module Main where

import System.Console.Haskeline
import Text.Megaparsec.Error (errorBundlePretty)
import HW3.Parser (parse)
import HW3.Pretty (prettyValue)
import HW3.Evaluator (eval)

main :: IO ()
main = runInputT defaultSettings loop
  where
    loop :: InputT IO ()
    loop = do
      minput <- getInputLine "hi> "
      case minput of
        Nothing -> return ()
        Just "exit" -> return ()
        Just "quit" -> return ()
        Just "q" -> return ()
        Just input -> do
          case parse input of
            Left err -> outputStrLn $ errorBundlePretty err
            Right expr -> do
              mval <- eval expr
              case mval of
                Left err -> outputStrLn $ show err
                Right val -> outputStrLn $ show $ prettyValue val
          loop