diff options
| author | Richard Eisenberg <rae@richarde.dev> | 2021-01-05 22:40:53 -0500 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-01-23 15:29:58 -0500 |
| commit | 8fd855f09db0090df74a2e35eace7da973f62c86 (patch) | |
| tree | d40af8ffa28d1b05411869aa1a972091d3eca07c /compiler/GHC/Core/FamInstEnv.hs | |
| parent | 420ef55a0d28a177fab981655a1c44291b441382 (diff) | |
| download | haskell-8fd855f09db0090df74a2e35eace7da973f62c86.tar.gz | |
Make matchableGivens more reliably correct.
This has two fixes:
1. Take TyVarTvs into account in matchableGivens. This
fixes #19106.
2. Don't allow unifying alpha ~ Maybe alpha. This fixes
#19107.
This patch also removes a redundant Note and redirects
references to a better replacement.
Also some refactoring/improvements around the BindFun
in the pure unifier, which now can take the RHS type
into account.
Close #19106.
Close #19107.
Test case: partial-sigs/should_compile/T19106,
typecheck/should_compile/T19107
Diffstat (limited to 'compiler/GHC/Core/FamInstEnv.hs')
| -rw-r--r-- | compiler/GHC/Core/FamInstEnv.hs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/GHC/Core/FamInstEnv.hs b/compiler/GHC/Core/FamInstEnv.hs index 0876cacf57..3e0fc7361d 100644 --- a/compiler/GHC/Core/FamInstEnv.hs +++ b/compiler/GHC/Core/FamInstEnv.hs @@ -522,7 +522,7 @@ compatibleBranches (CoAxBranch { cab_lhs = lhs1, cab_rhs = rhs1 }) (CoAxBranch { cab_lhs = lhs2, cab_rhs = rhs2 }) = let (commonlhs1, commonlhs2) = zipAndUnzip lhs1 lhs2 -- See Note [Compatibility of eta-reduced axioms] - in case tcUnifyTysFG (const BindMe) commonlhs1 commonlhs2 of + in case tcUnifyTysFG alwaysBindFun commonlhs1 commonlhs2 of SurelyApart -> True Unifiable subst | Type.substTyAddInScope subst rhs1 `eqType` @@ -1204,7 +1204,7 @@ apartnessCheck :: [Type] -> Bool -- ^ True <=> equation can fire apartnessCheck flattened_target (CoAxBranch { cab_incomps = incomps }) = all (isSurelyApart - . tcUnifyTysFG (const BindMe) flattened_target + . tcUnifyTysFG alwaysBindFun flattened_target . coAxBranchLHS) incomps where isSurelyApart SurelyApart = True |