"arguments" swallows options

[dag]

If "arguments" isn't the last argument in the applicative declaration it swallows all options (including --hyphenated ones etc). I'm not sure whether this is a bug or a limitation of applicative?

I suppose a work around if you don't want to reorder your data structure is to use some helper function instead of applying your data constructor directly. But if this isn't about a limitation of applicative it would be nice to need no such workarounds! :)

[pcapriotti]

There a few ways to work around this:

• Use the new arrow interface (in 0.1.1) to move the arguments parser to the
  end, regardless of the position of the corresponding field in the parsed
  record.

• Pass a custom reader to arguments that ignores things that look like
  arguments. For example:

  str' :: String -> Maybe String
  str' ('-':_) = Nothing
  str' x = Just x

This should really be integrated into arguments, however.

[dag]

It's also common to have -- mark "end of flags", so could be nice if arguments supported that convention as well. That is, -- --hyphenated still parses into ["--hyphenated"].

[pcapriotti]

Yes, that should be supported as well.

At the moment, you can emulate it by adding a subparser with a single command "--" returning the same argument parser, but it's a bit of a hack, and you get a weird -- in the help page, which is not ideal.