Warn when an unsupported platform is passed.

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 85 matching lines @@
 String getErrorMessage(error) =>
   error.toString().replaceFirst(_exceptionPrefix, '');
 
 /// Indent each line in [str] by two spaces.
 String indent(String str) =>
     str.replaceAll(new RegExp("^", multiLine: true), "  ");
 
 /// Returns a sentence fragment listing the elements of [iter].
 ///
 /// This converts each element of [iter] to a string and separates them with
-/// commas and/or "and" where appropriate.
-String toSentence(Iterable iter) {
+/// commas and/or [conjunction] where appropriate. The [conjunction] defaults to
+/// "and".
+String toSentence(Iterable iter, {String conjunction}) {
   if (iter.length == 1) return iter.first.toString();
+
   var result = iter.take(iter.length - 1).join(", ");
   if (iter.length > 2) result += ",";
-  return "$result and ${iter.last}";
+  return "$result ${conjunction ?? 'and'} ${iter.last}";
 }
 
 /// 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';
@@ skipping 315 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;
   };
 }