Add Uri.directory constructor.

sdk/lib/core/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.
 
 part of dart.core;
 
 /**
  * A parsed URI, such as a URL.
  *
  * **See also:**
@@ skipping 686 matching lines @@
    * // This throws an error. A path with a drive letter is not absolute.
    * new Uri.file(r"C:xxx\yyy", windows: true);
    *
    * // file://server/share/file
    * new Uri.file(r"\\server\share\file", windows: true);
    * ```
    *
    * If the path passed is not a legal file path [ArgumentError] is thrown.
    */
   factory Uri.file(String path, {bool windows}) {
-    windows = windows == null ? Uri._isWindows : windows;
-    return windows ? _makeWindowsFileUrl(path) : _makeFileUri(path);
+    windows = (windows == null) ? Uri._isWindows : windows;
+    return windows ? _makeWindowsFileUrl(path, false)
+                   : _makeFileUri(path, false);
   }
 
   /**
+   * Like [Uri.file] except that a non-empty URI path ends in a slash.
+   *
+   * If [path] is not empty, and it doesn't end in a directory separator,
+   * then a slash is added to the returned URI's path.
+   * In all other cases, the result is the same as returned by `Uri.file`.
+   */
+  factory Uri.directory(String path, {bool windows}) {
+    windows = (windows == null) ? Uri._isWindows : windows;
+    return windows ? _makeWindowsFileUrl(path, true)
+                   : _makeFileUri(path, true);
+  }
+
+  /**
    * Returns the natural base URI for the current platform.
    *
    * When running in a browser this is the current URL (from
    * `window.location.href`).
    *
    * When not running in a browser this is the file URI referencing
    * the current working directory.
    */
   external static Uri get base;
 
@@ skipping 33 matching lines @@
     }
     if (argumentError) {
       throw new ArgumentError("Illegal drive letter " +
                               new String.fromCharCode(charCode));
     } else {
       throw new UnsupportedError("Illegal drive letter " +
                               new String.fromCharCode(charCode));
     }
   }
 
-  static _makeFileUri(String path) {
+  static _makeFileUri(String path, bool slashTerminated) {

[Søren Gjesse, 2015/04/17 08:33:21]

Optional named argument for documentation in the above use?

[Lasse Reichstein Nielsen, 2015/04/17 08:41:40]

No optional arguments for internal functions.
It's a waste of processor power to bother for something that is only used
internally.

     const String sep = "/";
+    var segments = path.split(sep);
+    if (slashTerminated &&
+        segments.isNotEmpty &&
+        segments.last.isNotEmpty) {
+      segments.add("");  // Extra separator at end.
+    }
     if (path.startsWith(sep)) {
       // Absolute file:// URI.
-      return new Uri(scheme: "file", pathSegments: path.split(sep));
+      return new Uri(scheme: "file", pathSegments: segments);
     } else {
       // Relative URI.
-      return new Uri(pathSegments: path.split(sep));
+      return new Uri(pathSegments: segments);
     }
   }
 
-  static _makeWindowsFileUrl(String path) {
+  static _makeWindowsFileUrl(String path, bool slashTerminated) {
     if (path.startsWith(r"\\?\")) {
       if (path.startsWith(r"UNC\", 4)) {
         path = path.replaceRange(0, 7, r'\');
       } else {
         path = path.substring(4);
         if (path.length < 3 ||
             path.codeUnitAt(1) != _COLON ||
             path.codeUnitAt(2) != _BACKSLASH) {
           throw new ArgumentError(
               r"Windows paths with \\?\ prefix must be absolute");
         }
       }
     } else {
       path = path.replaceAll("/", r'\');
     }
     const String sep = r'\';
     if (path.length > 1 && path.codeUnitAt(1) == _COLON) {
       _checkWindowsDriveLetter(path.codeUnitAt(0), true);
       if (path.length == 2 || path.codeUnitAt(2) != _BACKSLASH) {
         throw new ArgumentError(
             "Windows paths with drive letter must be absolute");
       }
       // Absolute file://C:/ URI.
       var pathSegments = path.split(sep);
+      if (slashTerminated &&
+          pathSegments.last.isNotEmpty) {
+        pathSegments.add("");  // Extra separator at end.
+      }
       _checkWindowsPathReservedCharacters(pathSegments, true, 1);
       return new Uri(scheme: "file", pathSegments: pathSegments);
     }
 
     if (path.startsWith(sep)) {
       if (path.startsWith(sep, 1)) {
         // Absolute file:// URI with host.
         int pathStart = path.indexOf(r'\', 2);
         String hostPart =
             (pathStart < 0) ? path.substring(2) : path.substring(2, pathStart);
         String pathPart =
             (pathStart < 0) ? "" : path.substring(pathStart + 1);
         var pathSegments = pathPart.split(sep);
         _checkWindowsPathReservedCharacters(pathSegments, true);
+        if (slashTerminated &&
+            pathSegments.last.isNotEmpty) {
+          pathSegments.add("");  // Extra separator at end.
+        }
         return new Uri(
             scheme: "file", host: hostPart, pathSegments: pathSegments);
       } else {
         // Absolute file:// URI.
         var pathSegments = path.split(sep);
+        if (slashTerminated &&
+            pathSegments.last.isNotEmpty) {
+          pathSegments.add("");  // Extra separator at end.
+        }
         _checkWindowsPathReservedCharacters(pathSegments, true);
         return new Uri(scheme: "file", pathSegments: pathSegments);
       }
     } else {
       // Relative URI.
       var pathSegments = path.split(sep);
       _checkWindowsPathReservedCharacters(pathSegments, true);
+      if (slashTerminated &&
+          pathSegments.isNotEmpty &&
+          pathSegments.last.isNotEmpty) {
+        pathSegments.add("");  // Extra separator at end.
+      }
       return new Uri(pathSegments: pathSegments);
     }
   }
 
   /**
    * Returns a new `Uri` based on this one, but with some parts replaced.
    *
    * This method takes the same parameters as the [new Uri] constructor,
    * and they have the same meaning.
    *
@@ skipping 1590 matching lines @@
       0xafff,   // 0x30 - 0x3f  1111111111110101
                 //              @ABCDEFGHIJKLMNO
       0xffff,   // 0x40 - 0x4f  1111111111111111
                 //              PQRSTUVWXYZ    _
       0x87ff,   // 0x50 - 0x5f  1111111111100001
                 //               abcdefghijklmno
       0xfffe,   // 0x60 - 0x6f  0111111111111111
                 //              pqrstuvwxyz   ~
       0x47ff];  // 0x70 - 0x7f  1111111111100010
 }