Use int/double auto-parsing and allowed values

[seaneagan]

Note: I didn't test this, and didn't update README, but here's some other stuff unscripted provides that you can take advantage of:

Type annotating parameters with types that have a static parse method will automatically use that to validate and parse the argument, and display an error and help text if an invalid value was passed. So in this case int.parse and double.parse will be used.

allowed specifies the allowed values of an option, which will also display an error on an invalid value, and will show up in the help. Can pass a List or a Map from values to help text for each value.

Either type annotating an option as a List, or specifying allowMultiple will mean you can specify option multiple times on the command line, and they will be passed to the function as a List. I filed a bug for unscripted to support comma separated values:

seaneagan/unscripted#49

[alexgann]

@seaneagan - thanks so much! I had originally tried with int/double but get the following error whenever I try:

Unhandled exception:
Class '_LocalClassMirror' has no instance method '[]'.

NoSuchMethodError: method not found: '[]'
Receiver: Instance of '_LocalClassMirror'
Arguments: [Instance of 'Symbol']
#0      Object.noSuchMethod (dart:core-patch/object_patch.dart:45)
#1      getParserFromType (package:unscripted/src/util.dart:172:29)
#2      getUsageFromFunction.<anonymous closure> (package:unscripted/src/util.dart:131:33)
#3      IterableBase.forEach (dart:collection/iterable.dart:222)
#4      getUsageFromFunction (package:unscripted/src/util.dart:111:61)
#5      DeclarationScript.usage (package:unscripted/src/script_impl.dart:69:42)
#6      ScriptImpl.execute (package:unscripted/src/script_impl.dart:27:55)
#7      main (file:///C:/Users/agann/GitHub/SoundDart/bin/sounddart.dart:12:56)
#8      _startIsolate.isolateStartHandler (dart:isolate-patch/isolate_patch.dart:216)
#9      _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:116)

[seaneagan]

Ah, they removed a feature from dart:mirrors that I was using. Fixed in unscripted 0.3.2:

http://pub.dartlang.org/packages/unscripted

Thanks!