Ross, Amr, OK. I've done rebindable syntax for do-notation, in the HEAD. Care to try it? What this means is that, with -fno-implicit-prelude, do { pat <- e; Q } has the same static semantics as e >>= (\x -> case x of { pat -> do { Q }; other -> fail "urk") where the (>>=) is whatever (>>=) happens to be in scope at that point. The situation for arrows is unchanged; no rebindable syntax. (Partly because the detailed spec is unclear.) It does *not* work for mdo, because mdo uses (>>=) at a polymorphic type. Just do-notation. Which is, I hope, enough for you. Simon | -----Original Message----- | From: Amr A Sabry [mailto:sabry@cs.indiana.edu] | Sent: 24 January 2005 19:40 | To: Simon Peyton-Jones | Cc: Amr A Sabry; ross@soi.city.ac.uk | Subject: Re: Rebindable syntax for monads and arrows | | > You've convinced me about the monad one; GHC doesn't implement its own | > manual! And it's not hard to fix. So it's on my to-do list. | | :-) | | > Meanwhile, I'd like to know: if I did the monad thing, would that be | > useful to you, or just a generally good thing. And if the former, how | > useful? That is, how hard should I try to get to it?! | | It would definitely be useful but not critical at this point. | | Thanks. --Amr