perga/app/Main.hs

module Main where

import Control.Monad (void)
import qualified Data.Map as M
import qualified Data.Text.IO as T
import Eval (Env)
import Parser
import Repl
import System.Environment
import System.IO

main :: IO ()
main = do
    args <- getArgs
    case args of
        [] -> void repl
        [file] -> handleFile file
        _ -> putStrLn "usage './perga' for repl and './perga <filename>' to get input from a file"

dumpEnv :: Env -> IO ()
dumpEnv = void . M.traverseWithKey ((putStrLn .) . showEnvEntry)

handleFile :: String -> IO ()
handleFile fileName =
    do
        fileH <- openFile fileName ReadMode
        input <- T.hGetContents fileH
        case parseProgram input of
            Left err -> putStrLn err
            Right env -> dumpEnv env