X-Git-Url: https://git.rmz.io/my-scheme.git/blobdiff_plain/0a6833657330f8514c235e672b1d4dc6e1ec7ad5..369fde6e9fc7f5ddd28d83e34da21624cb4c2c7c:/app/Main.hs diff --git a/app/Main.hs b/app/Main.hs index cea4c9b..c71126b 100644 --- a/app/Main.hs +++ b/app/Main.hs @@ -2,6 +2,7 @@ module Main where import Control.Monad import Text.ParserCombinators.Parsec hiding (spaces) import System.Environment +import Numeric data LispVal = Atom String | List [LispVal] @@ -22,7 +23,16 @@ parseString = do char '"' x <- many innerChar char '"' return $ String x - where innerChar = noneOf "\"" + where innerChar = noneOf ['\\', '\"'] <|> escapeChar + escapeChar = do char '\\' + c <- oneOf ['\"', '\\', 'n', 'r', 't', 'f'] + return $ case c of + '\"' -> '\"' + '\\' -> '\\' + 'n' -> '\n' + 'r' -> '\r' + 't' -> '\t' + 'f' -> '\f' parseAtom :: Parser LispVal parseAtom = do @@ -35,14 +45,21 @@ parseAtom = do _ -> Atom atom parseNumber :: Parser LispVal -parseNumber = do ds <- many1 digit - let a = read ds +parseNumber = do toNum <- radix + ds <- many1 digit + let ((a,_):_) = toNum ds return $ Number a + where radix = do r <- try (char '#' >> oneOf "bodx") <|> return 'd' + return $ case r of + 'd' -> readDec + 'x' -> readHex + 'o' -> readOct + 'b' -> readInt 2 (\x -> elem x "01") (read . (:[])) parseExpr :: Parser LispVal parseExpr = parseString - <|> parseAtom <|> parseNumber + <|> parseAtom readExpr :: String -> String readExpr input = case parse parseExpr "lisp" input of