Parsec (parser combinator)

I think this is quite cool. (Parsing an IRC 'NICK foo' message)

special = oneOf "-[]\\`^{}_" -- Taken from RFC1459, except '_',
                             -- which I added (generally accepted character (are there others?)).

nick = do { string "NICK"; space;
            first <- letter; rest <- many1 $ alphaNum <|> special; eof;
            return $ Nick (first:rest) }

Not quite sure what I think of it in comparison to regular expressions, yet.

>>26-27
Indeed. In messages. mIRC sort of supports it, last I checked. And XChat seems to support it pretty well. As does Irssi. (Haven't tried other clients.)

>>28
I thought this, but you might potentially fuck up IRC clients that follow the spec strictly. So I think the best course of action is to follow the spec initially, and then investigate extensions later on (after I have a stable IRC server on the go). What do you think?