Add a CommandRunner class for dispatching commands to args.

pkg/args/lib/src/utils.dart

Index: pkg/args/lib/src/utils.dart
diff --git a/pkg/args/lib/src/utils.dart b/pkg/args/lib/src/utils.dart
new file mode 100644
index 0000000000000000000000000000000000000000..9e71f50a82b6b8541e464b45b63092365da4181e
--- /dev/null
+++ b/pkg/args/lib/src/utils.dart
@@ -0,0 +1,17 @@
+// Copyright (c) 2014, 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 args.utils;
+
+/// Pads [source] to [length] by adding spaces at the end.
+String padRight(String source, int length) {
+  final result = new StringBuffer();
+  result.write(source);
+
+  while (result.length < length) {
+    result.write(' ');
+  }

[Bob Nystrom, 2014/12/11 20:25:31]

result.write(' ' * (length - result.length));

[nweiz, 2014/12/11 23:55:24]

Done.

+
+  return result.toString();
+}