1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
|
// 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.
// Expects following symbols to be set in the bootstrapper during genesis:
// - symbolHasInstance
// - symbolIsConcatSpreadable
// - symbolIsRegExp
// - symbolIterator
// - symbolToStringTag
// - symbolUnscopables
var $symbolToString;
(function(global, utils) {
"use strict";
%CheckIsBootstrapping();
// -------------------------------------------------------------------
// Imports
var GlobalObject = global.Object;
var GlobalSymbol = global.Symbol;
var ObjectGetOwnPropertyKeys;
var ToString;
utils.Import(function(from) {
ObjectGetOwnPropertyKeys = from.ObjectGetOwnPropertyKeys;
ToString = from.ToString;
});
// -------------------------------------------------------------------
function SymbolConstructor(x) {
if (%_IsConstructCall()) throw MakeTypeError(kNotConstructor, "Symbol");
// NOTE: Passing in a Symbol value will throw on ToString().
return %CreateSymbol(IS_UNDEFINED(x) ? x : ToString(x));
}
function SymbolToString() {
if (!(IS_SYMBOL(this) || IS_SYMBOL_WRAPPER(this))) {
throw MakeTypeError(kIncompatibleMethodReceiver,
"Symbol.prototype.toString", this);
}
var description = %SymbolDescription(%_ValueOf(this));
return "Symbol(" + (IS_UNDEFINED(description) ? "" : description) + ")";
}
function SymbolValueOf() {
if (!(IS_SYMBOL(this) || IS_SYMBOL_WRAPPER(this))) {
throw MakeTypeError(kIncompatibleMethodReceiver,
"Symbol.prototype.valueOf", this);
}
return %_ValueOf(this);
}
function SymbolFor(key) {
key = TO_STRING_INLINE(key);
var registry = %SymbolRegistry();
if (IS_UNDEFINED(registry.for[key])) {
var symbol = %CreateSymbol(key);
registry.for[key] = symbol;
registry.keyFor[symbol] = key;
}
return registry.for[key];
}
function SymbolKeyFor(symbol) {
if (!IS_SYMBOL(symbol)) throw MakeTypeError(kSymbolKeyFor, symbol);
return %SymbolRegistry().keyFor[symbol];
}
// ES6 19.1.2.8
function ObjectGetOwnPropertySymbols(obj) {
obj = TO_OBJECT(obj);
// TODO(arv): Proxies use a shared trap for String and Symbol keys.
return ObjectGetOwnPropertyKeys(obj, PROPERTY_ATTRIBUTES_STRING);
}
//-------------------------------------------------------------------
%SetCode(GlobalSymbol, SymbolConstructor);
%FunctionSetPrototype(GlobalSymbol, new GlobalObject());
utils.InstallConstants(GlobalSymbol, [
// TODO(rossberg): expose when implemented.
// "hasInstance", symbolHasInstance,
// "isConcatSpreadable", symbolIsConcatSpreadable,
// "isRegExp", symbolIsRegExp,
"iterator", symbolIterator,
// TODO(dslomov, caitp): Currently defined in harmony-tostring.js ---
// Move here when shipping
// "toStringTag", symbolToStringTag,
"unscopables", symbolUnscopables
]);
utils.InstallFunctions(GlobalSymbol, DONT_ENUM, [
"for", SymbolFor,
"keyFor", SymbolKeyFor
]);
%AddNamedProperty(
GlobalSymbol.prototype, "constructor", GlobalSymbol, DONT_ENUM);
%AddNamedProperty(
GlobalSymbol.prototype, symbolToStringTag, "Symbol", DONT_ENUM | READ_ONLY);
utils.InstallFunctions(GlobalSymbol.prototype, DONT_ENUM, [
"toString", SymbolToString,
"valueOf", SymbolValueOf
]);
utils.InstallFunctions(GlobalObject, DONT_ENUM, [
"getOwnPropertySymbols", ObjectGetOwnPropertySymbols
]);
$symbolToString = SymbolToString;
})
|
