ * true adds the element to a new array.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-filter}
+ *
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?):boolean} f The function to call for
+ * every element. This function
+ * takes 3 arguments (the element, the index and the array) and must
+ * return a Boolean. If the return value is true the element is added to the
+ * result array. If it is false the element is not included.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within f.
+ * @return {!Array<T>} a new array in which only elements that passed the test
+ * are present.
+ * @template T,S
+ */
+goog.array.filter = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.filter) ?
+ function(arr, f, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+
+ return Array.prototype.filter.call(arr, f, opt_obj);
+ } :
+ function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var res = [];
+ var resLength = 0;
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = 0; i < l; i++) {
+ if (i in arr2) {
+ var val = arr2[i]; // in case f mutates arr2
+ if (f.call(/** @type {?} */ (opt_obj), val, i, arr)) {
+ res[resLength++] = val;
+ }
+ }
+ }
+ return res;
+ };
+
+
+/**
+ * Calls a function for each element in an array and inserts the result into a
+ * new array.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-map}
+ *
+ * @param {IArrayLike<VALUE>|string} arr Array or array like object
+ * over which to iterate.
+ * @param {function(this:THIS, VALUE, number, ?): RESULT} f The function to call
+ * for every element. This function takes 3 arguments (the element,
+ * the index and the array) and should return something. The result will be
+ * inserted into a new array.
+ * @param {THIS=} opt_obj The object to be used as the value of 'this' within f.
+ * @return {!Array<RESULT>} a new array with the results from f.
+ * @template THIS, VALUE, RESULT
+ */
+goog.array.map = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.map) ?
+ function(arr, f, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+
+ return Array.prototype.map.call(arr, f, opt_obj);
+ } :
+ function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var res = new Array(l);
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = 0; i < l; i++) {
+ if (i in arr2) {
+ res[i] = f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr);
+ }
+ }
+ return res;
+ };
+
+
+/**
+ * Passes every element of an array into a function and accumulates the result.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-reduce}
+ *
+ * For example:
+ * var a = [1, 2, 3, 4];
+ * goog.array.reduce(a, function(r, v, i, arr) {return r + v;}, 0);
+ * returns 10
+ *
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {function(this:S, R, T, number, ?) : R} f The function to call for
+ * every element. This function
+ * takes 4 arguments (the function's previous result or the initial value,
+ * the value of the current array element, the current array index, and the
+ * array itself)
+ * function(previousValue, currentValue, index, array).
+ * @param {?} val The initial value to pass into the function on the first call.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within f.
+ * @return {R} Result of evaluating f repeatedly across the values of the array.
+ * @template T,S,R
+ */
+goog.array.reduce = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.reduce) ?
+ function(arr, f, val, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+ if (opt_obj) {
+ f = goog.bind(f, opt_obj);
+ }
+ return Array.prototype.reduce.call(arr, f, val);
+ } :
+ function(arr, f, val, opt_obj) {
+ var rval = val;
+ goog.array.forEach(arr, function(val, index) {
+ rval = f.call(/** @type {?} */ (opt_obj), rval, val, index, arr);
+ });
+ return rval;
+ };
+
+
+/**
+ * Passes every element of an array into a function and accumulates the result,
+ * starting from the last element and working towards the first.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-reduceright}
+ *
+ * For example:
+ * var a = ['a', 'b', 'c'];
+ * goog.array.reduceRight(a, function(r, v, i, arr) {return r + v;}, '');
+ * returns 'cba'
+ *
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, R, T, number, ?) : R} f The function to call for
+ * every element. This function
+ * takes 4 arguments (the function's previous result or the initial value,
+ * the value of the current array element, the current array index, and the
+ * array itself)
+ * function(previousValue, currentValue, index, array).
+ * @param {?} val The initial value to pass into the function on the first call.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within f.
+ * @return {R} Object returned as a result of evaluating f repeatedly across the
+ * values of the array.
+ * @template T,S,R
+ */
+goog.array.reduceRight = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.reduceRight) ?
+ function(arr, f, val, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+ goog.asserts.assert(f != null);
+ if (opt_obj) {
+ f = goog.bind(f, opt_obj);
+ }
+ return Array.prototype.reduceRight.call(arr, f, val);
+ } :
+ function(arr, f, val, opt_obj) {
+ var rval = val;
+ goog.array.forEachRight(arr, function(val, index) {
+ rval = f.call(/** @type {?} */ (opt_obj), rval, val, index, arr);
+ });
+ return rval;
+ };
+
+
+/**
+ * Calls f for each element of an array. If any call returns true, some()
+ * returns true (without checking the remaining elements). If all calls
+ * return false, some() returns false.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-some}
+ *
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call for
+ * for every element. This function takes 3 arguments (the element, the
+ * index and the array) and should return a boolean.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within f.
+ * @return {boolean} true if any element passes the test.
+ * @template T,S
+ */
+goog.array.some = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.some) ?
+ function(arr, f, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+
+ return Array.prototype.some.call(arr, f, opt_obj);
+ } :
+ function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = 0; i < l; i++) {
+ if (i in arr2 && f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr)) {
+ return true;
+ }
+ }
+ return false;
+ };
+
+
+/**
+ * Call f for each element of an array. If all calls return true, every()
+ * returns true. If any call returns false, every() returns false and
+ * does not continue to check the remaining elements.
+ *
+ * See {@link http://tinyurl.com/developer-mozilla-org-array-every}
+ *
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call for
+ * for every element. This function takes 3 arguments (the element, the
+ * index and the array) and should return a boolean.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within f.
+ * @return {boolean} false if any element fails the test.
+ * @template T,S
+ */
+goog.array.every = goog.NATIVE_ARRAY_PROTOTYPES &&
+ (goog.array.ASSUME_NATIVE_FUNCTIONS || Array.prototype.every) ?
+ function(arr, f, opt_obj) {
+ goog.asserts.assert(arr.length != null);
+
+ return Array.prototype.every.call(arr, f, opt_obj);
+ } :
+ function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = 0; i < l; i++) {
+ if (i in arr2 && !f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr)) {
+ return false;
+ }
+ }
+ return true;
+ };
+
+
+/**
+ * Counts the array elements that fulfill the predicate, i.e. for which the
+ * callback function returns true. Skips holes in the array.
