如何在optparse-applicative中获得“剩余参数”？

Question

I am trying to use optparse-applicative. How can I access arguments that are not options? (From prog --foo --bar=42 baz , I want to get ["baz"] )

All the the "high level" functions https://hackage.haskell.org/package/optparse-applicative-0.11.0.2/docs/Options-Applicative-Extra.html return a where I want (a,[String]) .

There is some low-level function https://hackage.haskell.org/package/optparse-applicative-0.11.0.2/docs/Options-Applicative-Common.html#v:runParser but I cannot call it directly because of its type. And indeed I do want to re-use all the plumbing that is in https://hackage.haskell.org/package/optparse-applicative-0.11.0.2/docs/src/Options-Applicative-Extra.html#execParser .

Answer 1

Positional arguments are part of the parser specification. They are not returned separately by the function that runs the parser. The functions argument and strArgument can be used to add a parser for a positional argument to the specification.