lambda/app/Main.hs

module Main (main) where

import System.IO
import Parser (pAll)
import Lambda (betaReduce, Term)

interaction :: Term -> IO ()
interaction t = do
    print t
    putStr "? "
    hFlush stdout
    input <- getLine
    if input == "q" then
        pure ()
    else 
        interaction (betaReduce t)

repl :: IO ()
repl = do
    putStr "> "
    hFlush stdout
    input <- getLine
    case pAll input of
        Left err -> putStrLn ("\n" ++ "ERROR: " ++ err) >> repl
        Right t -> interaction t >> repl

main :: IO ()
main = repl