Attempt to make \b\w+ faster. Slight performance increase on, e.g., string unpacking.

test/cctest/test-regexp.cc

 // Copyright 2008 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 1532 matching lines @@
       CHECK_EQ(in_overlay, InClass(i, included));
       CHECK_EQ(!in_overlay, InClass(i, excluded));
     } else {
       CHECK(!InClass(i, included));
       CHECK(!InClass(i, excluded));
     }
   }
 }
 
 
+TEST(CanonicalizeCharacterSets) {
+  ZoneScope scope(DELETE_ON_EXIT);
+  ZoneList<CharacterRange>* list = new ZoneList<CharacterRange>(4);
+  CharacterSet set(list);
+
+  list->Add(CharacterRange(10, 20));
+  list->Add(CharacterRange(30, 40));
+  list->Add(CharacterRange(50, 60));
+  set.Canonicalize();
+  ASSERT_EQ(3, list->length());
+  ASSERT_EQ(10, list->at(0).from());
+  ASSERT_EQ(20, list->at(0).to());
+  ASSERT_EQ(30, list->at(1).from());
+  ASSERT_EQ(40, list->at(1).to());
+  ASSERT_EQ(50, list->at(2).from());
+  ASSERT_EQ(60, list->at(2).to());
+
+  list->Rewind(0);
+  list->Add(CharacterRange(10, 20));
+  list->Add(CharacterRange(50, 60));
+  list->Add(CharacterRange(30, 40));
+  set.Canonicalize();
+  ASSERT_EQ(3, list->length());
+  ASSERT_EQ(10, list->at(0).from());
+  ASSERT_EQ(20, list->at(0).to());
+  ASSERT_EQ(30, list->at(1).from());
+  ASSERT_EQ(40, list->at(1).to());
+  ASSERT_EQ(50, list->at(2).from());
+  ASSERT_EQ(60, list->at(2).to());
+
+  list->Rewind(0);
+  list->Add(CharacterRange(30, 40));
+  list->Add(CharacterRange(10, 20));
+  list->Add(CharacterRange(25, 25));
+  list->Add(CharacterRange(100, 100));
+  list->Add(CharacterRange(1, 1));
+  set.Canonicalize();
+  ASSERT_EQ(5, list->length());
+  ASSERT_EQ(1, list->at(0).from());
+  ASSERT_EQ(1, list->at(0).to());
+  ASSERT_EQ(10, list->at(1).from());
+  ASSERT_EQ(20, list->at(1).to());
+  ASSERT_EQ(25, list->at(2).from());
+  ASSERT_EQ(25, list->at(2).to());
+  ASSERT_EQ(30, list->at(3).from());
+  ASSERT_EQ(40, list->at(3).to());
+  ASSERT_EQ(100, list->at(4).from());
+  ASSERT_EQ(100, list->at(4).to());
+
+  list->Rewind(0);
+  list->Add(CharacterRange(10, 19));
+  list->Add(CharacterRange(21, 30));
+  list->Add(CharacterRange(20, 20));
+  set.Canonicalize();
+  ASSERT_EQ(1, list->length());
+  ASSERT_EQ(10, list->at(0).from());
+  ASSERT_EQ(30, list->at(0).to());
+}
+
+
+
 TEST(Graph) {
   V8::Initialize(NULL);
-  Execute("(?:(?:x(.))?\1)+$", false, true, true);
+  Execute("\\b\\w+\\b", false, true, true);
 }