Hello, I am a somewhat experienced programmer and a complete Haskell newbie, so I hope this is the correct ML for my question. I have decided to learn Haskell and started with Graham Hutton's book. Everything was going nicely until section 8.4, on sequencing functional parsers. I am trying to write an elementary parser that produces the 1st and 3d elements from a string. I am using the code from the book. --------------------- type Parser a = String -> [(a, String)] return :: a -> Parser a return v = \inp -> [(v, inp)] failure :: Parser a failure = \inp -> [] item :: Parser Char item = \inp -> case inp of [] -> [] (x:xs) -> [(x, xs)] parse :: Parser a -> String -> [(a, String)] parse p inp = p inp (>>=) :: Parser a -> (a -> Parser b) -> Parser b p >>= f = \inp -> case parse p inp of [] -> [] [(v, out)] -> parse (f v) out p :: Parser (Char, Char) p = do x <- item item y <- item return (x, y) -- LINE 34 -------------------- BUT, when I try to :load parse.hs from hugs I get the following error: ERROR "parse.hs":34 - Last generator in do {...} must be an expression I have no idea what I am doing wrong and why Hugs is complaining. I hope this question is not too simply for this mailing list, but I have honestly googled for an answer and had found nothing. Juozas Gaigalas