builtins/ObjectConstructor.js

   1 /*
   2  * Copyright (C) 2015 Jordan Harband. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 function assign(target/*[*/, /*...*/sources/*] */) {
  27     "use strict";
  28
  29     if (target == null)
  30         throw new @TypeError("can't convert " + target + " to object");
  31
  32     var objTarget = @Object(target);
  33     var s, nextSource, from, i, keys, nextKey, desc;
  34     for (s = 1; s < arguments.length; ++s) {
  35         nextSource = arguments[s];
  36         if (nextSource != null) {
  37             from = @Object(nextSource);
  38             // TODO: replace @objectKeys + @objectGetOwnPropertySymbols with single @OwnPropertyKeys c++ operation
  39             keys = @objectKeys(from);
  40             for (i = 0; i < keys.length; ++i) {
  41                 nextKey = keys[i];
  42                 desc = @objectGetOwnPropertyDescriptor(from, nextKey);
  43                 if (typeof desc !== "undefined" && desc.enumerable) {
  44                     objTarget[nextKey] = from[nextKey];
  45                 }
  46             }
  47             keys = @objectGetOwnPropertySymbols(from);
  48             for (i = 0; i < keys.length; ++i) {
  49                 nextKey = keys[i];
  50                 desc = @objectGetOwnPropertyDescriptor(from, nextKey);
  51                 if (typeof desc !== "undefined" && desc.enumerable) {
  52                     objTarget[nextKey] = from[nextKey];
  53                 }
  54             }
  55         }
  56     }
  57     return objTarget;
  58 }