Change RegExp constructor to insist on proper named optional parameters.

samples/markdown/inline_parser.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.
 
 /// Maintains the internal state needed to parse inline span elements in
 /// markdown.
 class InlineParser {
   static List<InlineSyntax> get syntaxes {
     // Lazy initialize.
     if (_syntaxes == null) {
@@ skipping 122 matching lines @@
     pos += length;
     start = pos;
   }
 }
 
 /// Represents one kind of markdown tag that can be parsed.
 class InlineSyntax {
   final RegExp pattern;
 
   InlineSyntax(String pattern)
-    : pattern = new RegExp(pattern, true);
-  // TODO(rnystrom): Should use named arg for RegExp multiLine.
+    : pattern = new RegExp(pattern, multiLine: true);
 
   bool tryMatch(InlineParser parser) {
     final startMatch = pattern.firstMatch(parser.currentSource);
     if ((startMatch != null) && (startMatch.start() == 0)) {
       // Write any existing plain text up to this point.
       parser.writeText();
 
       if (onMatch(parser, startMatch)) {
         parser.consume(startMatch[0].length);
       }
@@ skipping 43 matching lines @@
 }
 
 /// Matches syntax that has a pair of tags and becomes an element, like `*` for
 /// `<em>`. Allows nested tags.
 class TagSyntax extends InlineSyntax {
   final RegExp endPattern;
   final String tag;
 
   TagSyntax(String pattern, [String tag, String end = null])
     : super(pattern),
-      endPattern = new RegExp((end != null) ? end : pattern, true),
+      endPattern = new RegExp((end != null) ? end : pattern, multiLine: true),
       tag = tag;
     // TODO(rnystrom): Doing this.field doesn't seem to work with named args.
-    // TODO(rnystrom): Should use named arg for RegExp multiLine.
 
   bool onMatch(InlineParser parser, Match match) {
     parser._stack.add(new TagState(parser.pos,
       parser.pos + match[0].length, this));
     return true;
   }
 
   bool onMatchEnd(InlineParser parser, Match match, TagState state) {
     parser.addNode(new Element(tag, state.children));
     return true;
@@ skipping 167 matching lines @@
       parser.consume(endMatch[0].length);
     } else {
       // Didn't close correctly so revert to text.
       parser.start = startPos;
       parser.advanceBy(endMatch[0].length);
     }
 
     return null;
   }
 }