Begin implementing V8 bindings for Mojo

gin/arguments.h

Index: gin/arguments.h
diff --git a/gin/arguments.h b/gin/arguments.h
new file mode 100644
index 0000000000000000000000000000000000000000..8b494baf0a11ad067b17bb78dcf7bbbac8137e16
--- /dev/null
+++ b/gin/arguments.h
@@ -0,0 +1,50 @@
+// 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 file.
+
+#ifndef GIN_ARGUMENTS_H_
+#define GIN_ARGUMENTS_H_
+
+#include "base/basictypes.h"
+#include "gin/converter.h"
+
+namespace gin {
+
+class Arguments {
+ public:
+  explicit Arguments(const v8::FunctionCallbackInfo<v8::Value>& info);
+  ~Arguments();
+
+  template<typename T>
+  bool Holder(T* out) {
+    return ConvertFromV8(info_.Holder(), out);
+  }
+
+  template<typename T>
+  bool Next(T* out) {

[Aaron Boodman, 2013/11/11 19:01:08]

I think we'll eventually need Get(index) too, but that can be added when needed.
For simple cases, Next() is a bit cleaner-looking than having all the magic
numbers for argument positions at the call site.

[Aaron Boodman, 2013/11/11 19:01:08]

I feel like it is Chromium (or Google) style to use have method names be verb
phrases, so GetNext() instead of Next().

[abarth-chromium, 2013/11/11 20:17:42]

Will do.

+    if (current_ >= info_.Length())
+      return false;
+    v8::Handle<v8::Value> val = info_[current_++];
+    return ConvertFromV8(val, out);
+  }
+
+  template<typename T>
+  void Return(T val) {
+    info_.GetReturnValue().Set(ConvertToV8(isolate_, val));
+  }
+
+  void ThrowTypeError(const char* message);
+
+  v8::Isolate* isolate() const { return isolate_; }
+
+ private:
+  v8::Isolate* isolate_;
+  const v8::FunctionCallbackInfo<v8::Value>& info_;
+  int current_;
+
+  DISALLOW_COPY_AND_ASSIGN(Arguments);
+};
+
+}  // namespace gin
+
+#endif  // GIN_ARGUMENTS_H_