Handle boolean constants

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

diff --git a/app/Main.hs b/app/Main.hs
index 2740935ca44f24d9121b6d9464c61c4b633b8121..6fcf6675f175374d22b749097dc06142312b8400 100644 (file)
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,8 +1,43 @@
 module Main where
 module Main where

-import Text.ParserCombinators.Parsec
+import Text.ParserCombinators.Parsec hiding (spaces)

 import System.Environment
 
 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
+
+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 <- getLine
 main :: IO ()
 main = do
     args <- getLine

-    putStrLn (args)
+    putStrLn (readExpr args)