Add basic support for a configuration file.

lib/src/utils.dart

 // Copyright (c) 2013, 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.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:math' as math;
 
 import 'package:async/async.dart' hide StreamQueue;
 import 'package:crypto/crypto.dart';
@@ skipping 16 matching lines @@
 /// A typedef for a zero-argument callback function.
 typedef void Callback();
 
 /// A converter that decodes bytes using UTF-8 and splits them on newlines.
 final lineSplitter = UTF8.decoder.fuse(const LineSplitter());
 
 /// A regular expression to match the exception prefix that some exceptions'
 /// [Object.toString] values contain.
 final _exceptionPrefix = new RegExp(r'^([A-Z][a-zA-Z]*)?(Exception|Error): ');
 
+/// A regular expression matching a single vowel.
+final _vowel = new RegExp('[aeiou]');
+
 /// Directories that are specific to OS X.
 ///
 /// This is used to try to distinguish OS X and Linux in [currentOSGuess].
 final _macOSDirectories = new Set<String>.from([
   "/Applications",
   "/Library",
   "/Network",
   "/System",
   "/Users"
 ]);
@@ skipping 64 matching lines @@
 /// Returns [name] if [number] is 1, or the plural of [name] otherwise.
 ///
 /// By default, this just adds "s" to the end of [name] to get the plural. If
 /// [plural] is passed, that's used instead.
 String pluralize(String name, int number, {String plural}) {
   if (number == 1) return name;
   if (plural != null) return plural;
   return '${name}s';
 }
 
+/// Returns [noun] with an indefinite article ("a" or "an") added, based on
+/// whether its first letter is a vowel.
+String a(String noun) => noun.startsWith(_vowel) ? "an $noun" : "a $noun";
+
 /// Wraps [text] so that it fits within [lineLength], which defaults to 100
 /// characters.
 ///
 /// This preserves existing newlines and doesn't consider terminal color escapes
 /// part of a word's length.
 String wordWrap(String text, {int lineLength}) {
   if (lineLength == null) lineLength = _lineLength;
   return text.split("\n").map((originalLine) {
     var buffer = new StringBuffer();
     var lengthSoFar = 0;
@@ skipping 278 matching lines @@
       urlSafe: urlSafe, addLineSeparator: addLineSeparator);
 }
 
 /// Returns middleware that nests all requests beneath the URL prefix [beneath].
 shelf.Middleware nestingMiddleware(String beneath) {
   return (handler) {
     var pathHandler = new PathHandler()..add(beneath, handler);
     return pathHandler.handler;
   };
 }