Tools/IonGraph/src/dequal.ts

/*
 * Taken from the MIT-licensed dequal library by lukeed:
 * https://github.com/lukeed/dequal/blob/81075b120e86b5c8703c4c7ad0c541651b0df87f/src/lite.js
 *
 *
 * The MIT License (MIT)
 *
 * Copyright (c) Luke Edwards <luke.edwards05@gmail.com> (lukeed.com)
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

var has = Object.prototype.hasOwnProperty;

export function dequal(foo: any, bar: any): boolean {
  var ctor, len;
  if (foo === bar) return true;

  if (foo && bar && (ctor = foo.constructor) === bar.constructor) {
    if (ctor === Date) return foo.getTime() === bar.getTime();
    if (ctor === RegExp) return foo.toString() === bar.toString();

    if (ctor === Array) {
      if ((len = foo.length) === bar.length) {
        while (len-- && dequal(foo[len], bar[len]));
      }
      return len === -1;
    }

    if (!ctor || typeof foo === 'object') {
      len = 0;
      for (ctor in foo) {
        if (has.call(foo, ctor) && ++len && !has.call(bar, ctor)) return false;
        if (!(ctor in bar) || !dequal(foo[ctor], bar[ctor])) return false;
      }
      return Object.keys(bar).length === len;
    }
  }

  return foo !== foo && bar !== bar;
}