Overlapping flags and options or options with optional arguments

[ollef]

Hey, and thanks for an excellent library!

Is there any way to get a -v flag working on its own but also allow passing it an argument, such as -vn?

Many command-line utilities support this idiom (e.g. ghc), but I haven't been able to get it to work with optparse-applicative. I tried the following (and a few different variations):

option auto
    (long "verbose"
    <> short 'v'
    <> metavar "LEVEL"
    <> help "Set the verbosity level to LEVEL")
<|>
flag 0 1
    (long "verbose"
    <> short 'v'
    <> help "Enable verbose mode")

but it seems like the option takes precedence.

Cheers!

[HuwCampbell]

Cheers.
No, there isn't a way to do this by design, as this situation can lead to an ambiguous parse. Please see #194 for more of an explanation.

[ollef]

Alright, I guess I'll have to live with the argument form then.

Feel free to close the issue if it won't happen. Thanks for your reply!

Perhaps this should be documented?

[HuwCampbell]

I'm adding this to the README