Convert raw strings in pub (and apidoc) to new syntax.

utils/pub/yaml/composer.dart

 // Copyright (c) 2012, 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.
 
 /**
  * Takes a parsed YAML document (what the spec calls the "serialization tree")
  * and resolves aliases, resolves tags, and parses scalars to produce the
  * "representation graph".
  */
 class _Composer extends _Visitor {
@@ skipping 136 matching lines @@
   }
 
   /** Parses a floating-point scalar. */
   _ScalarNode parseFloat(String content) {
     var match = const RegExp(
         "^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?\$").
       firstMatch(content);
     if (match != null) {
       // YAML allows floats of the form "0.", but Dart does not. Fix up those
       // floats by removing the trailing dot.
-      var matchStr = match.group(0).replaceAll(new RegExp(@"\.$"), "");
+      var matchStr = match.group(0).replaceAll(new RegExp(r"\.$"), "");
       return new _ScalarNode(_Tag.yaml("float"),
           value: Math.parseDouble(matchStr));
     }
 
     match = const RegExp("^([+-]?)\.(inf|Inf|INF)\$").firstMatch(content);
     if (match != null) {
       var infinityStr = match.group(1) == "-" ? "-Infinity" : "Infinity";
       return new _ScalarNode(_Tag.yaml("float"),
           value: Math.parseDouble(infinityStr));
     }
 
     match = const RegExp("^\.(nan|NaN|NAN)\$").firstMatch(content);
     if (match != null) {
       return new _ScalarNode(_Tag.yaml("float"),
           value: Math.parseDouble("NaN"));
     }
 
     return null;
   }
 
   /** Parses a string scalar. */
   _ScalarNode parseString(String content) =>
     new _ScalarNode(_Tag.yaml("str"), value: content);
 }