{----
 - Repl.hs - the noodle read-eval-print-loop
 ----
 - Author: Jesse Rudolph <jesse.rudolph@gmail.com>
 - See LICENSE for licensing details
 ----------------------------------------------------------------- -}

module Main (
    main
) where

import System.Environment
import Data.List
import System.IO

import qualified Language.Noodle.Banner as Banner
import Language.Noodle.DepTree
import Language.Noodle.Evaluation
import Language.Noodle.Lib.Basic
import Language.Noodle.Syntax
import Language.Noodle.Parsing.String
import Language.Noodle.Parsing.Noodle


main = do args <- getArgs
          case args of
               []         -> repl env
               [filepath] -> exec filepath
               _          -> error "invalid command line arguments"
-- execute a source file
exec :: FilePath -> IO ()
exec file
    = do val <- compileFile env file
         case val of
              Module e ->
                do env <- e
                   repl env
              Error err  -> error ("Uncaught Error\n" ++ show err)
              v        -> error $
                file ++ " compiled to something other than a module (bug)"

repl :: Env -> IO ()

repl e = do putStr "noodle> "
            hFlush stdout
            i <- getLine
            case (runp comp (startPos,()) i) of
                 Success res _ _     ->
                   do v <- compute e res
                      putStrLn $ " ==>" ++ show v
                 Failure msg ((_,rel,line),_) ->
                  putStrLn $ (show $
                              Error $ BadParse i line rel msg)
            putStr "\n"
            repl e