Parse comma-separated multiple values.

README.md

 Parses raw command-line arguments into a set of options and values.
 
 This library supports [GNU][] and [POSIX][] style options, and it works
 in both server-side and client-side apps.
 
 ## Defining options
 
 First create an [ArgParser][]:
 
     var parser = new ArgParser();
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 option can occur multiple times, and the `parse()` method returns a list of
 values:
 
 ```dart
 var parser = new ArgParser();
 parser.addOption('mode', allowMultiple: true);
 var results = parser.parse(['--mode', 'on', '--mode', 'off']);
 print(results['mode']); // prints '[on, off]'
 ```
 
+By default, values for a multi-valued option may also be separated with commas:
+
+```dart
+var parser = new ArgParser();
+parser.addOption('mode', allowMultiple: true);
+var results = parser.parse(['--mode', 'on,off']);
+print(results['mode']); // prints '[on, off]'
+```
+
+This can be disabled by passing `splitCommas: false`.
+
 ## Defining commands ##
 
 In addition to *options*, you can also define *commands*. A command is a named
 argument that has its own set of options. For example, consider this shell
 command:
 
 ```
 $ git commit -a
 ```
 
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 [Command]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.Command
 [UsageError]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.UsageError
 [addOption]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.ArgParser@id_addOption
 [addFlag]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.ArgParser@id_addFlag
 [parse]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.ArgParser@id_parse
 [rest]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.ArgResults@id_rest
 [addCommand]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.ArgParser@id_addCommand
 [getUsage]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.ArgParser@id_getUsage
 [addSubcommand]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.Command@id_addSubcommand
 [run]: http://www.dartdocs.org/documentation/args/latest/index.html#args/args.Command@id_run