Fix-up RegExp implementations.

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 e365f30e5bb7356b983b7fb503cd1707dc223e4c..d82e3305d981a098d003823cc8d5df4369bcb8f4 100644
--- a/runtime/lib/regexp_patch.dart
+++ b/runtime/lib/regexp_patch.dart
@@ -13,21 +13,21 @@ patch class RegExp {
 }
 
 class _JSRegExpMatch implements Match {
-  _JSRegExpMatch(this.regexp, this.str, this._match);
+  _JSRegExpMatch(this._regexp, this.str, this._match);
 
   int get start => _start(0);
   int get end => _end(0);
 
   int _start(int groupIdx) {
-    return _match[(groupIdx * MATCH_PAIR)];
+    return _match[(groupIdx * _MATCH_PAIR)];
   }
 
   int _end(int groupIdx) {
-    return _match[(groupIdx * MATCH_PAIR) + 1];
+    return _match[(groupIdx * _MATCH_PAIR) + 1];
   }
 
   String group(int groupIdx) {
-    if (groupIdx < 0 || groupIdx > regexp._groupCount) {
+    if (groupIdx < 0 || groupIdx > _regexp._groupCount) {
       throw new RangeError.value(groupIdx);
     }
     int startIndex = _start(groupIdx);
@@ -51,14 +51,14 @@ class _JSRegExpMatch implements Match {
     return groupsList;
   }
 
-  int get groupCount => regexp._groupCount;
+  int get groupCount => _regexp._groupCount;
 
-  String get pattern => regexp.pattern;
+  Pattern get pattern => _regexp;
 
-  final RegExp regexp;
+  final RegExp _regexp;
   final String str;
   final List<int> _match;
-  static const int MATCH_PAIR = 2;
+  static const int _MATCH_PAIR = 2;
 }
 
 
@@ -80,20 +80,21 @@ class _JSSyntaxRegExp implements RegExp {
     if (str is! String) throw new ArgumentError(str);
     List<Match> result = new List<Match>();
     int length = str.length;
-    int startIndex = 0;
+    int index = 0;
     while (true) {
-      List match = _ExecuteMatch(str, startIndex);
+      List match = _ExecuteMatch(str, index);
       if (match == null) {
         break;
       }
       result.add(new _JSRegExpMatch(this, str, match));
-      int endIndex = match[1];
-      if (endIndex == length) {
-        break;
-      } else if (match[0] == endIndex) {
-        ++startIndex;  // empty match, advance and restart
-      } else {
-        startIndex = endIndex;
+      // Find the index at which to start searching for the next match.
+      index = match[1];
+      if (match[0] == index) {
+        // Zero-length match.
+        if (index == length) {
+          break;
+        }
+        index++;
       }
     }
     return result;