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Diffstat (limited to 'compiler/GHC/Tc/Utils/TcType.hs')
| -rw-r--r-- | compiler/GHC/Tc/Utils/TcType.hs | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/compiler/GHC/Tc/Utils/TcType.hs b/compiler/GHC/Tc/Utils/TcType.hs index bf6967dccf..ef4f9741f6 100644 --- a/compiler/GHC/Tc/Utils/TcType.hs +++ b/compiler/GHC/Tc/Utils/TcType.hs @@ -1533,6 +1533,11 @@ tc_eq_type keep_syns vis_only orig_ty1 orig_ty2 = go orig_env orig_ty1 orig_ty2 where go :: RnEnv2 -> Type -> Type -> Bool + -- See Note [Comparing nullary type synonyms] in GHC.Core.Type. + go _ (TyConApp tc1 []) (TyConApp tc2 []) + | tc1 == tc2 + = True + go env t1 t2 | not keep_syns, Just t1' <- tcView t1 = go env t1' t2 go env t1 t2 | not keep_syns, Just t2' <- tcView t2 = go env t1 t2' |