I'm happy to be overruled on this, but I vote against this change for GHC 8. Personally, I like to have a policy of "no TH changes after the first RC". This gives ample time for TH clients to update their code. Iavor's suggestion would likely involve a new part of the InstanceD constructor, which would affect anyone constructing or matching on this constructor. If the change involved, say, only adding new functionality without changing anything existing, I would be more willing to include for GHC 8.
And, yes, I agree with Austin. Richard On Apr 14, 2016, at 2:17 PM, Austin Seipp <[email protected]> wrote: > Here's a question, on top of this one: why don't we require > template-haskell changes for most corresponding syntax changes? We > tend to play catch up with template-haskell sometimes and it's > relatively strange. I mean, in some sense, we could have said a while > back "This needs another revision, please add template haskell > support" and avoided it all. > > Richard has a better insight into this than I do, I'm sure, but it > seems - to me, anyway - like template-haskell support is a reasonable > bar for most surface-level syntax change to cross, before getting > merged. > > My intuition tells me that, most of the time, a lot of us simply > forget to make the changes, or ask for them in reviews, and so it > goes. > > On Thu, Apr 14, 2016 at 1:12 PM, Ben Gamari <[email protected]> wrote: >> Iavor Diatchki <[email protected]> writes: >> >>> Hello, >>> >>> Now that "OVERLAPPING" and "OVERLAPPABLE" are pragmas on the instances, do >>> we have a way to generate instances with such pragmas using Template >>> Haskell? I can't seem to find a way to do this, which is unfortunate. >>> >>> If I am not missing anything, would there be objections to adding it to the >>> TH library before the next release---I would volunteer to do the change >>> ASAP. >>> >> Indeed this is an unfortunate gap. Given that this shouldn't be a >> terribly invasive change I would be alright with this if Richard approves. >> >> Cheers, >> >> - Ben >> >> >> _______________________________________________ >> Libraries mailing list >> [email protected] >> http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries >> > > > > -- > Regards, > > Austin Seipp, Haskell Consultant > Well-Typed LLP, http://www.well-typed.com/ _______________________________________________ ghc-devs mailing list [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
