pkg/args: expose immutable collections

pkg/args/lib/src/parser.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.
 
 library args.src.parser;
 
 import '../args.dart';
 
 final _SOLO_OPT = new RegExp(r'^-([a-zA-Z0-9])$');
 final _ABBR_OPT = new RegExp(r'^-([a-zA-Z0-9]+)(.*)$');
@@ skipping 23 matching lines @@
   /** The grammar being parsed. */
   final ArgParser grammar;
 
   /** The arguments being parsed. */
   final List<String> args;
 
   /** The remaining non-option, non-command arguments. */
   final rest = <String>[];
 
   /** The accumulated parsed options. */
-  final Map results = {};
+  final Map<String, dynamic> results = <String, dynamic>{};
 
   Parser(this.commandName, this.grammar, this.args, this.parent, rest,
       {this.allowTrailingOptions: false}) {
     if (rest != null) this.rest.addAll(rest);
   }
 
 
   /** The current argument being parsed. */
   String get current => args[0];
 
@@ skipping 215 matching lines @@
       return parent.parseLongOption();
     }
 
     return true;
   }
 
   /**
    * Called during parsing to validate the arguments. Throws a
    * [FormatException] if [condition] is `false`.
    */
-  validate(bool condition, String message) {
+  void validate(bool condition, String message) {
     if (!condition) throw new FormatException(message);
   }
 
   /** Validates and stores [value] as the value for [option]. */
-  setOption(Map results, Option option, value) {
+  void setOption(Map results, Option option, value) {
     // See if it's one of the allowed values.
     if (option.allowed != null) {
       validate(option.allowed.any((allow) => allow == value),
           '"$value" is not an allowed value for option "${option.name}".');
     }
 
     if (option.allowMultiple) {
       results[option.name].add(value);
     } else {
       results[option.name] = value;
     }
   }
 }