migrate raw string to new syntax in dartdoc

pkg/dartdoc/lib/dartdoc.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.
 
 /**
  * To generate docs for a library, run this script with the path to an
  * entrypoint .dart file, like:
  *
  *     $ dart dartdoc.dart foo.dart
  *
@@ skipping 218 matching lines @@
 
   int get totalLibraries => _totalLibraries;
   int get totalTypes => _totalTypes;
   int get totalMembers => _totalMembers;
 
   Dartdoc()
       : _comments = new CommentMap() {
     // Patch in support for [:...:]-style code to the markdown parser.
     // TODO(rnystrom): Markdown already has syntax for this. Phase this out?
     md.InlineParser.syntaxes.insertRange(0, 1,
-        new md.CodeSyntax(@'\[\:((?:.|\n)*?)\:\]'));
+        new md.CodeSyntax(r'\[\:((?:.|\n)*?)\:\]'));
 
     md.setImplicitLinkResolver((name) => resolveNameReference(name,
             currentLibrary: _currentLibrary, currentType: _currentType,
             currentMember: _currentMember));
   }
 
   /**
    * Returns `true` if [library] is included in the generated documentation.
    */
   bool shouldIncludeLibrary(LibraryMirror library) {
@@ skipping 282 matching lines @@
       // TODO(3914): Hack to avoid 'file already exists' exception
       // thrown due to invalid result from dir.existsSync() (probably due to
       // race conditions).
       try {
         dir.createSync();
       } on DirectoryIOException catch (e) {
         // Ignore.
       }
     }
     String jsonString = JSON.stringify(createNavigationInfo());
-    String dartString = jsonString.replaceAll(@"$", @"\$");
+    String dartString = jsonString.replaceAll(r"$", r"\$");
     final filePath = tmpPath.append('nav.dart');
     writeString(new File.fromPath(filePath),
         'get json => $dartString;');
   }
 
   Path get tmpPath => dartdocPath.append('tmp');
 
   void cleanup() {
     final dir = new Directory.fromPath(tmpPath);
     if (dir.existsSync()) {
@@ skipping 669 matching lines @@
     // this if the paths overlap.
     return '${repeat('../',
                      countOccurrences(_filePath.toString(), '/'))}$fullPath';
   }
 
   /** Gets whether or not the given URL is absolute or relative. */
   bool isAbsolute(String url) {
     // TODO(rnystrom): Why don't we have a nice type in the platform for this?
     // TODO(rnystrom): This is a bit hackish. We consider any URL that lacks
     // a scheme to be relative.
-    return const RegExp(@'^\w+:').hasMatch(url);
+    return const RegExp(r'^\w+:').hasMatch(url);
   }
 
   /** Gets the URL to the documentation for [library]. */
   String libraryUrl(LibraryMirror library) {
     return '${sanitize(library.simpleName)}.html';
   }
 
   /** Gets the URL for the documentation for [type]. */
   String typeUrl(ObjectMirror type) {
     if (type is LibraryMirror) {
@@ skipping 230 matching lines @@
         return makeLink(memberUrl(foundMember));
       }
     }
 
     // See if it's another type or a member of another type in the current
     // library.
     if (currentLibrary != null) {
       // See if it's a constructor
       final constructorLink = (() {
         final match =
-            new RegExp(@'new ([\w$]+)(?:\.([\w$]+))?').firstMatch(name);
+            new RegExp(r'new ([\w$]+)(?:\.([\w$]+))?').firstMatch(name);
         if (match == null) return;
         InterfaceMirror foundtype = findMirror(currentLibrary.types, match[1]);
         if (foundtype == null) return;
         final constructor =
             findMirror(foundtype.constructors,
                             match[2] == null ? '' : match[2]);
         if (constructor == null) return;
         return makeLink(memberUrl(constructor));
       })();
       if (constructorLink != null) return constructorLink;
 
       // See if it's a member of another type
       final foreignMemberLink = (() {
-        final match = new RegExp(@'([\w$]+)\.([\w$]+)').firstMatch(name);
+        final match = new RegExp(r'([\w$]+)\.([\w$]+)').firstMatch(name);
         if (match == null) return;
         InterfaceMirror foundtype = findMirror(currentLibrary.types, match[1]);
         if (foundtype == null) return;
         MemberMirror foundMember = findMirror(foundtype.declaredMembers, match[2]);
         if (foundMember == null) return;
         return makeLink(memberUrl(foundMember));
       })();
       if (foreignMemberLink != null) return foreignMemberLink;
 
       InterfaceMirror foundType = findMirror(currentLibrary.types, name);
@@ skipping 59 matching lines @@
 
 /**
  * Used to report an unexpected error in the DartDoc tool or the
  * underlying data
  */
 class InternalError {
   final String message;
   const InternalError(this.message);
   String toString() => "InternalError: '$message'";
 }