[allow underscore in numeric literals
John Meacham <john@repetae.net>**20061026011232] hunk ./FrontEnd/Lexer.hs 367
-	ds <- lexWhile isDigit
-	rest <- getInput
+        let ld ds' = do
+                ds <- lexWhile isDigit
+                rest <- getInput
+                case rest of
+                    ('_':_) -> discard 1 >> ld (ds' ++ ds)
+                    rest -> return (ds' ++ ds,rest)
+        (ds,rest) <- ld []