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Diffstat (limited to 'compiler/GHC/Tc/Utils/Unify.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/Unify.hs | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/compiler/GHC/Tc/Utils/Unify.hs b/compiler/GHC/Tc/Utils/Unify.hs index f7e1ec938a..41faa2fece 100644 --- a/compiler/GHC/Tc/Utils/Unify.hs +++ b/compiler/GHC/Tc/Utils/Unify.hs @@ -2307,6 +2307,9 @@ Needless to say, all there are wrinkles: Note [TyVar/TyVar orientation] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +See also Note [Fundeps with instances, and equality orientation] +where the kind equality orientation is important + Given (a ~ b), should we orient the CEqCan as (a~b) or (b~a)? This is a surprisingly tricky question! This is invariant (TyEq:TV). |