0.9.0

Breaking

• Support for Swift < 4.2 has been removed.

Enhancements

• Added syntax for using array as a type with Argument instead of using VariadicArgument:

  command(Argument<[String]>("names")) { names in }

• Added support for optional arguments and options, for example:

  command(Argument<String?>("name")) { name in }
  command(Option<String?>("name", default: nil)) { name in }

• Added support for using -- to signal that subsequent values should be treated as arguments instead of options.
  Tamas Lustyik

• Output of --help for group commands will now sort the commands in alphabetical order.
  Cameron Mc Gorian

Bug Fixes

• Showing default values for custom ArgumentConvertible types are now supported in the --help output of commands.

• Only print errors in red if the output terminal supports ANSI colour codes.
  #58

• ArgumentParser.isEmpty will now return empty for empty arguments.