+ *
+ * @param {!IArrayLike<T>|string} arr Array or array like object
+ * over which to iterate.
+ * @param {function(this: S, T, number, ?): boolean} f The function to call for
+ * every element. Takes 3 arguments (the element, the index and the array).
+ * @param {S=} opt_obj The object to be used as the value of 'this' within f.
+ * @return {number} The number of the matching elements.
+ * @template T,S
+ */
+goog.array.count = function(arr, f, opt_obj) {
+ var count = 0;
+ goog.array.forEach(arr, function(element, index, arr) {
+ if (f.call(/** @type {?} */ (opt_obj), element, index, arr)) {
+ ++count;
+ }
+ }, opt_obj);
+ return count;
+};
+
+
+/**
+ * Search an array for the first element that satisfies a given condition and
+ * return that element.
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call
+ * for every element. This function takes 3 arguments (the element, the
+ * index and the array) and should return a boolean.
+ * @param {S=} opt_obj An optional "this" context for the function.
+ * @return {T|null} The first array element that passes the test, or null if no
+ * element is found.
+ * @template T,S
+ */
+goog.array.find = function(arr, f, opt_obj) {
+ var i = goog.array.findIndex(arr, f, opt_obj);
+ return i < 0 ? null : goog.isString(arr) ? arr.charAt(i) : arr[i];
+};
+
+
+/**
+ * Search an array for the first element that satisfies a given condition and
+ * return its index.
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call for
+ * every element. This function
+ * takes 3 arguments (the element, the index and the array) and should
+ * return a boolean.
+ * @param {S=} opt_obj An optional "this" context for the function.
+ * @return {number} The index of the first array element that passes the test,
+ * or -1 if no element is found.
+ * @template T,S
+ */
+goog.array.findIndex = function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = 0; i < l; i++) {
+ if (i in arr2 && f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr)) {
+ return i;
+ }
+ }
+ return -1;
+};
+
+
+/**
+ * Search an array (in reverse order) for the last element that satisfies a
+ * given condition and return that element.
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call
+ * for every element. This function
+ * takes 3 arguments (the element, the index and the array) and should
+ * return a boolean.
+ * @param {S=} opt_obj An optional "this" context for the function.
+ * @return {T|null} The last array element that passes the test, or null if no
+ * element is found.
+ * @template T,S
+ */
+goog.array.findRight = function(arr, f, opt_obj) {
+ var i = goog.array.findIndexRight(arr, f, opt_obj);
+ return i < 0 ? null : goog.isString(arr) ? arr.charAt(i) : arr[i];
+};
+
+
+/**
+ * Search an array (in reverse order) for the last element that satisfies a
+ * given condition and return its index.
+ * @param {IArrayLike<T>|string} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call
+ * for every element. This function
+ * takes 3 arguments (the element, the index and the array) and should
+ * return a boolean.
+ * @param {S=} opt_obj An optional "this" context for the function.
+ * @return {number} The index of the last array element that passes the test,
+ * or -1 if no element is found.
+ * @template T,S
+ */
+goog.array.findIndexRight = function(arr, f, opt_obj) {
+ var l = arr.length; // must be fixed during loop... see docs
+ var arr2 = goog.isString(arr) ? arr.split('') : arr;
+ for (var i = l - 1; i >= 0; i--) {
+ if (i in arr2 && f.call(/** @type {?} */ (opt_obj), arr2[i], i, arr)) {
+ return i;
+ }
+ }
+ return -1;
+};
+
+
+/**
+ * Whether the array contains the given object.
+ * @param {IArrayLike<?>|string} arr The array to test for the presence of the
+ * element.
+ * @param {*} obj The object for which to test.
+ * @return {boolean} true if obj is present.
+ */
+goog.array.contains = function(arr, obj) {
+ return goog.array.indexOf(arr, obj) >= 0;
+};
+
+
+/**
+ * Whether the array is empty.
+ * @param {IArrayLike<?>|string} arr The array to test.
+ * @return {boolean} true if empty.
+ */
+goog.array.isEmpty = function(arr) {
+ return arr.length == 0;
+};
+
+
+/**
+ * Clears the array.
+ * @param {IArrayLike<?>} arr Array or array like object to clear.
+ */
+goog.array.clear = function(arr) {
+ // For non real arrays we don't have the magic length so we delete the
+ // indices.
+ if (!goog.isArray(arr)) {
+ for (var i = arr.length - 1; i >= 0; i--) {
+ delete arr[i];
+ }
+ }
+ arr.length = 0;
+};
+
+
+/**
+ * Pushes an item into an array, if it's not already in the array.
+ * @param {Array<T>} arr Array into which to insert the item.
+ * @param {T} obj Value to add.
+ * @template T
+ */
+goog.array.insert = function(arr, obj) {
+ if (!goog.array.contains(arr, obj)) {
+ arr.push(obj);
+ }
+};
+
+
+/**
+ * Inserts an object at the given index of the array.
+ * @param {IArrayLike<?>} arr The array to modify.
+ * @param {*} obj The object to insert.
+ * @param {number=} opt_i The index at which to insert the object. If omitted,
+ * treated as 0. A negative index is counted from the end of the array.
+ */
+goog.array.insertAt = function(arr, obj, opt_i) {
+ goog.array.splice(arr, opt_i, 0, obj);
+};
+
+
+/**
+ * Inserts at the given index of the array, all elements of another array.
+ * @param {IArrayLike<?>} arr The array to modify.
+ * @param {IArrayLike<?>} elementsToAdd The array of elements to add.
+ * @param {number=} opt_i The index at which to insert the object. If omitted,
+ * treated as 0. A negative index is counted from the end of the array.
+ */
+goog.array.insertArrayAt = function(arr, elementsToAdd, opt_i) {
+ goog.partial(goog.array.splice, arr, opt_i, 0).apply(null, elementsToAdd);
+};
+
+
+/**
+ * Inserts an object into an array before a specified object.
+ * @param {Array<T>} arr The array to modify.
+ * @param {T} obj The object to insert.
+ * @param {T=} opt_obj2 The object before which obj should be inserted. If obj2
+ * is omitted or not found, obj is inserted at the end of the array.
