A thin layer over optparse-applicative that avoids type plumbing for subcommands by using Parser (IO ()).
Various wrapper functions are also provided for common option/arg idioms.
See the library's documentation for details of all the functions provided.
$ cat readme.hsimport SimpleCmdArgs import Control.Applicative (some) import System.Directory main = simpleCmdArgs Nothing "readme example" "Longer description..." $ subcommands [ Subcommand "echo" "Print words" $ putStrLn . unwords <$> some (strArg "STR...") , Subcommand "ls" "List directory" $ ls <$> strArg "DIR" , Subcommand "mkdir" "Create directory" $ mkdir <$> parentsOpt <*> strArg "DIR" ] where parentsOpt = switchWith 'p' "parents" "Make missing directories" ls :: FilePath -> IO () ls dir = listDirectory dir >>= mapM_ putStrLn mkdir :: Bool -> FilePath -> IO () mkdir parents = if parents then createDirectoryIfMissing True else createDirectory$ ghc readme.hs $ ./readme --help readme example Usage: readme COMMAND Longer description... Available options: -h,--help Show this help text Available commands: echo Print words ls List directory mkdir Create directory $ ./readme echo hello world hello world $ ./readme mkdir -h Usage: readme mkdir [-p|--parents] DIR Create directory Available options: -p,--parents Make missing directories -h,--help Show this help textSee the examples.
Hackage packages using this library: https://packdeps.haskellers.com/reverse/simple-cmd-args