Support #bodx in number parser

[my-scheme.git] / app / Main.hs

diff --git a/app/Main.hs b/app/Main.hs
index de1c1ab35c4ad21e14ec824121b9710418b75c39..c71126b500c4a581a4e6d2bf61577352bd89cd1b 100644 (file)
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,6 +1,73 @@
 module Main where
 module Main where

+import Control.Monad
+import Text.ParserCombinators.Parsec hiding (spaces)
+import System.Environment
+import Numeric

 
 

-import Lib
+data LispVal = Atom String
+             | List [LispVal]
+             | DottedList [LispVal] LispVal
+             | Number Integer
+             | String String
+             | Bool Bool
+             deriving Show
+
+symbol :: Parser Char
+symbol = oneOf "!#$%&|*+-/:<=>?@^_~"
+
+spaces :: Parser ()
+spaces = skipMany space
+
+parseString :: Parser LispVal
+parseString = do char '"'
+                 x <- many innerChar
+                 char '"'
+                 return $ String x
+              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
+    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 = 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
+        <|> parseNumber
+        <|> parseAtom
+
+readExpr :: String -> String
+readExpr input = case parse parseExpr "lisp" input of
+    Left err -> "No match: " ++ show err
+    Right val -> "Found value: " ++ show val

 
 main :: IO ()
 
 main :: IO ()

-main = someFunc
+main = do
+    args <- getLine
+    putStrLn (readExpr args)
+    main