+ * @template T
+ */
+goog.array.insertBefore = function(arr, obj, opt_obj2) {
+ var i;
+ if (arguments.length == 2 || (i = goog.array.indexOf(arr, opt_obj2)) < 0) {
+ arr.push(obj);
+ } else {
+ goog.array.insertAt(arr, obj, i);
+ }
+};
+
+
+/**
+ * Removes the first occurrence of a particular value from an array.
+ * @param {IArrayLike<T>} arr Array from which to remove
+ * value.
+ * @param {T} obj Object to remove.
+ * @return {boolean} True if an element was removed.
+ * @template T
+ */
+goog.array.remove = function(arr, obj) {
+ var i = goog.array.indexOf(arr, obj);
+ var rv;
+ if ((rv = i >= 0)) {
+ goog.array.removeAt(arr, i);
+ }
+ return rv;
+};
+
+
+/**
+ * Removes the last occurrence of a particular value from an array.
+ * @param {!IArrayLike<T>} arr Array from which to remove value.
+ * @param {T} obj Object to remove.
+ * @return {boolean} True if an element was removed.
+ * @template T
+ */
+goog.array.removeLast = function(arr, obj) {
+ var i = goog.array.lastIndexOf(arr, obj);
+ if (i >= 0) {
+ goog.array.removeAt(arr, i);
+ return true;
+ }
+ return false;
+};
+
+
+/**
+ * Removes from an array the element at index i
+ * @param {IArrayLike<?>} arr Array or array like object from which to
+ * remove value.
+ * @param {number} i The index to remove.
+ * @return {boolean} True if an element was removed.
+ */
+goog.array.removeAt = function(arr, i) {
+ goog.asserts.assert(arr.length != null);
+
+ // use generic form of splice
+ // splice returns the removed items and if successful the length of that
+ // will be 1
+ return Array.prototype.splice.call(arr, i, 1).length == 1;
+};
+
+
+/**
+ * Removes the first value that satisfies the given condition.
+ * @param {IArrayLike<T>} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call
+ * for every element. This function
+ * takes 3 arguments (the element, the index and the array) and should
+ * return a boolean.
+ * @param {S=} opt_obj An optional "this" context for the function.
+ * @return {boolean} True if an element was removed.
+ * @template T,S
+ */
+goog.array.removeIf = function(arr, f, opt_obj) {
+ var i = goog.array.findIndex(arr, f, opt_obj);
+ if (i >= 0) {
+ goog.array.removeAt(arr, i);
+ return true;
+ }
+ return false;
+};
+
+
+/**
+ * Removes all values that satisfy the given condition.
+ * @param {IArrayLike<T>} arr Array or array
+ * like object over which to iterate.
+ * @param {?function(this:S, T, number, ?) : boolean} f The function to call
+ * for every element. This function
+ * takes 3 arguments (the element, the index and the array) and should
+ * return a boolean.
+ * @param {S=} opt_obj An optional "this" context for the function.
+ * @return {number} The number of items removed
+ * @template T,S
+ */
+goog.array.removeAllIf = function(arr, f, opt_obj) {
+ var removedCount = 0;
+ goog.array.forEachRight(arr, function(val, index) {
+ if (f.call(/** @type {?} */ (opt_obj), val, index, arr)) {
+ if (goog.array.removeAt(arr, index)) {
+ removedCount++;
+ }
+ }
+ });
+ return removedCount;
+};
+
+
+/**
+ * Returns a new array that is the result of joining the arguments. If arrays
+ * are passed then their items are added, however, if non-arrays are passed they
+ * will be added to the return array as is.
+ *
+ * Note that ArrayLike objects will be added as is, rather than having their
+ * items added.
+ *
+ * goog.array.concat([1, 2], [3, 4]) -> [1, 2, 3, 4]
+ * goog.array.concat(0, [1, 2]) -> [0, 1, 2]
+ * goog.array.concat([1, 2], null) -> [1, 2, null]
+ *
+ * There is bug in all current versions of IE (6, 7 and 8) where arrays created
+ * in an iframe become corrupted soon (not immediately) after the iframe is
+ * destroyed. This is common if loading data via goog.net.IframeIo, for example.
+ * This corruption only affects the concat method which will start throwing
+ * Catastrophic Errors (#-2147418113).
+ *
+ * See http://endoflow.com/scratch/corrupted-arrays.html for a test case.
+ *
+ * Internally goog.array should use this, so that all methods will continue to
+ * work on these broken array objects.
+ *
+ * @param {...*} var_args Items to concatenate. Arrays will have each item
+ * added, while primitives and objects will be added as is.
+ * @return {!Array<?>} The new resultant array.
+ */
+goog.array.concat = function(var_args) {
+ return Array.prototype.concat.apply(Array.prototype, arguments);
+};
+
+
+/**
+ * Returns a new array that contains the contents of all the arrays passed.
+ * @param {...!Array<T>} var_args
+ * @return {!Array<T>}
+ * @template T
+ */
+goog.array.join = function(var_args) {
+ return Array.prototype.concat.apply(Array.prototype, arguments);
+};
+
+
+/**
+ * Converts an object to an array.
+ * @param {IArrayLike<T>|string} object The object to convert to an
+ * array.
+ * @return {!Array<T>} The object converted into an array. If object has a
+ * length property, every property indexed with a non-negative number
+ * less than length will be included in the result. If object does not
+ * have a length property, an empty array will be returned.
+ * @template T
+ */
+goog.array.toArray = function(object) {
+ var length = object.length;
+
+ // If length is not a number the following it false. This case is kept for
+ // backwards compatibility since there are callers that pass objects that are
+ // not array like.
+ if (length > 0) {
+ var rv = new Array(length);
+ for (var i = 0; i < length; i++) {
+ rv[i] = object[i];
+ }
+ return rv;
+ }
+ return [];
+};
+
+
+/**
+ * Does a shallow copy of an array.
+ * @param {IArrayLike<T>|string} arr Array or array-like object to
+ * clone.
+ * @return {!Array<T>} Clone of the input array.
+ * @template T
+ */
+goog.array.clone = goog.array.toArray;
+
+
+/**
+ * Extends an array with another array, element, or "array like" object.
+ * This function operates 'in-place', it does not create a new Array.
+ *
+ * Example:
+ * var a = [];
+ * goog.array.extend(a, [0, 1]);
+ * a; // [0, 1]
+ * goog.array.extend(a, 2);
+ * a; // [0, 1, 2]
+ *
+ * @param {Array<VALUE>} arr1 The array to modify.
