CommandLine.hs

{-# OPTIONS_GHC -fglasgow-exts #-}

module System.Console.CommandLine where

import System.Console.Haskeline
import Control.Monad.Trans (lift, MonadTrans)
import Control.Monad.State 
import Control.Applicative 
import qualified Data.Map as Map

type Callback  m a =  [String] -> CommandLineT m a
type CallbackList m a = Map.Map String (Callback m a)
type Environment = Map.Map String String

data CommandState m a = CS { registry  :: Environment
                           , callbacks :: CallbackList m a
                           }

newtype CommandLineT m a = CommandLineT (StateT (CommandState m a) (InputT m) a)
    deriving(Monad)

    
runCommandLine :: (MonadException m) => CommandLineT m a -> CommandState m  a -> m a
runCommandLine (CommandLineT x) cState = 
    runInputT defaultSettings (evalStateT x cState)