diff options
Diffstat (limited to 'compiler/GHC/Tc/Utils/Unify.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/Unify.hs | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/compiler/GHC/Tc/Utils/Unify.hs b/compiler/GHC/Tc/Utils/Unify.hs index 5a4fe715c6..0ad43fe32e 100644 --- a/compiler/GHC/Tc/Utils/Unify.hs +++ b/compiler/GHC/Tc/Utils/Unify.hs @@ -1566,7 +1566,7 @@ There are three reasons not to unify: between levels 'n' and 'l'. Exactly what is a "given equality" for the purpose of (UNTOUCHABLE)? - Answer: see Note [Tracking Given equalities] in GHC.Tc.Solver.Monad + Answer: see Note [Tracking Given equalities] in GHC.Tc.Solver.InertSet 3. (TYVAR-TV) Unifying TyVarTvs and CycleBreakerTvs This precondition looks at the MetaInfo of the unification variable: @@ -1608,7 +1608,7 @@ Needless to say, all three have wrinkles: * In the constraint solver, we track where Given equalities occur and use that to guard unification in GHC.Tc.Solver.Canonical.unifyTest - More details in Note [Tracking Given equalities] in GHC.Tc.Solver.Monad + More details in Note [Tracking Given equalities] in GHC.Tc.Solver.InertSet Historical note: in the olden days (pre 2021) the constraint solver also used to unify only if l=n. Equalities were "floated" out of the @@ -1704,7 +1704,7 @@ Wanteds and Givens, but either way, deepest wins! Simple. Otherwise it can't. By putting the deepest variable on the left we maximise our changes of eliminating skolem capture. - See also GHC.Tc.Solver.Monad Note [Let-bound skolems] for another reason + See also GHC.Tc.Solver.InertSet Note [Let-bound skolems] for another reason to orient with the deepest skolem on the left. IMPORTANT NOTE: this test does a level-number comparison on |