+ * @param {...(Array<VALUE>|VALUE)} var_args The elements or arrays of elements
+ * to add to arr1.
+ * @template VALUE
+ */
+goog.array.extend = function(arr1, var_args) {
+ for (var i = 1; i < arguments.length; i++) {
+ var arr2 = arguments[i];
+ if (goog.isArrayLike(arr2)) {
+ var len1 = arr1.length || 0;
+ var len2 = arr2.length || 0;
+ arr1.length = len1 + len2;
+ for (var j = 0; j < len2; j++) {
+ arr1[len1 + j] = arr2[j];
+ }
+ } else {
+ arr1.push(arr2);
+ }
+ }
+};
+
+
+/**
+ * Adds or removes elements from an array. This is a generic version of Array
+ * splice. This means that it might work on other objects similar to arrays,
+ * such as the arguments object.
+ *
+ * @param {IArrayLike<T>} arr The array to modify.
+ * @param {number|undefined} index The index at which to start changing the
+ * array. If not defined, treated as 0.
+ * @param {number} howMany How many elements to remove (0 means no removal. A
+ * value below 0 is treated as zero and so is any other non number. Numbers
+ * are floored).
+ * @param {...T} var_args Optional, additional elements to insert into the
+ * array.
+ * @return {!Array<T>} the removed elements.
+ * @template T
+ */
+goog.array.splice = function(arr, index, howMany, var_args) {
+ goog.asserts.assert(arr.length != null);
+
+ return Array.prototype.splice.apply(arr, goog.array.slice(arguments, 1));
+};
+
+
+/**
+ * Returns a new array from a segment of an array. This is a generic version of
+ * Array slice. This means that it might work on other objects similar to
+ * arrays, such as the arguments object.
+ *
+ * @param {IArrayLike<T>|string} arr The array from
+ * which to copy a segment.
+ * @param {number} start The index of the first element to copy.
+ * @param {number=} opt_end The index after the last element to copy.
+ * @return {!Array<T>} A new array containing the specified segment of the
+ * original array.
+ * @template T
+ */
+goog.array.slice = function(arr, start, opt_end) {
+ goog.asserts.assert(arr.length != null);
+
+ // passing 1 arg to slice is not the same as passing 2 where the second is
+ // null or undefined (in that case the second argument is treated as 0).
+ // we could use slice on the arguments object and then use apply instead of
+ // testing the length
+ if (arguments.length <= 2) {
+ return Array.prototype.slice.call(arr, start);
+ } else {
+ return Array.prototype.slice.call(arr, start, opt_end);
+ }
+};
+
+
+/**
+ * Removes all duplicates from an array (retaining only the first
+ * occurrence of each array element). This function modifies the
+ * array in place and doesn't change the order of the non-duplicate items.
+ *
+ * For objects, duplicates are identified as having the same unique ID as
+ * defined by {@link goog.getUid}.
+ *
+ * Alternatively you can specify a custom hash function that returns a unique
+ * value for each item in the array it should consider unique.
+ *
+ * Runtime: N,
+ * Worstcase space: 2N (no dupes)
+ *
+ * @param {IArrayLike<T>} arr The array from which to remove
+ * duplicates.
+ * @param {Array=} opt_rv An optional array in which to return the results,
+ * instead of performing the removal inplace. If specified, the original
+ * array will remain unchanged.
+ * @param {function(T):string=} opt_hashFn An optional function to use to
+ * apply to every item in the array. This function should return a unique
+ * value for each item in the array it should consider unique.
+ * @template T
+ */
+goog.array.removeDuplicates = function(arr, opt_rv, opt_hashFn) {
+ var returnArray = opt_rv || arr;
+ var defaultHashFn = function(item) {
+ // Prefix each type with a single character representing the type to
+ // prevent conflicting keys (e.g. true and 'true').
+ return goog.isObject(item) ? 'o' + goog.getUid(item) :
+ (typeof item).charAt(0) + item;
+ };
+ var hashFn = opt_hashFn || defaultHashFn;
+
+ var seen = {}, cursorInsert = 0, cursorRead = 0;
+ while (cursorRead < arr.length) {
+ var current = arr[cursorRead++];
+ var key = hashFn(current);
+ if (!Object.prototype.hasOwnProperty.call(seen, key)) {
+ seen[key] = true;
+ returnArray[cursorInsert++] = current;
+ }
+ }
+ returnArray.length = cursorInsert;
+};
+
+
+/**
+ * Searches the specified array for the specified target using the binary
+ * search algorithm. If no opt_compareFn is specified, elements are compared
+ * using <code>goog.array.defaultCompare</code>, which compares the elements
+ * using the built in < and > operators. This will produce the expected
+ * behavior for homogeneous arrays of String(s) and Number(s). The array
+ * specified <b>must</b> be sorted in ascending order (as defined by the
+ * comparison function). If the array is not sorted, results are undefined.
+ * If the array contains multiple instances of the specified target value, any
+ * of these instances may be found.
+ *
+ * Runtime: O(log n)
+ *
+ * @param {IArrayLike<VALUE>} arr The array to be searched.
+ * @param {TARGET} target The sought value.
+ * @param {function(TARGET, VALUE): number=} opt_compareFn Optional comparison
+ * function by which the array is ordered. Should take 2 arguments to
+ * compare, and return a negative number, zero, or a positive number
+ * depending on whether the first argument is less than, equal to, or
+ * greater than the second.
+ * @return {number} Lowest index of the target value if found, otherwise
+ * (-(insertion point) - 1). The insertion point is where the value should
+ * be inserted into arr to preserve the sorted property. Return value >= 0
+ * iff target is found.
+ * @template TARGET, VALUE
+ */
+goog.array.binarySearch = function(arr, target, opt_compareFn) {
+ return goog.array.binarySearch_(
+ arr, opt_compareFn || goog.array.defaultCompare, false /* isEvaluator */,
+ target);
+};
+
+
+/**
+ * Selects an index in the specified array using the binary search algorithm.
+ * The evaluator receives an element and determines whether the desired index
+ * is before, at, or after it. The evaluator must be consistent (formally,
+ * goog.array.map(goog.array.map(arr, evaluator, opt_obj), goog.math.sign)
+ * must be monotonically non-increasing).
