src/weakmap.js

// Copyright 2011 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
//     * Redistributions of source code must retain the above copyright
//       notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
//       copyright notice, this list of conditions and the following
//       disclaimer in the documentation and/or other materials provided
//       with the distribution.
//     * Neither the name of Google Inc. nor the names of its
//       contributors may be used to endorse or promote products derived
//       from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// This file relies on the fact that the following declaration has been made
// in runtime.js:
// const $Object = global.Object;
const $WeakMap = global.WeakMap;

// -------------------------------------------------------------------

function WeakMapConstructor() {
  if (%_IsConstructCall()) {
    %WeakMapInitialize(this);
  } else {
    return new $WeakMap();
  }
}


function WeakMapGet(key) {
  if (!IS_SPEC_OBJECT(key)) {
    throw %MakeTypeError('invalid_weakmap_key', [this, key]);
  }
  return %WeakMapGet(this, key);
}


function WeakMapSet(key, value) {
  if (!IS_SPEC_OBJECT(key)) {
    throw %MakeTypeError('invalid_weakmap_key', [this, key]);
  }
  return %WeakMapSet(this, key, value);
}


function WeakMapHas(key) {
  if (!IS_SPEC_OBJECT(key)) {
    throw %MakeTypeError('invalid_weakmap_key', [this, key]);
  }
  return !IS_UNDEFINED(%WeakMapGet(this, key));
}


function WeakMapDelete(key) {
  if (!IS_SPEC_OBJECT(key)) {
    throw %MakeTypeError('invalid_weakmap_key', [this, key]);
  }
  if (!IS_UNDEFINED(%WeakMapGet(this, key))) {
    %WeakMapSet(this, key, void 0);
    return true;
  } else {
    return false;
  }
}

// -------------------------------------------------------------------

(function () {
  %CheckIsBootstrapping();
  // Set up the WeakMap constructor function.
  %SetCode($WeakMap, WeakMapConstructor);

  // Set up the constructor property on the WeakMap prototype object.
  %SetProperty($WeakMap.prototype, "constructor", $WeakMap, DONT_ENUM);

  // Set up the non-enumerable functions on the WeakMap prototype object.
  InstallFunctionsOnHiddenPrototype($WeakMap.prototype, DONT_ENUM, $Array(
    "get", WeakMapGet,
    "set", WeakMapSet,
    "has", WeakMapHas,
    "delete", WeakMapDelete
  ));
})();