type Parser = Parsec String () Source

type GenParser tok st = Parsec [tok] st Source

parseFromFile :: Parser a -> FilePath -> IO (Either ParseError a) Source

parseFromFile p filePath runs a string parser p on the input read from filePath using readFile. Returns either a ParseError (Left) or a value of type a (Right).

 main    = do{ result <- parseFromFile numbers "digits.txt"
             ; case result of
                 Left err  -> print err
                 Right xs  -> print (sum xs)
             }