+ *
+ * Runtime: O(log n)
+ *
+ * @param {IArrayLike<VALUE>} arr The array to be searched.
+ * @param {function(this:THIS, VALUE, number, ?): number} evaluator
+ * Evaluator function that receives 3 arguments (the element, the index and
+ * the array). Should return a negative number, zero, or a positive number
+ * depending on whether the desired index is before, at, or after the
+ * element passed to it.
+ * @param {THIS=} opt_obj The object to be used as the value of 'this'
+ * within evaluator.
+ * @return {number} Index of the leftmost element matched by the evaluator, if
+ * such exists; otherwise (-(insertion point) - 1). The insertion point is
+ * the index of the first element for which the evaluator returns negative,
+ * or arr.length if no such element exists. The return value is non-negative
+ * iff a match is found.
+ * @template THIS, VALUE
+ */
+goog.array.binarySelect = function(arr, evaluator, opt_obj) {
+ return goog.array.binarySearch_(
+ arr, evaluator, true /* isEvaluator */, undefined /* opt_target */,
+ opt_obj);
+};
+
+
+/**
+ * Implementation of a binary search algorithm which knows how to use both
+ * comparison functions and evaluators. If an evaluator is provided, will call
+ * the evaluator with the given optional data object, conforming to the
+ * interface defined in binarySelect. Otherwise, if a comparison function is
+ * provided, will call the comparison function against the given data object.
+ *
+ * This implementation purposefully does not use goog.bind or goog.partial for
+ * performance reasons.
+ *
+ * Runtime: O(log n)
+ *
+ * @param {IArrayLike<?>} arr The array to be searched.
+ * @param {function(?, ?, ?): number | function(?, ?): number} compareFn
+ * Either an evaluator or a comparison function, as defined by binarySearch
+ * and binarySelect above.
+ * @param {boolean} isEvaluator Whether the function is an evaluator or a
+ * comparison function.
+ * @param {?=} opt_target If the function is a comparison function, then
+ * this is the target to binary search for.
+ * @param {Object=} opt_selfObj If the function is an evaluator, this is an
+ * optional this object for the evaluator.
+ * @return {number} Lowest index of the target value if found, otherwise
+ * (-(insertion point) - 1). The insertion point is where the value should
+ * be inserted into arr to preserve the sorted property. Return value >= 0
+ * iff target is found.
+ * @private
+ */
+goog.array.binarySearch_ = function(
+ arr, compareFn, isEvaluator, opt_target, opt_selfObj) {
+ var left = 0; // inclusive
+ var right = arr.length; // exclusive
+ var found;
+ while (left < right) {
+ var middle = (left + right) >> 1;
+ var compareResult;
+ if (isEvaluator) {
+ compareResult = compareFn.call(opt_selfObj, arr[middle], middle, arr);
+ } else {
+ // NOTE(dimvar): To avoid this cast, we'd have to use function overloading
+ // for the type of binarySearch_, which the type system can't express yet.
+ compareResult = /** @type {function(?, ?): number} */ (compareFn)(
+ opt_target, arr[middle]);
+ }
+ if (compareResult > 0) {
+ left = middle + 1;
+ } else {
+ right = middle;
+ // We are looking for the lowest index so we can't return immediately.
+ found = !compareResult;
+ }
+ }
+ // left is the index if found, or the insertion point otherwise.
+ // ~left is a shorthand for -left - 1.
+ return found ? left : ~left;
+};
+
+
+/**
+ * Sorts the specified array into ascending order. If no opt_compareFn is
+ * specified, elements are compared using
+ * <code>goog.array.defaultCompare</code>, which compares the elements using
+ * the built in < and > operators. This will produce the expected behavior
+ * for homogeneous arrays of String(s) and Number(s), unlike the native sort,
+ * but will give unpredictable results for heterogeneous lists of strings and
+ * numbers with different numbers of digits.
+ *
+ * This sort is not guaranteed to be stable.
+ *
+ * Runtime: Same as <code>Array.prototype.sort</code>
+ *
+ * @param {Array<T>} arr The array to be sorted.
+ * @param {?function(T,T):number=} opt_compareFn Optional comparison
+ * function by which the
+ * array is to be ordered. Should take 2 arguments to compare, and return a
+ * negative number, zero, or a positive number depending on whether the
+ * first argument is less than, equal to, or greater than the second.
+ * @template T
+ */
+goog.array.sort = function(arr, opt_compareFn) {
+ // TODO(arv): Update type annotation since null is not accepted.
+ arr.sort(opt_compareFn || goog.array.defaultCompare);
+};
+
+
+/**
+ * Sorts the specified array into ascending order in a stable way. If no
+ * opt_compareFn is specified, elements are compared using
+ * <code>goog.array.defaultCompare</code>, which compares the elements using
+ * the built in < and > operators. This will produce the expected behavior
+ * for homogeneous arrays of String(s) and Number(s).
+ *
+ * Runtime: Same as <code>Array.prototype.sort</code>, plus an additional
+ * O(n) overhead of copying the array twice.
+ *
+ * @param {Array<T>} arr The array to be sorted.
+ * @param {?function(T, T): number=} opt_compareFn Optional comparison function
+ * by which the array is to be ordered. Should take 2 arguments to compare,
+ * and return a negative number, zero, or a positive number depending on
+ * whether the first argument is less than, equal to, or greater than the
+ * second.
+ * @template T
+ */
+goog.array.stableSort = function(arr, opt_compareFn) {
+ var compArr = new Array(arr.length);
+ for (var i = 0; i < arr.length; i++) {
+ compArr[i] = {index: i, value: arr[i]};
+ }
+ var valueCompareFn = opt_compareFn || goog.array.defaultCompare;
+ function stableCompareFn(obj1, obj2) {
+ return valueCompareFn(obj1.value, obj2.value) || obj1.index - obj2.index;
+ }
+ goog.array.sort(compArr, stableCompareFn);
+ for (var i = 0; i < arr.length; i++) {
+ arr[i] = compArr[i].value;
+ }
+};
+
+
+/**
+ * Sort the specified array into ascending order based on item keys
+ * returned by the specified key function.
+ * If no opt_compareFn is specified, the keys are compared in ascending order
+ * using <code>goog.array.defaultCompare</code>.
