v8/src/generator.js
2014-09-17 12:27:16 +00:00

88 lines
3.0 KiB
JavaScript

// Copyright 2013 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
"use strict";
// This file relies on the fact that the following declarations have been made
// in runtime.js:
// var $Function = global.Function;
// ----------------------------------------------------------------------------
// Generator functions and objects are specified by ES6, sections 15.19.3 and
// 15.19.4.
function GeneratorObjectNext(value) {
if (!IS_GENERATOR(this)) {
throw MakeTypeError('incompatible_method_receiver',
['[Generator].prototype.next', this]);
}
if (DEBUG_IS_ACTIVE) %DebugPrepareStepInIfStepping(this);
return %_GeneratorNext(this, value);
}
function GeneratorObjectThrow(exn) {
if (!IS_GENERATOR(this)) {
throw MakeTypeError('incompatible_method_receiver',
['[Generator].prototype.throw', this]);
}
return %_GeneratorThrow(this, exn);
}
function GeneratorObjectIterator() {
return this;
}
function GeneratorFunctionPrototypeConstructor(x) {
if (%_IsConstructCall()) {
throw MakeTypeError('not_constructor', ['GeneratorFunctionPrototype']);
}
}
function GeneratorFunctionConstructor(arg1) { // length == 1
var source = NewFunctionString(arguments, 'function*');
var global_proxy = %GlobalProxy(global);
// Compile the string in the constructor and not a helper so that errors
// appear to come from here.
var f = %CompileString(source, true);
if (!IS_FUNCTION(f)) return f;
f = %_CallFunction(global_proxy, f);
%FunctionMarkNameShouldPrintAsAnonymous(f);
return f;
}
function SetUpGenerators() {
%CheckIsBootstrapping();
// Both Runtime_GeneratorNext and Runtime_GeneratorThrow are supported by
// neither Crankshaft nor TurboFan, disable optimization of wrappers here.
%NeverOptimizeFunction(GeneratorObjectNext);
%NeverOptimizeFunction(GeneratorObjectThrow);
// Set up non-enumerable functions on the generator prototype object.
var GeneratorObjectPrototype = GeneratorFunctionPrototype.prototype;
InstallFunctions(GeneratorObjectPrototype,
DONT_ENUM | DONT_DELETE | READ_ONLY,
["next", GeneratorObjectNext,
"throw", GeneratorObjectThrow]);
%FunctionSetName(GeneratorObjectIterator, '[Symbol.iterator]');
%AddNamedProperty(GeneratorObjectPrototype, symbolIterator,
GeneratorObjectIterator, DONT_ENUM | DONT_DELETE | READ_ONLY);
%AddNamedProperty(GeneratorObjectPrototype, "constructor",
GeneratorFunctionPrototype, DONT_ENUM | DONT_DELETE | READ_ONLY);
%InternalSetPrototype(GeneratorFunctionPrototype, $Function.prototype);
%SetCode(GeneratorFunctionPrototype, GeneratorFunctionPrototypeConstructor);
%AddNamedProperty(GeneratorFunctionPrototype, "constructor",
GeneratorFunction, DONT_ENUM | DONT_DELETE | READ_ONLY);
%InternalSetPrototype(GeneratorFunction, $Function);
%SetCode(GeneratorFunction, GeneratorFunctionConstructor);
}
SetUpGenerators();