Hi,
I am also happy with the proposal. The only thing I could not figure out is
whether changing the COMPLETE sets to the new syntax works also in the old
one. I mean, would a way to ensure compatibility with both current GHC, and
GHC+this proposal to write:
{-# COMPLETE … :: Either l r #-}
Regards,
Alejandro
El 16 sept 2021 18:55:46, Joachim Breitner
Hi,
very convincing proposal, so I am happy with it.
I’ll ask a minor question about breaking existing COMPLETE pragmas on Github.
Cheers, Joachim
Am Donnerstag, dem 16.09.2021 um 19:07 +0300 schrieb Vladislav Zavialov (int-index):
Dear Committee,
Proposal #400 "COMPLETE set signatures” by Sebastian Graf has been submitted for our consideration.
Read it here: https://github.com/sgraf812/ghc-proposals/blob/constrained-complete-sigs/pro...
Discussion here: https://github.com/ghc-proposals/ghc-proposals/pull/400
The proposal presents an alternative treatment for type annotations on COMPLETE pragmas. Today one could write
{-# COMPLETE P, Q :: Either #-}
where P and Q are some pattern synonyms. But this isn’t even well-kinded.
Instead, the author proposes that we ask our users to write
{-# COMPLETE P, Q :: Either l r #-}
By requiring a proper type on the RHS, we also gain the ability to talk about more advanced use cases (described in the proposal).
I recommend acceptance. In fact, I learned about the way these annotations are treated today only from reading the proposal, and it came as a surprise to me. Using proper, well-kinded types there, seems like the right thing to do even if we ignore the new use cases it enables.
Let me know what you think.
- Vlad
_______________________________________________
ghc-steering-committee mailing list
ghc-steering-committee@haskell.org
https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee
-- Joachim Breitner mail@joachim-breitner.de http://www.joachim-breitner.de/
_______________________________________________ ghc-steering-committee mailing list ghc-steering-committee@haskell.org https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee