I don't have a specific application that's crying out for this, but I sometimes shy away from using higher-rank polymorphism because of the extra effort it can require. A possibly related question is whether you would expect to make record selectors and updaters work for all record types at the same time? That would definitely be very useful. -----Original Message----- From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf Of Simon Peyton-Jones Sent: 10 September 2008 15:25 To: Wolfgang Jeltsch; glasgow-haskell-users@haskell.org Cc: Dimitrios Vytiniotis (t-dimitv@microsoft.com) Subject: RE: Is FPH implemented in GHC? Not yet. But Dimitrios has just started a postdoc at MSR, so we will be working on fixing, once and for all, the impredicative story in GHC. Meanwhile, why do you ask? Making impredicative polymorphism work seems to be the Right Thing, but it's something of a "technology push", perhpas a solution in search of a problem. Do you have an application that needs it? This is a general question to GHC users. (If you don't know what impredicative polymorphism is, think "can I have a type like (Maybe (forall a. [a] -> [a]))".) Simon | -----Original Message----- | From: glasgow-haskell-users-bounces@haskell.org | [mailto:glasgow-haskell-users- bounces@haskell.org] On Behalf Of | Wolfgang Jeltsch | Sent: 10 September 2008 15:21 | To: glasgow-haskell-users@haskell.org | Subject: Is FPH implemented in GHC? | | Hello, | | is FPH implemented in GHC? If yes, will it be part of GHC 6.10.1? | | Best wishes, | Wolfgang | _______________________________________________ | Glasgow-haskell-users mailing list | Glasgow-haskell-users@haskell.org | http://www.haskell.org/mailman/listinfo/glasgow-haskell-users _______________________________________________ Glasgow-haskell-users mailing list Glasgow-haskell-users@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-users ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================