Rework mirrors implementation.

runtime/vm/json.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_JSON_H_
 #define VM_JSON_H_
 
 #include "vm/allocation.h"
 #include "vm/globals.h"
 
@@ skipping 69 matching lines @@
   JSONType Type() const;
   const char* ValueChars() const {
     return (Type() != kNone) ? scanner_.TokenChars() : NULL;
   }
   int ValueLen() const {
     return (Type() != kNone) ? scanner_.TokenLen() : 0;
   }
   bool IsStringLiteral(const char* literal) const {
     return scanner_.IsStringLiteral(literal);
   }
+  bool IsTrue() const {
+    return scanner_.CurrentToken() == JSONScanner::TokenTrue;
+  }
+  bool IsFalse() const {
+    return scanner_.CurrentToken() == JSONScanner::TokenFalse;
+  }
+  bool IsNull() const {
+    return scanner_.CurrentToken() == JSONScanner::TokenNull;
+  }
 
  private:
   JSONScanner scanner_;
   const char* json_object_;
   bool error_;
 };
 
 
 // TextBuffer maintains a dynamic character buffer with a printf-style way to
 // append text.
@@ skipping 10 matching lines @@
  private:
   void GrowBuffer(intptr_t len);
   char* buf_;
   intptr_t buf_size_;
   intptr_t msg_len_;
 };
 
 }  // namespace dart
 
 #endif  // VM_JSON_H_