Speed up identifying keywords in scanner, by using extra table.

runtime/vm/symbols.cc

 // 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.
 
 #include "vm/symbols.h"
 
 #include "vm/handles.h"
 #include "vm/handles_impl.h"
 #include "vm/isolate.h"
 #include "vm/object.h"
@@ skipping 31 matching lines @@
 
 
 const char* Symbols::Name(SymbolId symbol) {
   ASSERT((symbol > kIllegal) && (symbol < kNullCharId));
   return names[symbol];
 }
 
 
 const String& Symbols::Keyword(Token::Kind keyword) {
   const int kw_index = keyword - Token::kFirstKeyword;
-  ASSERT((0 <= kw_index) && (kw_index < Token::numKeywords));
+  ASSERT((0 <= kw_index) && (kw_index < Token::kNumKeywords));
   // First keyword symbol is in symbol_handles_[kKwTableStart + 1].
   const intptr_t keyword_id = Symbols::kKwTableStart + 1 + kw_index;
   ASSERT(symbol_handles_[keyword_id] != NULL);
   return *symbol_handles_[keyword_id];
 }
 
 
 void Symbols::InitOnce(Isolate* isolate) {
   // Should only be run by the vm isolate.
   ASSERT(isolate == Dart::vm_isolate());
@@ skipping 410 matching lines @@
 RawObject* Symbols::GetVMSymbol(intptr_t object_id) {
   ASSERT(IsVMSymbolId(object_id));
   intptr_t i = (object_id - kMaxPredefinedObjectIds);
   if ((i > kIllegal) && (i < Symbols::kMaxPredefinedId)) {
     return symbol_handles_[i]->raw();
   }
   return Object::null();
 }
 
 }  // namespace dart