runtime/JSArgumentsIterator.h

   1 /*
   2  * Copyright (C) 2013 Apple, Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  26 #ifndef JSArgumentsIterator_h
  27 #define JSArgumentsIterator_h
  28
  29 #include "Arguments.h"
  30
  31 namespace JSC {
  32
  33 class JSArgumentsIterator : public JSNonFinalObject {
  34 public:
  35     typedef JSNonFinalObject Base;
  36
  37     DECLARE_EXPORT_INFO;
  38
  39     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
  40     {
  41         return Structure::create(vm, globalObject, prototype, TypeInfo(ObjectType, StructureFlags), info());
  42     }
  43
  44     static JSArgumentsIterator* create(VM& vm, Structure* structure, Arguments* arguments)
  45     {
  46         JSArgumentsIterator* instance = new (NotNull, allocateCell<JSArgumentsIterator>(vm.heap)) JSArgumentsIterator(vm, structure);
  47         instance->finishCreation(vm, arguments);
  48         return instance;
  49     }
  50
  51     bool next(CallFrame* callFrame, JSValue& value)
  52     {
  53         if (m_nextIndex >= m_arguments->length(callFrame))
  54             return false;
  55         value = m_arguments->tryGetArgument(m_nextIndex++);
  56         if (!value)
  57             value = jsUndefined();
  58         return true;
  59     }
  60
  61 private:
  62
  63     static const unsigned StructureFlags = Base::StructureFlags;
  64
  65     JSArgumentsIterator(VM& vm, Structure* structure)
  66         : Base(vm, structure)
  67         , m_nextIndex(0)
  68     {
  69     }
  70
  71     void finishCreation(VM&, Arguments*);
  72
  73     WriteBarrier<Arguments> m_arguments;
  74     size_t m_nextIndex;
  75 };
  76
  77 }
  78
  79 #endif // !defined(JSArgumentsIterator_h)