diff options
Diffstat (limited to 'compiler/GHC/Tc/Utils/Unify.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/Unify.hs | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/compiler/GHC/Tc/Utils/Unify.hs b/compiler/GHC/Tc/Utils/Unify.hs index 41faa2fece..eea0ed95ef 100644 --- a/compiler/GHC/Tc/Utils/Unify.hs +++ b/compiler/GHC/Tc/Utils/Unify.hs @@ -1477,8 +1477,8 @@ tcSkolemiseScoped ctxt expected_ty thing_inside = do { deep_subsumption <- xoptM LangExt.DeepSubsumption ; let skolemise | deep_subsumption = deeplySkolemise | otherwise = topSkolemise - ; -- This (unpleasant) rec block allows us to pass skol_info to deeplySkolemise; - -- but skol_info can't be built until we have tv_prs + ; -- rec {..}: see Note [Keeping SkolemInfo inside a SkolemTv] + -- in GHC.Tc.Utils.TcType rec { (wrap, tv_prs, given, rho_ty) <- skolemise skol_info expected_ty ; skol_info <- mkSkolemInfo (SigSkol ctxt expected_ty tv_prs) } @@ -1495,7 +1495,9 @@ tcTopSkolemise ctxt expected_ty thing_inside = do { res <- thing_inside expected_ty ; return (idHsWrapper, res) } | otherwise - = do { rec { (wrap, tv_prs, given, rho_ty) <- topSkolemise skol_info expected_ty + = do { -- rec {..}: see Note [Keeping SkolemInfo inside a SkolemTv] + -- in GHC.Tc.Utils.TcType + rec { (wrap, tv_prs, given, rho_ty) <- topSkolemise skol_info expected_ty ; skol_info <- mkSkolemInfo (SigSkol ctxt expected_ty tv_prs) } ; let skol_tvs = map snd tv_prs |