I am getting frustrated when trying to implement a parser for a minimal TeX subset. I am essentially trying to implement something that recognizes \commands (no parameters yet), paragraphs (two newlines), and text (almost anything else). The code I have so far is: module UnTeX where import Text.ParserCombinators.Parsec import Text.ParserCombinators.Parsec.Prim import Text.ParserCombinators.Parsec.Language import qualified Text.ParserCombinators.Parsec.Token as T data UnTeX = Command String | Text String | Paragraph deriving Show command :: Parser UnTeX command = do char '\\' cmd <- many1 (letter <|> digit) "command" return $ Command cmd paragraph :: Parser UnTeX paragraph = do newline newline return $ Paragraph text :: Parser UnTeX text = do txt <- many1 (alphaNum <|> space) return $ Text txt I have no illusions that this is probably far from what I actually need to be doing. But I am finding documentation on all this to be spotty. The 'parsec.pdf' is 7 years old and code doesn't always work. Can anyone point me in the right direction? I just want something to able to do this simply. After an initial version works, I would like to have commands with parameters - something like \command[param][param]{body} but need to have something working first. Thank you for any help you can provide. Jeffrey.