temp backup

interp :: Code -> Code -> Conf -> IO Conf
interp _ [] final_state = return final_state
interp before after@(JUMP shft : rest) state =
    let pc = JUMP shft in
    if shft > 0
    then do -- jump forwards
        let (skipped, interpNext) = splitAt shft after
        let reversed = reverse skipped
        interp (reversed ++ before) interpNext state
    else do -- jump backwards
        let shft = abs shft
        let (skipped, new_before) = splitAt shft before
        let reversed = reverse skipped
        interp new_before (reversed ++ after) state
interp before after@(JMPZ shft : rest) state = undefined
interp before after state = do
    let new_state = interpJustOne (head after) state
    new_state' <- new_state
    interp (head after : before) (tail after) new_state'

performJump :: [Instr] -> [Instr] -> Conf -> IO Conf
performJump before after@(JUMP shft : rest) state =
    let pc = JUMP shft in
    if shft > 0
    then do -- jump forwards
        let (skipped, interpNext) = splitAt shft after
        let reversed = reverse skipped
        interp (reversed ++ before) interpNext state
    else do -- jump backwards
        let shft = abs shft
        let (skipped, new_before) = splitAt shft before
        let reversed = reverse skipped
        interp new_before (reversed ++ after) state