{----
 - Eval.hs - executable for evaluating a computation provide on stdin
 -           in the context of a module optionally provided on the
 -           command line.
 ----
 - 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
               []         -> ev 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
                   ev env
              Error err  -> error ("Uncaught Error\n" ++ show err)
              v        -> error $
                file ++ " compiled to something other than a module (bug)"

ev :: Env -> IO ()

ev e = do i <- getContents
          case (runp comp (startPos,()) i) of
               Success res _ _     ->
                 do v <- compute e res
                    case v of
                         Error err -> error $ show err
                         _         -> putStrLn $ show v
               Failure msg ((_,rel,line),_) ->
                error $ (show $
                            Error $ BadParse i line rel msg)