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      1 // Copyright 2013 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 "use strict";
     29 
     30 // This file relies on the fact that the following declaration has been made
     31 // in runtime.js:
     32 // var $Array = global.Array;
     33 
     34 var $Symbol = global.Symbol;
     35 
     36 // -------------------------------------------------------------------
     37 
     38 function SymbolConstructor(x) {
     39   var value =
     40     IS_SYMBOL(x) ? x : %CreateSymbol(IS_UNDEFINED(x) ? x : ToString(x));
     41   if (%_IsConstructCall()) {
     42     %_SetValueOf(this, value);
     43   } else {
     44     return value;
     45   }
     46 }
     47 
     48 function SymbolGetName() {
     49   var symbol = IS_SYMBOL_WRAPPER(this) ? %_ValueOf(this) : this;
     50   if (!IS_SYMBOL(symbol)) {
     51     throw MakeTypeError(
     52         'incompatible_method_receiver', ["Symbol.prototype.name", this]);
     53   }
     54   return %SymbolName(symbol);
     55 }
     56 
     57 function SymbolToString() {
     58   throw MakeTypeError('symbol_to_string');
     59 }
     60 
     61 function SymbolValueOf() {
     62   // NOTE: Both Symbol objects and values can enter here as
     63   // 'this'. This is not as dictated by ECMA-262.
     64   if (!IS_SYMBOL(this) && !IS_SYMBOL_WRAPPER(this)) {
     65     throw MakeTypeError(
     66         'incompatible_method_receiver', ["Symbol.prototype.valueOf", this]);
     67   }
     68   return %_ValueOf(this);
     69 }
     70 
     71 //-------------------------------------------------------------------
     72 
     73 function SetUpSymbol() {
     74   %CheckIsBootstrapping();
     75 
     76   %SetCode($Symbol, SymbolConstructor);
     77   %FunctionSetPrototype($Symbol, new $Symbol());
     78   %SetProperty($Symbol.prototype, "constructor", $Symbol, DONT_ENUM);
     79 
     80   InstallGetter($Symbol.prototype, "name", SymbolGetName);
     81   InstallFunctions($Symbol.prototype, DONT_ENUM, $Array(
     82     "toString", SymbolToString,
     83     "valueOf", SymbolValueOf
     84   ));
     85 }
     86 
     87 SetUpSymbol();
     88