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module Main where
import Control.Monad (liftM)
import Control.Monad.Except (throwError)
import Error (LispError (..), LispResult (..),
unwrap)
import Evaluator (eval)
import Parser (Expr (..), parseLispValue)
import System.Console.Readline
import System.Environment (getArgs)
import Text.ParserCombinators.Parsec
readExpr :: String -> LispResult Expr
readExpr inp =
case parse parseLispValue "(unknown)" inp of
Left err -> throwError $ Parse err
Right val -> return val
repl :: IO ()
repl = do
inp <- readline "(lisk)> "
case inp of
Nothing -> return ()
Just ",q" -> return ()
Just line -> do
addHistory line
-- TODO: don't directly print Either values
print $ eval =<< readExpr line
repl
main :: IO ()
main = do
args <- getArgs
if null args
then do
putStrLn ";;; Entering lisk repl ..."
repl
else print $ eval =<< readExpr (head args)
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