src/generator.js

// Copyright 2013 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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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"use strict";

// This file relies on the fact that the following declarations have been made
// in runtime.js:
// var $Function = global.Function;

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


// TODO(wingo): Give link to specification. For now, the following diagram is
// the spec:
// http://wiki.ecmascript.org/lib/exe/fetch.php?cache=cache&media=harmony:es6_generator_object_model_3-29-13.png

function GeneratorObjectNext() {
  if (!IS_GENERATOR(this)) {
    throw MakeTypeError('incompatible_method_receiver',
                        ['[Generator].prototype.next', this]);
  }

  return %_GeneratorSend(this, void 0);
}

function GeneratorObjectSend(value) {
  if (!IS_GENERATOR(this)) {
    throw MakeTypeError('incompatible_method_receiver',
                        ['[Generator].prototype.send', this]);
  }

  return %_GeneratorSend(this, value);
}

function GeneratorObjectThrow(exn) {
  if (!IS_GENERATOR(this)) {
    throw MakeTypeError('incompatible_method_receiver',
                        ['[Generator].prototype.throw', this]);
  }

  return %_GeneratorThrow(this, exn);
}

function SetUpGenerators() {
  %CheckIsBootstrapping();
  var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
  InstallFunctions(GeneratorObjectPrototype,
                   DONT_ENUM | DONT_DELETE | READ_ONLY,
                   ["next", GeneratorObjectNext,
                    "send", GeneratorObjectSend,
                    "throw", GeneratorObjectThrow]);
  %SetProperty(GeneratorObjectPrototype, "constructor",
               GeneratorFunctionPrototype, DONT_ENUM | DONT_DELETE | READ_ONLY);
  %SetPrototype(GeneratorFunctionPrototype, $Function.prototype);
  %SetProperty(GeneratorFunctionPrototype, "constructor",
               GeneratorFunction, DONT_ENUM | DONT_DELETE | READ_ONLY);
  %SetPrototype(GeneratorFunction, $Function);
}

SetUpGenerators();