X-Git-Url: https://git.rmz.io/my-scheme.git/blobdiff_plain/dbed09e123cb19f347a74e8c6fb6edf7e4931b5c..537e327f072fb094316845a5e3105f4fbb1aa385:/app/Main.hs diff --git a/app/Main.hs b/app/Main.hs index de1c1ab..88ae7f7 100644 --- a/app/Main.hs +++ b/app/Main.hs @@ -1,6 +1,54 @@ module Main where +import Control.Monad +import Text.ParserCombinators.Parsec hiding (spaces) +import System.Environment -import Lib +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 = many1 digit >>= \ ds -> + let a = read ds + in return $ Number a + +parseExpr :: Parser LispVal +parseExpr = parseString + <|> parseAtom + <|> parseNumber + +readExpr :: String -> String +readExpr input = case parse parseExpr "lisp" input of + Left err -> "No match: " ++ show err + Right val -> "Found value" main :: IO () -main = someFunc +main = do + args <- getLine + putStrLn (readExpr args)