+ *
+ * Runtime: O(S(f(n)), where S is runtime of <code>goog.array.sort</code>
+ * and f(n) is runtime of the key function.
+ *
+ * @param {Array<T>} arr The array to be sorted.
+ * @param {function(T): K} keyFn Function taking array element and returning
+ * a key used for sorting this element.
+ * @param {?function(K, K): number=} opt_compareFn Optional comparison function
+ * by which the keys are to be ordered. Should take 2 arguments to compare,
+ * and return a negative number, zero, or a positive number depending on
+ * whether the first argument is less than, equal to, or greater than the
+ * second.
+ * @template T,K
+ */
+goog.array.sortByKey = function(arr, keyFn, opt_compareFn) {
+ var keyCompareFn = opt_compareFn || goog.array.defaultCompare;
+ goog.array.sort(
+ arr, function(a, b) { return keyCompareFn(keyFn(a), keyFn(b)); });
+};
+
+
+/**
+ * Sorts an array of objects by the specified object key and compare
+ * function. If no compare function is provided, the key values are
+ * compared in ascending order using <code>goog.array.defaultCompare</code>.
+ * This won't work for keys that get renamed by the compiler. So use
+ * {'foo': 1, 'bar': 2} rather than {foo: 1, bar: 2}.
+ * @param {Array<Object>} arr An array of objects to sort.
+ * @param {string} key The object key to sort by.
+ * @param {Function=} opt_compareFn The function to use to compare key
+ * values.
+ */
+goog.array.sortObjectsByKey = function(arr, key, opt_compareFn) {
+ goog.array.sortByKey(arr, function(obj) { return obj[key]; }, opt_compareFn);
+};
+
+
+/**
+ * Tells if the array is sorted.
+ * @param {!Array<T>} arr The array.
+ * @param {?function(T,T):number=} opt_compareFn Function to compare the
+ * array elements.
+ * Should take 2 arguments to compare, and return a negative number, zero,
+ * or a positive number depending on whether the first argument is less
+ * than, equal to, or greater than the second.
+ * @param {boolean=} opt_strict If true no equal elements are allowed.
+ * @return {boolean} Whether the array is sorted.
+ * @template T
+ */
+goog.array.isSorted = function(arr, opt_compareFn, opt_strict) {
+ var compare = opt_compareFn || goog.array.defaultCompare;
+ for (var i = 1; i < arr.length; i++) {
+ var compareResult = compare(arr[i - 1], arr[i]);
+ if (compareResult > 0 || compareResult == 0 && opt_strict) {
+ return false;
+ }
+ }
+ return true;
+};
+
+
+/**
+ * Compares two arrays for equality. Two arrays are considered equal if they
+ * have the same length and their corresponding elements are equal according to
+ * the comparison function.
+ *
+ * @param {IArrayLike<?>} arr1 The first array to compare.
+ * @param {IArrayLike<?>} arr2 The second array to compare.
+ * @param {Function=} opt_equalsFn Optional comparison function.
+ * Should take 2 arguments to compare, and return true if the arguments
+ * are equal. Defaults to {@link goog.array.defaultCompareEquality} which
+ * compares the elements using the built-in '===' operator.
+ * @return {boolean} Whether the two arrays are equal.
+ */
+goog.array.equals = function(arr1, arr2, opt_equalsFn) {
+ if (!goog.isArrayLike(arr1) || !goog.isArrayLike(arr2) ||
+ arr1.length != arr2.length) {
+ return false;
+ }
+ var l = arr1.length;
+ var equalsFn = opt_equalsFn || goog.array.defaultCompareEquality;
+ for (var i = 0; i < l; i++) {
+ if (!equalsFn(arr1[i], arr2[i])) {
+ return false;
+ }
+ }
+ return true;
+};
+
+
+/**
+ * 3-way array compare function.
+ * @param {!IArrayLike<VALUE>} arr1 The first array to
+ * compare.
+ * @param {!IArrayLike<VALUE>} arr2 The second array to
+ * compare.
+ * @param {function(VALUE, VALUE): number=} opt_compareFn Optional comparison
+ * function by which the array is to be ordered. Should take 2 arguments to
+ * compare, and return a negative number, zero, or a positive number
+ * depending on whether the first argument is less than, equal to, or
+ * greater than the second.
+ * @return {number} Negative number, zero, or a positive number depending on
+ * whether the first argument is less than, equal to, or greater than the
+ * second.
+ * @template VALUE
+ */
+goog.array.compare3 = function(arr1, arr2, opt_compareFn) {
+ var compare = opt_compareFn || goog.array.defaultCompare;
+ var l = Math.min(arr1.length, arr2.length);
+ for (var i = 0; i < l; i++) {
+ var result = compare(arr1[i], arr2[i]);
+ if (result != 0) {
+ return result;
+ }
+ }
+ return goog.array.defaultCompare(arr1.length, arr2.length);
+};
+
+
+/**
+ * Compares its two arguments for order, using the built in < and >
+ * operators.
+ * @param {VALUE} a The first object to be compared.
+ * @param {VALUE} b The second object to be compared.
+ * @return {number} A negative number, zero, or a positive number as the first
+ * argument is less than, equal to, or greater than the second,
+ * respectively.
+ * @template VALUE
+ */
+goog.array.defaultCompare = function(a, b) {
+ return a > b ? 1 : a < b ? -1 : 0;
+};
+
+
+/**
+ * Compares its two arguments for inverse order, using the built in < and >
+ * operators.
+ * @param {VALUE} a The first object to be compared.
+ * @param {VALUE} b The second object to be compared.
+ * @return {number} A negative number, zero, or a positive number as the first
+ * argument is greater than, equal to, or less than the second,
+ * respectively.
+ * @template VALUE
+ */
+goog.array.inverseDefaultCompare = function(a, b) {
+ return -goog.array.defaultCompare(a, b);
+};
+
+
+/**
+ * Compares its two arguments for equality, using the built in === operator.
+ * @param {*} a The first object to compare.
+ * @param {*} b The second object to compare.
+ * @return {boolean} True if the two arguments are equal, false otherwise.
+ */
+goog.array.defaultCompareEquality = function(a, b) {
+ return a === b;
+};
+
+
+/**
+ * Inserts a value into a sorted array. The array is not modified if the
+ * value is already present.
