| // 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 $Array = global.Array; |
| |
| // ------------------------------------------------------------------- |
| |
| // ES6 draft 01-20-14, section 21.1.3.13 |
| function StringRepeat(count) { |
| CHECK_OBJECT_COERCIBLE(this, "String.prototype.repeat"); |
| |
| var s = TO_STRING_INLINE(this); |
| var n = ToInteger(count); |
| // The maximum string length is stored in a smi, so a longer repeat |
| // must result in a range error. |
| if (n < 0 || n > %_MaxSmi()) { |
| throw MakeRangeError("invalid_count_value", []); |
| } |
| |
| var r = ""; |
| while (true) { |
| if (n & 1) r += s; |
| n >>= 1; |
| if (n === 0) return r; |
| s += s; |
| } |
| } |
| |
| |
| // ES6 draft 04-05-14, section 21.1.3.18 |
| function StringStartsWith(searchString /* position */) { // length == 1 |
| CHECK_OBJECT_COERCIBLE(this, "String.prototype.startsWith"); |
| |
| var s = TO_STRING_INLINE(this); |
| |
| if (IS_REGEXP(searchString)) { |
| throw MakeTypeError("first_argument_not_regexp", |
| ["String.prototype.startsWith"]); |
| } |
| |
| var ss = TO_STRING_INLINE(searchString); |
| var pos = 0; |
| if (%_ArgumentsLength() > 1) { |
| pos = %_Arguments(1); // position |
| pos = ToInteger(pos); |
| } |
| |
| var s_len = s.length; |
| var start = MathMin(MathMax(pos, 0), s_len); |
| var ss_len = ss.length; |
| if (ss_len + start > s_len) { |
| return false; |
| } |
| |
| return %StringIndexOf(s, ss, start) === start; |
| } |
| |
| |
| // ES6 draft 04-05-14, section 21.1.3.7 |
| function StringEndsWith(searchString /* position */) { // length == 1 |
| CHECK_OBJECT_COERCIBLE(this, "String.prototype.endsWith"); |
| |
| var s = TO_STRING_INLINE(this); |
| |
| if (IS_REGEXP(searchString)) { |
| throw MakeTypeError("first_argument_not_regexp", |
| ["String.prototype.endsWith"]); |
| } |
| |
| var ss = TO_STRING_INLINE(searchString); |
| var s_len = s.length; |
| var pos = s_len; |
| if (%_ArgumentsLength() > 1) { |
| var arg = %_Arguments(1); // position |
| if (!IS_UNDEFINED(arg)) { |
| pos = ToInteger(arg); |
| } |
| } |
| |
| var end = MathMin(MathMax(pos, 0), s_len); |
| var ss_len = ss.length; |
| var start = end - ss_len; |
| if (start < 0) { |
| return false; |
| } |
| |
| return %StringLastIndexOf(s, ss, start) === start; |
| } |
| |
| |
| // ES6 draft 04-05-14, section 21.1.3.6 |
| function StringContains(searchString /* position */) { // length == 1 |
| CHECK_OBJECT_COERCIBLE(this, "String.prototype.contains"); |
| |
| var s = TO_STRING_INLINE(this); |
| |
| if (IS_REGEXP(searchString)) { |
| throw MakeTypeError("first_argument_not_regexp", |
| ["String.prototype.contains"]); |
| } |
| |
| var ss = TO_STRING_INLINE(searchString); |
| var pos = 0; |
| if (%_ArgumentsLength() > 1) { |
| pos = %_Arguments(1); // position |
| pos = ToInteger(pos); |
| } |
| |
| var s_len = s.length; |
| var start = MathMin(MathMax(pos, 0), s_len); |
| var ss_len = ss.length; |
| if (ss_len + start > s_len) { |
| return false; |
| } |
| |
| return %StringIndexOf(s, ss, start) !== -1; |
| } |
| |
| |
| // ES6 Draft 05-22-2014, section 21.1.3.3 |
| function StringCodePointAt(pos) { |
| CHECK_OBJECT_COERCIBLE(this, "String.prototype.codePointAt"); |
| |
| var string = TO_STRING_INLINE(this); |
| var size = string.length; |
| pos = TO_INTEGER(pos); |
| if (pos < 0 || pos >= size) { |
| return UNDEFINED; |
| } |
| var first = %_StringCharCodeAt(string, pos); |
| if (first < 0xD800 || first > 0xDBFF || pos + 1 == size) { |
| return first; |
| } |
| var second = %_StringCharCodeAt(string, pos + 1); |
| if (second < 0xDC00 || second > 0xDFFF) { |
| return first; |
| } |
| return (first - 0xD800) * 0x400 + second + 0x2400; |
| } |
| |
| |
| // ES6 Draft 05-22-2014, section 21.1.2.2 |
| function StringFromCodePoint(_) { // length = 1 |
| var code; |
| var length = %_ArgumentsLength(); |
| var index; |
| var result = ""; |
| for (index = 0; index < length; index++) { |
| code = %_Arguments(index); |
| if (!%_IsSmi(code)) { |
| code = ToNumber(code); |
| } |
| if (code < 0 || code > 0x10FFFF || code !== TO_INTEGER(code)) { |
| throw MakeRangeError("invalid_code_point", [code]); |
| } |
| if (code <= 0xFFFF) { |
| result += %_StringCharFromCode(code); |
| } else { |
| code -= 0x10000; |
| result += %_StringCharFromCode((code >>> 10) & 0x3FF | 0xD800); |
| result += %_StringCharFromCode(code & 0x3FF | 0xDC00); |
| } |
| } |
| return result; |
| } |
| |
| |
| // ------------------------------------------------------------------- |
| |
| function ExtendStringPrototype() { |
| %CheckIsBootstrapping(); |
| |
| // Set up the non-enumerable functions on the String object. |
| InstallFunctions($String, DONT_ENUM, $Array( |
| "fromCodePoint", StringFromCodePoint |
| )); |
| |
| // Set up the non-enumerable functions on the String prototype object. |
| InstallFunctions($String.prototype, DONT_ENUM, $Array( |
| "codePointAt", StringCodePointAt, |
| "contains", StringContains, |
| "endsWith", StringEndsWith, |
| "repeat", StringRepeat, |
| "startsWith", StringStartsWith |
| )); |
| } |
| |
| ExtendStringPrototype(); |