{-# LANGUAGE OverloadedStrings #-}

-- | Accepting arguments to be passed through to a sub-process.

module Options.Applicative.Args

(argsArgument

,argsOption

,cmdOption

,parseArgsFromString)

where

import Data.Attoparsec.Args

import qualified Data.Attoparsec.Text as P

import qualified Data.Text as T

import qualified Options.Applicative as O

-- | An argument which accepts a list of arguments e.g. @--ghc-options="-X P.hs \"this\""@.

argsArgument :: O.Mod O.ArgumentFields [String] -> O.Parser [String]

argsArgument =

O.argument

(do string <- O.str

either O.readerError return (parseArgsFromString string))

-- | An option which accepts a list of arguments e.g. @--ghc-options="-X P.hs \"this\""@.

argsOption :: O.Mod O.OptionFields [String] -> O.Parser [String]

argsOption =

O.option

(do string <- O.str

either O.readerError return (parseArgsFromString string))

-- | An option which accepts a command and a list of arguments e.g. @--exec "echo hello world"@

cmdOption :: O.Mod O.OptionFields (String, [String]) -> O.Parser (String, [String])

cmdOption =

O.option

(do string <- O.str

xs <- either O.readerError return (parseArgsFromString string)

case xs of

[] -> O.readerError "Must provide a command"

x:xs' -> return (x, xs'))

-- | Parse from a string.

parseArgsFromString :: String -> Either String [String]

parseArgsFromString = P.parseOnly (argsParser Escaping) . T.pack