runtime/Symbol.h

   1 /*
   2  * Copyright (C) 2012 Apple Inc. All rights reserved.
   3  * Copyright (C) 2014 Apple Inc. All rights reserved.
   4  * Copyright (C) 2015 Yusuke Suzuki <utatane.tea@gmail.com>.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  17  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  19  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  25  * THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #ifndef Symbol_h
  29 #define Symbol_h
  30
  31 #include "JSCell.h"
  32 #include "JSString.h"
  33 #include "PrivateName.h"
  34
  35 namespace JSC {
  36
  37 class Symbol final : public JSCell {
  38 public:
  39     typedef JSCell Base;
  40     static const unsigned StructureFlags = Base::StructureFlags | OverridesGetOwnPropertySlot | InterceptsGetOwnPropertySlotByIndexEvenWhenLengthIsNotZero | StructureIsImmortal;
  41
  42     DECLARE_EXPORT_INFO;
  43
  44     static const bool needsDestruction = true;
  45
  46     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
  47     {
  48         return Structure::create(vm, globalObject, prototype, TypeInfo(SymbolType, StructureFlags), info());
  49     }
  50
  51     static Symbol* create(VM& vm)
  52     {
  53         Symbol* symbol = new (NotNull, allocateCell<Symbol>(vm.heap)) Symbol(vm);
  54         symbol->finishCreation(vm);
  55         return symbol;
  56     }
  57
  58     static Symbol* create(ExecState* exec, JSString* description)
  59     {
  60         VM& vm = exec->vm();
  61         String desc = description->value(exec);
  62         Symbol* symbol = new (NotNull, allocateCell<Symbol>(vm.heap)) Symbol(vm, desc);
  63         symbol->finishCreation(vm);
  64         return symbol;
  65     }
  66
  67     static Symbol* create(VM& vm, SymbolImpl& uid)
  68     {
  69         Symbol* symbol = new (NotNull, allocateCell<Symbol>(vm.heap)) Symbol(vm, uid);
  70         symbol->finishCreation(vm);
  71         return symbol;
  72     }
  73
  74     const PrivateName& privateName() const { return m_privateName; }
  75     String descriptiveString() const;
  76
  77     JSValue toPrimitive(ExecState*, PreferredPrimitiveType) const;
  78     bool getPrimitiveNumber(ExecState*, double& number, JSValue&) const;
  79     JSObject* toObject(ExecState*, JSGlobalObject*) const;
  80     double toNumber(ExecState*) const;
  81
  82 protected:
  83     static void destroy(JSCell*);
  84
  85     Symbol(VM&);
  86     Symbol(VM&, const String&);
  87     Symbol(VM&, SymbolImpl& uid);
  88
  89     void finishCreation(VM& vm)
  90     {
  91         Base::finishCreation(vm);
  92         ASSERT(inherits(info()));
  93     }
  94
  95     PrivateName m_privateName;
  96 };
  97
  98 Symbol* asSymbol(JSValue);
  99
 100 inline Symbol* asSymbol(JSValue value)
 101 {
 102     ASSERT(value.asCell()->isSymbol());
 103     return jsCast<Symbol*>(value.asCell());
 104 }
 105
 106 } // namespace JSC
 107
 108 #endif // Symbol_h