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Diffstat (limited to 'compiler/GHC/Tc/Solver/Rewrite.hs')
-rw-r--r-- | compiler/GHC/Tc/Solver/Rewrite.hs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/GHC/Tc/Solver/Rewrite.hs b/compiler/GHC/Tc/Solver/Rewrite.hs index 7e4993ad8d..42a00d73ba 100644 --- a/compiler/GHC/Tc/Solver/Rewrite.hs +++ b/compiler/GHC/Tc/Solver/Rewrite.hs @@ -897,6 +897,11 @@ data RewriteTvResult -- ^ The tyvar rewrites to a not-necessarily rewritten other type. -- co :: new type ~r old type, where the role is determined by -- the RewriteEnv + -- + -- With Quick Look, the returned TcType can be a polytype; + -- that is, in the constraint solver, a unification variable + -- can contain a polytype. See GHC.Tc.Gen.App + -- Note [Instantiation variables are short lived] rewriteTyVar :: TyVar -> RewriteM (Xi, Coercion) rewriteTyVar tv |