Docopt.hs - parsing command line options <=> matching a regexp

Docopt.hs

module Docopt where

import System.Environment (getArgs)

import Regexp

data DocoptResult = DocoptCommand Bool
                  | DocoptPositionalArg (Maybe String)
                  | DocoptRepatableArg [String]
                  | DocoptFlag Bool
                  | DocoptRepeatableFlag Int

data DocoptOption = DocoptOption {
  docoptOptionShort :: Maybe Char,
  docoptOptionLong  :: Maybe String
}

{-
Usage:
  test1.py <foo> [-k] bar
  test1.py <foo> [-l] baz
  test1.py [-h|-v]
  test1.py fubaz Z... to X...
  test1.py [-v|-vv|-vvv] xyzzy ZYXXY
-}

main :: IO ()
main = getArgs >>= print

testParams1a = ["fooFile", "bar"]
testParams1b = ["fooFile", "-k", "bar"]
testParams2a = ["fooFile", "baz"]
testParams2b = ["fooFile", "-l", "baz"]
testParams3a = ["fubaz", "1", "2", "to", "3", "4"]

usage :: Regexp String
usage = first ~|~ second ~|~ third ~|~ forth ~|~ fifth
  where first  = concatMany [anyChar, optional (character "-k"), character "bar"]
        second = concatMany [anyChar, optional (character "-l"), character "baz"]
        third  = character "-h" ~|~ character "-v"
        forth  = concatMany [character "fubaz", kleeneCross anyChar, character "to", kleeneCross anyChar]
        fifth  = concatMany [optional $ character "-v" ~|~ character "-vv" ~|~ character "-vvv", character "xyzzy", anyChar]