Port and integrate the irregexp engine from V8

runtime/lib/regexp_patch.dart

Index: runtime/lib/regexp_patch.dart
diff --git a/runtime/lib/regexp_patch.dart b/runtime/lib/regexp_patch.dart
index 7c9438131082e89df4f2d056c7ca79e62c10e3f6..a9b2649b9f39794844b70dbc07797fd793e261db 100644
--- a/runtime/lib/regexp_patch.dart
+++ b/runtime/lib/regexp_patch.dart
@@ -5,10 +5,35 @@
 patch class RegExp {
   /* patch */ factory RegExp(String source,
                              {bool multiLine: false,
-                              bool caseSensitive: true}) {
-    return new _JSSyntaxRegExp(source,
+                              bool caseSensitive: true}) {    
+    _JSSyntaxRegExpHash hash = new _JSSyntaxRegExpHash(
+	source, multiLine, caseSensitive);
+    if (!_regExpCache.containsKey(hash)) {
+      _regExpCache[hash] = new _JSSyntaxRegExp(source,
                                multiLine: multiLine,
                                caseSensitive: caseSensitive);
+    }
+    
+    return _regExpCache[hash];
+  }
+  
+  static final Map<_JSSyntaxRegExpHash, _JSSyntaxRegExp> _regExpCache =
+      <_JSSyntaxRegExpHash, _JSSyntaxRegExp>{ };
+}
+
+// Represents a key in the regular expression cache.
+class _JSSyntaxRegExpHash {
+  final String pattern;
+  final bool multiLine;
+  final bool caseSensitive;
+  
+  _JSSyntaxRegExpHash(this.pattern, this.multiLine, this.caseSensitive);
+  
+  int get hashCode => pattern.hashCode;
+  bool operator==(_JSSyntaxRegExpHash that) {
+    return (pattern == that.pattern) &&
+           (this.multiLine == that.multiLine) &&
+           (this.caseSensitive == that.caseSensitive);
   }
 }
 
@@ -118,6 +143,51 @@ class _JSSyntaxRegExp implements RegExp {
 
   int get _groupCount native "JSSyntaxRegExp_getGroupCount";
 
+  // Byte map of one byte characters with a 0xff if the character is a word
+  // character (digit, letter or underscore) and 0x00 otherwise.
+  // Used by generated RegExp code.
+  static const List<int> _wordCharacterMap = const <int>[
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // '0' - '7'
+    0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,  // '8' - '9'
+
+    0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // 'A' - 'G'
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // 'H' - 'O'
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // 'P' - 'W'
+    0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0xff,  // 'X' - 'Z', '_'
+
+    0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // 'a' - 'g'
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // 'h' - 'o'
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  // 'p' - 'w'
+    0xff, 0xff, 0xff, 0x00, 0x00, 0x00, 0x00, 0x00,  // 'x' - 'z'
+    // Latin-1 range
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+  ];
+
   List _ExecuteMatch(String str, int start_index)
       native "JSSyntaxRegExp_ExecuteMatch";
 }