First partial step at removing interfaces in libraries.

lib/core/regexp.dart

 // Copyright (c) 2011, 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.
 
 /**
  * [Match] contains methods to manipulate a regular expression match.
  *
  * Iterables of [Match] objects are returned from [RegExp] matching methods.
  *
  * The following example finds all matches of a [RegExp] in a [String]
  * and iterates through the returned iterable of [Match] objects.
  *
  *     RegExp exp = const RegExp(@"(\w+)");
  *     String str = "Parse my string";
  *     Iterable<Match> matches = exp.allMatches(str);
  *     for (Match m in matches) {
  *       String match = m.group(0);
  *       print(match);
  *     };
  *
  * The output of the example is:
  *
  *     Parse
  *     my
  *     string
  */
-interface Match {
+abstract class Match {
   /**
    * Returns the index in the string where the match starts.
    */
   int start();
 
   /**
    * Returns the index in the string after the last character of the
    * match.
    */
   int end();
@@ skipping 12 matching lines @@
   List<String> groups(List<int> groups);
 
   /**
    * Returns the number of groups in the regular expression.
    */
   int groupCount();
 
   /**
    * The string on which this matcher was computed.
    */
-  final String str;
+  String get str;
 
   /**
    * The pattern to search for in [str].
    */
-  final Pattern pattern;
+  Pattern get pattern;
 }
 
 
 /**
  * [RegExp] represents regular expressions.
  *
  * [firstMatch] is the main implementation method that applies a regular
  * expression to a string and returns the first [Match]. All
  * other methods in [RegExp] can build on it.
  *
@@ skipping 34 matching lines @@
 
   /**
    * Searches for the first match of the regular expression
    * in the string [str] and returns the matched string.
    */
   String stringMatch(String str);
 
   /**
    * The pattern of this regular expression.
    */
-  final String pattern;
+  String get pattern;
 
   /**
    * Whether this regular expression matches multiple lines.
    */
-  final bool multiLine;
+  bool get multiLine;
 
   /**
    * Whether this regular expression is case insensitive.
    */
-  final bool ignoreCase;
+  bool get ignoreCase;
 }