Added support functions for using Literal keys in a HashMap.

src/ast.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1193 matching lines @@
   template<class> friend class AstNodeFactory;
 
   EmptyStatement() {}
 };
 
 
 class Literal: public Expression {
  public:
   DECLARE_NODE_TYPE(Literal)
 
-  // Check if this literal is identical to the other literal.
-  bool IsIdenticalTo(const Literal* other) const {
-    return handle_.is_identical_to(other->handle_);
-  }
-
   virtual bool IsPropertyName() {
     if (handle_->IsSymbol()) {
       uint32_t ignored;
       return !String::cast(*handle_)->AsArrayIndex(&ignored);
     }
     return false;
   }
 
   Handle<String> AsPropertyName() {
     ASSERT(IsPropertyName());
@@ skipping 12 matching lines @@
     ASSERT(!handle_.is_null());
     return handle_->IsTrue();
   }
   bool IsFalse() const {
     ASSERT(!handle_.is_null());
     return handle_->IsFalse();
   }
 
   Handle<Object> handle() const { return handle_; }
 
+  // Support for using Literal as a HashMap key. NOTE: Currently, this works
+  // only for string and number literals!
+  uint32_t Hash() { return ToString()->Hash(); }
+
+  static bool Match(void* literal1, void* literal2) {
+    Handle<String> s1 = static_cast<Literal*>(literal1)->ToString();
+    Handle<String> s2 = static_cast<Literal*>(literal2)->ToString();
+    return s1->Equals(*s2);
+  }
+
  protected:
   template<class> friend class AstNodeFactory;
 
   Literal(Isolate* isolate, Handle<Object> handle)
       : Expression(isolate),
         handle_(handle) { }
 
  private:
+  Handle<String> ToString();
+
   Handle<Object> handle_;
 };
 
 
 // Base class for literals that needs space in the corresponding JSFunction.
 class MaterializedLiteral: public Expression {
  public:
   virtual MaterializedLiteral* AsMaterializedLiteral() { return this; }
 
   int literal_index() { return literal_index_; }
@@ skipping 1684 matching lines @@
  private:
   Isolate* isolate_;
   Zone* zone_;
   Visitor visitor_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_AST_H_