
Hi, Am Montag, den 09.09.2013, 15:57 +0000 schrieb Simon Peyton-Jones:
I think I'd prefer all of these checks to be done in checkValidInstHead. It makes sense... it's just the kind of thing that checkValidInstHead is for. It would remove clutter (and filtration) from tcInstDecls1.
The same goes for the SafeHaskell checks in tcInstDecls1.
I'm not sure who is willing to do this? If no one wants to do it now can someone make a ticket? But it might be easier just to cut to the chase and do it :-)
I tried to cut the chase, but the issue is that checkValidInstHead has no idea whether the instance head it is about to check is a standalone instance or a regular one. For Coercible this is fine, but for Typeable it needs to allow standalone instances. So this requires more refactoring than I’m comfortable to do at the moment, hence the requested ticket: http://ghc.haskell.org/trac/ghc/ticket/8264 Greetings, Joachim -- Joachim “nomeata” Breitner mail@joachim-breitner.de • http://www.joachim-breitner.de/ Jabber: nomeata@joachim-breitner.de • GPG-Key: 0x4743206C Debian Developer: nomeata@debian.org