+ * @param {IArrayLike<VALUE>} array The array to modify.
+ * @param {VALUE} value The object to insert.
+ * @param {function(VALUE, VALUE): number=} opt_compareFn Optional comparison
+ * function by which the array is ordered. Should take 2 arguments to
+ * compare, and return a negative number, zero, or a positive number
+ * depending on whether the first argument is less than, equal to, or
+ * greater than the second.
+ * @return {boolean} True if an element was inserted.
+ * @template VALUE
+ */
+goog.array.binaryInsert = function(array, value, opt_compareFn) {
+ var index = goog.array.binarySearch(array, value, opt_compareFn);
+ if (index < 0) {
+ goog.array.insertAt(array, value, -(index + 1));
+ return true;
+ }
+ return false;
+};
+
+
+/**
+ * Removes a value from a sorted array.
+ * @param {!IArrayLike<VALUE>} array The array to modify.
+ * @param {VALUE} value The object to remove.
+ * @param {function(VALUE, VALUE): number=} opt_compareFn Optional comparison
+ * function by which the array is ordered. Should take 2 arguments to
+ * compare, and return a negative number, zero, or a positive number
+ * depending on whether the first argument is less than, equal to, or
+ * greater than the second.
+ * @return {boolean} True if an element was removed.
+ * @template VALUE
+ */
+goog.array.binaryRemove = function(array, value, opt_compareFn) {
+ var index = goog.array.binarySearch(array, value, opt_compareFn);
+ return (index >= 0) ? goog.array.removeAt(array, index) : false;
+};
+
+
+/**
+ * Splits an array into disjoint buckets according to a splitting function.
+ * @param {Array<T>} array The array.
+ * @param {function(this:S, T,number,Array<T>):?} sorter Function to call for
+ * every element. This takes 3 arguments (the element, the index and the
+ * array) and must return a valid object key (a string, number, etc), or
+ * undefined, if that object should not be placed in a bucket.
+ * @param {S=} opt_obj The object to be used as the value of 'this' within
+ * sorter.
+ * @return {!Object} An object, with keys being all of the unique return values
+ * of sorter, and values being arrays containing the items for
+ * which the splitter returned that key.
+ * @template T,S
+ */
+goog.array.bucket = function(array, sorter, opt_obj) {
+ var buckets = {};
+
+ for (var i = 0; i < array.length; i++) {
+ var value = array[i];
+ var key = sorter.call(/** @type {?} */ (opt_obj), value, i, array);
+ if (goog.isDef(key)) {
+ // Push the value to the right bucket, creating it if necessary.
+ var bucket = buckets[key] || (buckets[key] = []);
+ bucket.push(value);
+ }
+ }
+
+ return buckets;
+};
+
+
+/**
+ * Creates a new object built from the provided array and the key-generation
+ * function.
+ * @param {IArrayLike<T>} arr Array or array like object over
+ * which to iterate whose elements will be the values in the new object.
+ * @param {?function(this:S, T, number, ?) : string} keyFunc The function to
+ * call for every element. This function takes 3 arguments (the element, the
+ * index and the array) and should return a string that will be used as the
+ * key for the element in the new object. If the function returns the same
+ * key for more than one element, the value for that key is
+ * implementation-defined.
+ * @param {S=} opt_obj The object to be used as the value of 'this'
+ * within keyFunc.
+ * @return {!Object<T>} The new object.
+ * @template T,S
+ */
+goog.array.toObject = function(arr, keyFunc, opt_obj) {
+ var ret = {};
+ goog.array.forEach(arr, function(element, index) {
+ ret[keyFunc.call(/** @type {?} */ (opt_obj), element, index, arr)] =
+ element;
+ });
+ return ret;
+};
+
+
+/**
+ * Creates a range of numbers in an arithmetic progression.
+ *
+ * Range takes 1, 2, or 3 arguments:
+ * <pre>
+ * range(5) is the same as range(0, 5, 1) and produces [0, 1, 2, 3, 4]
+ * range(2, 5) is the same as range(2, 5, 1) and produces [2, 3, 4]
+ * range(-2, -5, -1) produces [-2, -3, -4]
+ * range(-2, -5, 1) produces [], since stepping by 1 wouldn't ever reach -5.
+ * </pre>
+ *
+ * @param {number} startOrEnd The starting value of the range if an end argument
+ * is provided. Otherwise, the start value is 0, and this is the end value.
+ * @param {number=} opt_end The optional end value of the range.
+ * @param {number=} opt_step The step size between range values. Defaults to 1
+ * if opt_step is undefined or 0.
+ * @return {!Array<number>} An array of numbers for the requested range. May be
+ * an empty array if adding the step would not converge toward the end
+ * value.
+ */
+goog.array.range = function(startOrEnd, opt_end, opt_step) {
+ var array = [];
+ var start = 0;
+ var end = startOrEnd;
+ var step = opt_step || 1;
+ if (opt_end !== undefined) {
+ start = startOrEnd;
+ end = opt_end;
+ }
+
+ if (step * (end - start) < 0) {
+ // Sign mismatch: start + step will never reach the end value.
+ return [];
+ }
+
+ if (step > 0) {
+ for (var i = start; i < end; i += step) {
+ array.push(i);
+ }
+ } else {
+ for (var i = start; i > end; i += step) {
+ array.push(i);
+ }
+ }
+ return array;
+};
+
+
+/**
+ * Returns an array consisting of the given value repeated N times.
+ *
+ * @param {VALUE} value The value to repeat.
+ * @param {number} n The repeat count.
+ * @return {!Array<VALUE>} An array with the repeated value.
+ * @template VALUE
+ */
+goog.array.repeat = function(value, n) {
+ var array = [];
+ for (var i = 0; i < n; i++) {
+ array[i] = value;
+ }
+ return array;
+};
+
+
+/**
+ * Returns an array consisting of every argument with all arrays
+ * expanded in-place recursively.
+ *
+ * @param {...*} var_args The values to flatten.
+ * @return {!Array<?>} An array containing the flattened values.
