diff options
| author | Richard Eisenberg <rae@richarde.dev> | 2021-01-05 22:40:53 -0500 |
|---|---|---|
| committer | Richard Eisenberg <rae@richarde.dev> | 2021-01-15 23:14:13 -0500 |
| commit | 7d550ff71ee06c681756f60fbd3731559484afa3 (patch) | |
| tree | eab8a083e327c06272f1c95833174ecf347bea45 /compiler/GHC/Tc/Validity.hs | |
| parent | 0dba78410887ffc3d219639081e284ef7b67560a (diff) | |
| download | haskell-wip/T19106.tar.gz | |
Make matchableGivens more reliably correct.wip/T19106
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/Tc/Validity.hs')
| -rw-r--r-- | compiler/GHC/Tc/Validity.hs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/GHC/Tc/Validity.hs b/compiler/GHC/Tc/Validity.hs index ff6a89d02f..7a83bfc573 100644 --- a/compiler/GHC/Tc/Validity.hs +++ b/compiler/GHC/Tc/Validity.hs @@ -2452,8 +2452,8 @@ checkConsistentFamInst (InClsInst { ai_class = clas -- The /scoped/ type variables from the class-instance header -- should not be alpha-renamed. Inferred ones can be. no_bind_set = mkVarSet inst_tvs - bind_me tv | tv `elemVarSet` no_bind_set = Skolem - | otherwise = BindMe + bind_me tv _ty | tv `elemVarSet` no_bind_set = Apart + | otherwise = BindMe {- Note [Check type-family instance binders] |