Kind classes and associated closed type families

Ryan Scott at
Tue Dec 22 01:43:13 UTC 2015

Running :kind! twice in a row does nothing, and your hunch was
correct: it does appear to be a bug. Specifically, it's a bug that
affects type families with polymorphic return kinds (like Extract,
which has kind y). I've opened Trac #11275 [1] for this issue.

Ryan S.

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