Closed solomon-b closed 2 years ago
BTW, it would be nice to have tests for the sequenceA
laws, too. Feel free to add them, but there's no obligation. :)
I think it follows from Identity and Composition so we are okay without it.
Do you know a proof?
hmm, i actually haven't been able to find a proof, but this link claims it is guaranteed to hold: https://en.wikibooks.org/wiki/Haskell/Traversable#The_Traversable_laws
Great!
Regarding naturality, note this change: https://gitlab.haskell.org/ghc/ghc/-/merge_requests/7492
Well there you go. Should we hold off on merging this until a working implementation is produced?
Well there you go. Should we hold off on merging this until a working implementation is produced?
When do you expect it to land?
IMHO the existing changes are good additions which shouldn't be held back for very long.
Well there you go. Should we hold off on merging this until a working implementation is produced?
When do you expect it to land?
IMHO the existing changes are good additions which shouldn't be held back for very long.
To be honest, I'm a little stumped on this how to fix it. Is there anyone with more quickcheck experience who we can ask? The issue is the rank2 type.
Published in v0.6.0: https://hackage.haskell.org/package/checkers-0.6.0
Resolves issue #24
I wasn't able to implement the Naturality test correctly, but I left it in as a comment in case someone else can get it working. I think it follows from Identity and Composition so we are okay without it.