108 lines
2.8 KiB
JavaScript
108 lines
2.8 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Copyright (c) 2013-present, Facebook, Inc.
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* This source code is licensed under the BSD-style license found in the
|
||
|
|
* LICENSE file in the root directory of this source tree. An additional grant
|
||
|
|
* of patent rights can be found in the PATENTS file in the same directory.
|
||
|
|
*
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
var aStackPool = [];
|
||
|
|
var bStackPool = [];
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Checks if two values are equal. Values may be primitives, arrays, or objects.
|
||
|
|
* Returns true if both arguments have the same keys and values.
|
||
|
|
*
|
||
|
|
* @see http://underscorejs.org
|
||
|
|
* @copyright 2009-2013 Jeremy Ashkenas, DocumentCloud Inc.
|
||
|
|
* @license MIT
|
||
|
|
*/
|
||
|
|
function areEqual(a, b) {
|
||
|
|
var aStack = aStackPool.length ? aStackPool.pop() : [];
|
||
|
|
var bStack = bStackPool.length ? bStackPool.pop() : [];
|
||
|
|
var result = eq(a, b, aStack, bStack);
|
||
|
|
aStack.length = 0;
|
||
|
|
bStack.length = 0;
|
||
|
|
aStackPool.push(aStack);
|
||
|
|
bStackPool.push(bStack);
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
|
||
|
|
function eq(a, b, aStack, bStack) {
|
||
|
|
if (a === b) {
|
||
|
|
// Identical objects are equal. `0 === -0`, but they aren't identical.
|
||
|
|
return a !== 0 || 1 / a == 1 / b;
|
||
|
|
}
|
||
|
|
if (a == null || b == null) {
|
||
|
|
// a or b can be `null` or `undefined`
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (typeof a != 'object' || typeof b != 'object') {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
var objToStr = Object.prototype.toString;
|
||
|
|
var className = objToStr.call(a);
|
||
|
|
if (className != objToStr.call(b)) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
switch (className) {
|
||
|
|
case '[object String]':
|
||
|
|
return a == String(b);
|
||
|
|
case '[object Number]':
|
||
|
|
return isNaN(a) || isNaN(b) ? false : a == Number(b);
|
||
|
|
case '[object Date]':
|
||
|
|
case '[object Boolean]':
|
||
|
|
return +a == +b;
|
||
|
|
case '[object RegExp]':
|
||
|
|
return a.source == b.source && a.global == b.global && a.multiline == b.multiline && a.ignoreCase == b.ignoreCase;
|
||
|
|
}
|
||
|
|
// Assume equality for cyclic structures.
|
||
|
|
var length = aStack.length;
|
||
|
|
while (length--) {
|
||
|
|
if (aStack[length] == a) {
|
||
|
|
return bStack[length] == b;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
aStack.push(a);
|
||
|
|
bStack.push(b);
|
||
|
|
var size = 0;
|
||
|
|
// Recursively compare objects and arrays.
|
||
|
|
if (className === '[object Array]') {
|
||
|
|
size = a.length;
|
||
|
|
if (size !== b.length) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
// Deep compare the contents, ignoring non-numeric properties.
|
||
|
|
while (size--) {
|
||
|
|
if (!eq(a[size], b[size], aStack, bStack)) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
if (a.constructor !== b.constructor) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
if (a.hasOwnProperty('valueOf') && b.hasOwnProperty('valueOf')) {
|
||
|
|
return a.valueOf() == b.valueOf();
|
||
|
|
}
|
||
|
|
var keys = Object.keys(a);
|
||
|
|
if (keys.length != Object.keys(b).length) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
for (var i = 0; i < keys.length; i++) {
|
||
|
|
if (!eq(a[keys[i]], b[keys[i]], aStack, bStack)) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
aStack.pop();
|
||
|
|
bStack.pop();
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = areEqual;
|