This repository was archived by the owner on Jul 16, 2024. It is now read-only.
Make type families in Data.Row.Internal polykinded#20
Merged
dwincort merged 1 commit intotarget:masterfrom Apr 25, 2018
Merged
Conversation
Contributor
|
LGTM, @dwincort what say you? |
dwincort
approved these changes
Apr 25, 2018
Collaborator
dwincort
left a comment
dwincort
left a comment
There was a problem hiding this comment.
Thanks for putting in the work!
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
#19
The primary motivation is to be able to use
.==and.+to construct rows of kinds other than*.Examples.lhscompiles without any changes, however this change is potentially breaking becauseForallis now poly-kinded and thus previously working programs may require additional annotations to compile.The changes to the
Forallclass seem to be the sole reason whyData.Row.RecordandData.Row.Variantsneeded to be touched. At a high level it makes sense to me to make said class poly-kinded since we could have something likenewtype RecF (r :: Row (* -> *)) (a :: *),newtype VarF (r :: Row (* -> *)) (a :: *)for which we would be able to write instancesForall f Functor => Functor (RecF r),Forall f Functor => Functor (VarF r).I don't totally understand the type signatures though, so if I messed up anywhere it's probably there.