Add LispVal data type which can hold any Lisp value

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

diff --git a/app/Main.hs b/app/Main.hs
index 16e49391cac7ef3f27a6cf3c0abffab9d0fe3794..c64fd18d83b0cdf0575889388df8cfa6344619c8 100644 (file)
--- a/app/Main.hs
+++ b/app/Main.hs
@@ -1,7 +1,26 @@
 module Main where
+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
+
+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 (show (read (args !! 0) + read (args !! 1)))
+    args <- getLine
+    putStrLn (readExpr args)