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// Copyright 2014 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 declaration has been made
// in runtime.js:
// var $String = global.String;
var stringIteratorIteratedStringSymbol =
GLOBAL_PRIVATE("StringIterator#iteratedString");
var stringIteratorNextIndexSymbol = GLOBAL_PRIVATE("StringIterator#next");
function StringIterator() {}
// 21.1.5.1 CreateStringIterator Abstract Operation
function CreateStringIterator(string) {
var s = TO_STRING_INLINE(string);
var iterator = new StringIterator;
SET_PRIVATE(iterator, stringIteratorIteratedStringSymbol, s);
SET_PRIVATE(iterator, stringIteratorNextIndexSymbol, 0);
return iterator;
}
// 21.1.5.2.2 %StringIteratorPrototype%[@@iterator]
function StringIteratorIterator() {
return this;
}
// 21.1.5.2.1 %StringIteratorPrototype%.next( )
function StringIteratorNext() {
var iterator = ToObject(this);
if (!HAS_DEFINED_PRIVATE(iterator, stringIteratorNextIndexSymbol)) {
throw MakeTypeError('incompatible_method_receiver',
['String Iterator.prototype.next']);
}
var s = GET_PRIVATE(iterator, stringIteratorIteratedStringSymbol);
if (IS_UNDEFINED(s)) {
return CreateIteratorResultObject(UNDEFINED, true);
}
var position = GET_PRIVATE(iterator, stringIteratorNextIndexSymbol);
var length = TO_UINT32(s.length);
if (position >= length) {
SET_PRIVATE(iterator, stringIteratorIteratedStringSymbol,
UNDEFINED);
return CreateIteratorResultObject(UNDEFINED, true);
}
var first = %_StringCharCodeAt(s, position);
var resultString = %_StringCharFromCode(first);
position++;
if (first >= 0xD800 && first <= 0xDBFF && position < length) {
var second = %_StringCharCodeAt(s, position);
if (second >= 0xDC00 && second <= 0xDFFF) {
resultString += %_StringCharFromCode(second);
position++;
}
}
SET_PRIVATE(iterator, stringIteratorNextIndexSymbol, position);
return CreateIteratorResultObject(resultString, false);
}
function SetUpStringIterator() {
%CheckIsBootstrapping();
%FunctionSetPrototype(StringIterator, new $Object());
%FunctionSetInstanceClassName(StringIterator, 'String Iterator');
InstallFunctions(StringIterator.prototype, DONT_ENUM, $Array(
'next', StringIteratorNext
));
%FunctionSetName(StringIteratorIterator, '[Symbol.iterator]');
%AddNamedProperty(StringIterator.prototype, symbolIterator,
StringIteratorIterator, DONT_ENUM);
%AddNamedProperty(StringIterator.prototype, symbolToStringTag,
"String Iterator", READ_ONLY | DONT_ENUM);
}
SetUpStringIterator();
// 21.1.3.27 String.prototype [ @@iterator ]( )
function StringPrototypeIterator() {
return CreateStringIterator(this);
}
function ExtendStringPrototypeWithIterator() {
%CheckIsBootstrapping();
%FunctionSetName(StringPrototypeIterator, '[Symbol.iterator]');
%AddNamedProperty($String.prototype, symbolIterator,
StringPrototypeIterator, DONT_ENUM);
}
ExtendStringPrototypeWithIterator();
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