diff options
Diffstat (limited to 'compiler/GHC/Tc/Solver/Interact.hs')
| -rw-r--r-- | compiler/GHC/Tc/Solver/Interact.hs | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/compiler/GHC/Tc/Solver/Interact.hs b/compiler/GHC/Tc/Solver/Interact.hs index 139bb3b6b8..f17b520c94 100644 --- a/compiler/GHC/Tc/Solver/Interact.hs +++ b/compiler/GHC/Tc/Solver/Interact.hs @@ -1391,7 +1391,7 @@ We generate these Wanteds in three places, depending on how we notice the injectivity. 1. When we have a [W] F tys1 ~ F tys2. This is handled in canEqCanLHS2, and -described in Note [Decomposing equality] in GHC.Tc.Solver.Canonical. +described in Note [Decomposing type family applications] in GHC.Tc.Solver.Canonical. 2. When we have [W] F tys1 ~ T and [W] F tys2 ~ T. Note that neither of these constraints rewrites the other, as they have different LHSs. This is done @@ -2283,11 +2283,9 @@ matchClassInst dflags inerts clas tys loc -- See Note [Instance and Given overlap] | not (xopt LangExt.IncoherentInstances dflags) , not (naturallyCoherentClass clas) - , let matchable_givens = matchableGivens loc pred inerts - , not (isEmptyBag matchable_givens) + , not (noMatchableGivenDicts inerts loc clas tys) = do { traceTcS "Delaying instance application" $ - vcat [ text "Work item=" <+> pprClassPred clas tys - , text "Potential matching givens:" <+> ppr matchable_givens ] + vcat [ text "Work item=" <+> pprClassPred clas tys ] ; return NotSure } | otherwise |