Change Uri.fromComponents to take named optional arguments.

lib/uri/uri.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.
 
 #library('dart:uri');
 
 #import('dart:math');
 #import('dart:utf');
 
 #source('encode_decode.dart');
 #source('helpers.dart');
 
 /**
  * A parsed URI, inspired by Closure's [URI][] class. Implements [RFC-3986][].
  * [uri]: http://closure-library.googlecode.com/svn/docs/class_goog_Uri.html
  * [RFC-3986]: http://tools.ietf.org/html/rfc3986#section-4.3)
  */
 class Uri {
   final String scheme;
   final String userInfo;
   final String domain;
   final int port;
   final String path;
   final String query;
   final String fragment;
 
   Uri.fromString(String uri) : this._fromMatch(_splitRe.firstMatch(uri));
 
   Uri._fromMatch(Match m) :
-    this.fromComponents(_emptyIfNull(m[_COMPONENT_SCHEME]),
-                        _emptyIfNull(m[_COMPONENT_USER_INFO]),
-                        _emptyIfNull(m[_COMPONENT_DOMAIN]),
-                        _parseIntOrZero(m[_COMPONENT_PORT]),
-                        _emptyIfNull(m[_COMPONENT_PATH]),
-                        _emptyIfNull(m[_COMPONENT_QUERY_DATA]),
-                        _emptyIfNull(m[_COMPONENT_FRAGMENT]));
+    this.fromComponents(scheme: _emptyIfNull(m[_COMPONENT_SCHEME]),
+                        userInfo: _emptyIfNull(m[_COMPONENT_USER_INFO]),
+                        domain: _emptyIfNull(m[_COMPONENT_DOMAIN]),
+                        port: _parseIntOrZero(m[_COMPONENT_PORT]),
+                        path: _emptyIfNull(m[_COMPONENT_PATH]),
+                        query: _emptyIfNull(m[_COMPONENT_QUERY_DATA]),
+                        fragment: _emptyIfNull(m[_COMPONENT_FRAGMENT]));
 
-  const Uri.fromComponents([String this.scheme = "", String this.userInfo ="",
-                            String this.domain = "", int this.port = 0,
-                            String this.path = "", String this.query = "",
-                            String this.fragment = ""]);
+  const Uri.fromComponents({this.scheme: "",
+                            this.userInfo: "",
+                            this.domain: "",
+                            this.port: 0,
+                            this.path: "",
+                            this.query: "",
+                            this.fragment: ""});
 
   Uri(String uri) : this.fromString(uri);
 
   static String _emptyIfNull(String val) => val != null ? val : '';
 
   static int _parseIntOrZero(String val) {
     if (val !== null && val != '') {
       return parseInt(val);
     } else {
       return 0;
@@ skipping 104 matching lines @@
             targetPath = removeDotSegments(merge(this.path, reference.path));
           }
           targetQuery = reference.query;
         }
         targetUserInfo = this.userInfo;
         targetDomain = this.domain;
         targetPort = this.port;
       }
       targetScheme = this.scheme;
     }
-    return new Uri.fromComponents(targetScheme, targetUserInfo, targetDomain,
-                                  targetPort, targetPath, targetQuery,
-                                  reference.fragment);
+    return new Uri.fromComponents(scheme: targetScheme,
+                                  userInfo: targetUserInfo,
+                                  domain: targetDomain,
+                                  port: targetPort,
+                                  path: targetPath,
+                                  query: targetQuery,
+                                  fragment: reference.fragment);
   }
 
   bool hasAuthority() {
     return (userInfo != "") || (domain != "") || (port != 0);
   }
 
   /**
    * For http/https schemes returns URI's [origin][] - scheme://domain:port.
    * For all other schemes throws IllegalArgumentException.
    * [origin]: http://www.w3.org/TR/2011/WD-html5-20110405/origin-0.html#origin
@@ skipping 44 matching lines @@
   }
 
   static void _addIfNonEmpty(StringBuffer sb, String test,
                              String first, String second) {
     if ("" != test) {
       sb.add(first === null ? "null" : first);
       sb.add(second === null ? "null" : second);
     }
   }
 }