Tentative implementation of string slices (hidden under the flag --string-slices).

src/handles.cc

 // Copyright 2011 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 232 matching lines @@
 void FlattenString(Handle<String> string) {
   CALL_HEAP_FUNCTION_VOID(string->GetIsolate(), string->TryFlatten());
 }
 
 
 Handle<String> FlattenGetString(Handle<String> string) {
   CALL_HEAP_FUNCTION(string->GetIsolate(), string->TryFlatten(), String);
 }
 
 
+void TruncateString(Handle<String> string) {
+  CALL_HEAP_FUNCTION_VOID(string->GetIsolate(), string->TryTruncate());
+}
+
+
+Handle<String> TruncateGetString(Handle<String> string) {
+  CALL_HEAP_FUNCTION(string->GetIsolate(), string->TryTruncate(), String);
+}
+
+
+void FlattenOrTruncateString(Handle<String> string) {
+  CALL_HEAP_FUNCTION_VOID(string->GetIsolate(), string->TryFlattenOrTruncate());
+}
+
+
 Handle<Object> SetPrototype(Handle<JSFunction> function,
                             Handle<Object> prototype) {
   ASSERT(function->should_have_prototype());
   CALL_HEAP_FUNCTION(function->GetIsolate(),
                      Accessors::FunctionSetPrototype(*function,
                                                      *prototype,
                                                      NULL),
                      Object);
 }
 
@@ skipping 703 matching lines @@
 
 bool CompileOptimized(Handle<JSFunction> function,
                       int osr_ast_id,
                       ClearExceptionFlag flag) {
   CompilationInfo info(function);
   info.SetOptimizing(osr_ast_id);
   return CompileLazyHelper(&info, flag);
 }
 
 } }  // namespace v8::internal