X-Git-Url: https://git.rmz.io/my-scheme.git/blobdiff_plain/1823a25e280d35093e3689ebb5a86361dd222504..7495ece1a44cd1a8cccae2bdbc61fa6873f106d2:/app/Main.hs?ds=inline diff --git a/app/Main.hs b/app/Main.hs index c0766c1..6daf522 100644 --- a/app/Main.hs +++ b/app/Main.hs @@ -1,7 +1,47 @@ module Main where +import Control.Monad +import Text.ParserCombinators.Parsec hiding (spaces) import System.Environment +data LispVal = Atom String + | List [LispVal] + | DottedList [LispVal] LispVal + | Number Integer + | String String + | Bool Bool + +symbol :: Parser Char +symbol = oneOf "!#$%&|*+-/:<=>?@^_~" + +spaces :: Parser () +spaces = skipMany space + +parseString :: Parser LispVal +parseString = do + char '"' + x <- many (noneOf "\"") + char '"' + return $ String x + +parseAtom :: Parser LispVal +parseAtom = do + a <- letter <|> symbol + b <- many (letter <|> digit <|> symbol) + let atom = a:b + return $ case atom of + "#t" -> Bool True + "#f" -> Bool False + _ -> Atom atom + +parseNumber :: Parser LispVal +parseNumber = liftM (Number . read) $ many1 digit + +readExpr :: String -> String +readExpr input = case parse (spaces >> symbol) "lisp" input of + Left err -> "No match: " ++ show err + Right val -> "Found value" + main :: IO () main = do - args <- getArgs - putStrLn ("Hello, " ++ args !! 0) + args <- getLine + putStrLn (readExpr args)