text: // Copyright 2013 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE.chromium file.
  
  #ifndef NATIVE_MATE_CONVERTER_H_
  #define NATIVE_MATE_CONVERTER_H_
  
  #include <string>
  #include <vector>
  
  #include "base/strings/string_piece.h"
  #include "native_mate/compat.h"
  #include "v8/include/v8.h"
  
  namespace mate {
  
  template<typename T, typename Enable = void>
  struct Converter {};
  
  template<>
  struct Converter<void*> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate, void* val) {
      return MATE_UNDEFINED(isolate);
    }
  };
  
  template<>
  struct Converter<bool> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      bool val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       bool* out);
  };
  
  template<>
  struct Converter<int32_t> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      int32_t val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       int32_t* out);
  };
  
  template<>
  struct Converter<uint32_t> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      uint32_t val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       uint32_t* out);
  };
  
  template<>
  struct Converter<int64_t> {
    // Warning: JavaScript cannot represent 64 integers precisely.
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      int64_t val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       int64_t* out);
  };
  
  template<>
  struct Converter<uint64_t> {
    // Warning: JavaScript cannot represent 64 integers precisely.
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      uint64_t val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       uint64_t* out);
  };
  
  template<>
  struct Converter<float> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      float val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       float* out);
  };
  
  template<>
  struct Converter<double> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      double val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       double* out);
  };
  
  template<>
  struct Converter<const char*> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate, const char* val);
  };
  
  template<>
  struct Converter<base::StringPiece> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      const base::StringPiece& val);
    // No conversion out is possible because StringPiece does not contain storage.
  };
  
  template<>
  struct Converter<std::string> {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      const std::string& val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       std::string* out);
  };
  
  template<>
  struct Converter<v8::Handle<v8::Function> > {
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       v8::Handle<v8::Function>* out);
  };
  
  template<>
  struct Converter<v8::Handle<v8::Object> > {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      v8::Handle<v8::Object> val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       v8::Handle<v8::Object>* out);
  };
  
  template<>
  struct Converter<v8::Handle<v8::String> > {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      v8::Handle<v8::String> val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       v8::Handle<v8::String>* out);
  };
  
  template<>
  struct Converter<v8::Handle<v8::External> > {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      v8::Handle<v8::External> val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       v8::Handle<v8::External>* out);
  };
  
  template<>
  struct Converter<v8::Handle<v8::Value> > {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      v8::Handle<v8::Value> val);
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       v8::Handle<v8::Value>* out);
  };
  
  template<typename T>
  struct Converter<std::vector<T> > {
    static v8::Handle<v8::Value> ToV8(v8::Isolate* isolate,
                                      const std::vector<T>& val) {
      v8::Handle<v8::Array> result(
          MATE_ARRAY_NEW(isolate, static_cast<int>(val.size())));
      for (size_t i = 0; i < val.size(); ++i) {
        result->Set(static_cast<int>(i), Converter<T>::ToV8(isolate, val[i]));
      }
      return result;
    }
  
    static bool FromV8(v8::Isolate* isolate,
                       v8::Handle<v8::Value> val,
                       std::vector<T>* out) {
      if (!val->IsArray())
        return false;
  
      std::vector<T> result;
      v8::Handle<v8::Array> array(v8::Handle<v8::Array>::Cast(val));
      uint32_t length = array->Length();
      for (uint32_t i = 0; i < length; ++i) {
        T item;
        if (!Converter<T>::FromV8(isolate, array->Get(i), &item))
          return false;
        result.push_back(item);
      }
  
      out->swap(result);
      return true;
    }
  };
  
  // Convenience functions that deduce T.
  template<typename T>
  v8::Handle<v8::Value> ConvertToV8(v8::Isolate* isolate,
                                    T input) {
    return Converter<T>::ToV8(isolate, input);
  }
  
  inline v8::Handle<v8::String> StringToV8(
      v8::Isolate* isolate,
      const base::StringPiece& input) {
    return ConvertToV8(isolate, input).As<v8::String>();
  }
  
  v8::Handle<v8::String> StringToSymbol(v8::Isolate* isolate,
                                        const base::StringPiece& input);
  
  template<typename T>
  bool ConvertFromV8(v8::Isolate* isolate, v8::Handle<v8::Value> input,
                     T* result) {
    return Converter<T>::FromV8(isolate, input, result);
  }
  
  std::string V8ToString(v8::Handle<v8::Value> value);
  
  }  // namespace mate
  
  #endif  // NATIVE_MATE_CONVERTER_H_
  