Error reporting on File in dart:io

runtime/bin/common.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.
+
+/** 
+  * Class for holding information on an error that was returned from the
+  * operating system.
+  */
+class OSError {
+  static int noErrorCode = -1;
+
+  const OSError([String this.message, int this.errorCode = -1]);
+
+  String toString() {
+    StringBuffer sb = new StringBuffer();
+    sb.add("OS Error");
+    if (message != null && message.length > 0) {
+      sb.add(": ");
+      sb.add(message);
+      if (errorCode != noErrorCode) {
+        sb.add(", errno = ");
+        sb.add(errorCode.toString());
+      }
+    } else if (errorCode != noErrorCode) {
+      sb.add(": errno = ");
+      sb.add(errorCode.toString());
+    }
+    return sb.toString();
+  }
+
+  /**
+    * Error message supplied by the operating system. null if no message is
+    * associated with the error.
+    */
+  final String message;
+
+  /**
+    * Error code supplied by the operating system. Will have the value
+    * [noErrorCode] if there is no error code associated with the error.
+    */
+  final int errorCode;
+}
+
+
+class IOUtils {
+  static OSError makeOSError(message, code) => new OSError(message, code);

[Mads Ager (google), 2012/03/09 09:40:13]

We should get rid of this public class and public static method. We just need to
figure out how to construct an object through the API (or expose the
functionality in the API if it is not there).

[Søren Gjesse, 2012/03/13 08:25:55]

Added TODO and filed issue 2081.

+}