+ */
+goog.array.flatten = function(var_args) {
+ var CHUNK_SIZE = 8192;
+
+ var result = [];
+ for (var i = 0; i < arguments.length; i++) {
+ var element = arguments[i];
+ if (goog.isArray(element)) {
+ for (var c = 0; c < element.length; c += CHUNK_SIZE) {
+ var chunk = goog.array.slice(element, c, c + CHUNK_SIZE);
+ var recurseResult = goog.array.flatten.apply(null, chunk);
+ for (var r = 0; r < recurseResult.length; r++) {
+ result.push(recurseResult[r]);
+ }
+ }
+ } else {
+ result.push(element);
+ }
+ }
+ return result;
+};
+
+
+/**
+ * Rotates an array in-place. After calling this method, the element at
+ * index i will be the element previously at index (i - n) %
+ * array.length, for all values of i between 0 and array.length - 1,
+ * inclusive.
+ *
+ * For example, suppose list comprises [t, a, n, k, s]. After invoking
+ * rotate(array, 1) (or rotate(array, -4)), array will comprise [s, t, a, n, k].
+ *
+ * @param {!Array<T>} array The array to rotate.
+ * @param {number} n The amount to rotate.
+ * @return {!Array<T>} The array.
+ * @template T
+ */
+goog.array.rotate = function(array, n) {
+ goog.asserts.assert(array.length != null);
+
+ if (array.length) {
+ n %= array.length;
+ if (n > 0) {
+ Array.prototype.unshift.apply(array, array.splice(-n, n));
+ } else if (n < 0) {
+ Array.prototype.push.apply(array, array.splice(0, -n));
+ }
+ }
+ return array;
+};
+
+
+/**
+ * Moves one item of an array to a new position keeping the order of the rest
+ * of the items. Example use case: keeping a list of JavaScript objects
+ * synchronized with the corresponding list of DOM elements after one of the
+ * elements has been dragged to a new position.
+ * @param {!IArrayLike<?>} arr The array to modify.
+ * @param {number} fromIndex Index of the item to move between 0 and
+ * {@code arr.length - 1}.
+ * @param {number} toIndex Target index between 0 and {@code arr.length - 1}.
+ */
+goog.array.moveItem = function(arr, fromIndex, toIndex) {
+ goog.asserts.assert(fromIndex >= 0 && fromIndex < arr.length);
+ goog.asserts.assert(toIndex >= 0 && toIndex < arr.length);
+ // Remove 1 item at fromIndex.
+ var removedItems = Array.prototype.splice.call(arr, fromIndex, 1);
+ // Insert the removed item at toIndex.
+ Array.prototype.splice.call(arr, toIndex, 0, removedItems[0]);
+ // We don't use goog.array.insertAt and goog.array.removeAt, because they're
+ // significantly slower than splice.
+};
+
+
+/**
+ * Creates a new array for which the element at position i is an array of the
+ * ith element of the provided arrays. The returned array will only be as long
+ * as the shortest array provided; additional values are ignored. For example,
+ * the result of zipping [1, 2] and [3, 4, 5] is [[1,3], [2, 4]].
+ *
+ * This is similar to the zip() function in Python. See {@link
+ * http://docs.python.org/library/functions.html#zip}
+ *
+ * @param {...!IArrayLike<?>} var_args Arrays to be combined.
+ * @return {!Array<!Array<?>>} A new array of arrays created from
+ * provided arrays.
+ */
+goog.array.zip = function(var_args) {
+ if (!arguments.length) {
+ return [];
+ }
+ var result = [];
+ var minLen = arguments[0].length;
+ for (var i = 1; i < arguments.length; i++) {
+ if (arguments[i].length < minLen) {
+ minLen = arguments[i].length;
+ }
+ }
+ for (var i = 0; i < minLen; i++) {
+ var value = [];
+ for (var j = 0; j < arguments.length; j++) {
+ value.push(arguments[j][i]);
+ }
+ result.push(value);
+ }
+ return result;
+};
+
+
+/**
+ * Shuffles the values in the specified array using the Fisher-Yates in-place
+ * shuffle (also known as the Knuth Shuffle). By default, calls Math.random()
+ * and so resets the state of that random number generator. Similarly, may reset
+ * the state of the any other specified random number generator.
+ *
+ * Runtime: O(n)
+ *
+ * @param {!Array<?>} arr The array to be shuffled.
+ * @param {function():number=} opt_randFn Optional random function to use for
+ * shuffling.
+ * Takes no arguments, and returns a random number on the interval [0, 1).
+ * Defaults to Math.random() using JavaScript's built-in Math library.
+ */
+goog.array.shuffle = function(arr, opt_randFn) {
+ var randFn = opt_randFn || Math.random;
+
+ for (var i = arr.length - 1; i > 0; i--) {
+ // Choose a random array index in [0, i] (inclusive with i).
+ var j = Math.floor(randFn() * (i + 1));
+
+ var tmp = arr[i];
+ arr[i] = arr[j];
+ arr[j] = tmp;
+ }
+};
+
+
+/**
+ * Returns a new array of elements from arr, based on the indexes of elements
+ * provided by index_arr. For example, the result of index copying
+ * ['a', 'b', 'c'] with index_arr [1,0,0,2] is ['b', 'a', 'a', 'c'].
+ *
+ * @param {!Array<T>} arr The array to get a indexed copy from.
+ * @param {!Array<number>} index_arr An array of indexes to get from arr.
+ * @return {!Array<T>} A new array of elements from arr in index_arr order.
+ * @template T
+ */
+goog.array.copyByIndex = function(arr, index_arr) {
+ var result = [];
+ goog.array.forEach(index_arr, function(index) { result.push(arr[index]); });
+ return result;
+};
+
+
+/**
+ * Maps each element of the input array into zero or more elements of the output
+ * array.
+ *
+ * @param {!IArrayLike<VALUE>|string} arr Array or array like object
+ * over which to iterate.
+ * @param {function(this:THIS, VALUE, number, ?): !Array<RESULT>} f The function
+ * to call for every element. This function takes 3 arguments (the element,
+ * the index and the array) and should return an array. The result will be
+ * used to extend a new array.
+ * @param {THIS=} opt_obj The object to be used as the value of 'this' within f.
+ * @return {!Array<RESULT>} a new array with the concatenation of all arrays
+ * returned from f.
+ * @template THIS, VALUE, RESULT
+ */
+goog.array.concatMap = function(arr, f, opt_obj) {
+ return goog.array.concat.apply([], goog.array.map(arr, f, opt_obj));
+};

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