diff options
Diffstat (limited to 'compiler/GHC/Tc/Validity.hs')
| -rw-r--r-- | compiler/GHC/Tc/Validity.hs | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/compiler/GHC/Tc/Validity.hs b/compiler/GHC/Tc/Validity.hs index 68ef82785d..87be216d9b 100644 --- a/compiler/GHC/Tc/Validity.hs +++ b/compiler/GHC/Tc/Validity.hs @@ -254,11 +254,11 @@ checkUserTypeError :: Type -> TcM () checkUserTypeError = check where check ty - | Just msg <- userTypeError_maybe ty = fail_with msg - | Just (_,ts) <- splitTyConApp_maybe ty = mapM_ check ts - | Just (t1,t2) <- splitAppTy_maybe ty = check t1 >> check t2 - | Just (_,t1) <- splitForAllTy_maybe ty = check t1 - | otherwise = return () + | Just msg <- userTypeError_maybe ty = fail_with msg + | Just (_,ts) <- splitTyConApp_maybe ty = mapM_ check ts + | Just (t1,t2) <- splitAppTy_maybe ty = check t1 >> check t2 + | Just (_,t1) <- splitForAllTyCoVar_maybe ty = check t1 + | otherwise = return () fail_with msg = do { env0 <- tcInitTidyEnv ; let (env1, tidy_msg) = tidyOpenType env0 msg @@ -751,7 +751,7 @@ check_type ve@(ValidityEnv{ ve_tidy_env = env, ve_ctxt = ctxt ; checkEscapingKind env' tvbs' theta tau } where - (tvbs, phi) = tcSplitForAllVarBndrs ty + (tvbs, phi) = tcSplitForAllTyVarBinders ty (theta, tau) = tcSplitPhiTy phi (env', tvbs') = tidyTyCoVarBinders env tvbs @@ -1056,7 +1056,7 @@ case, but this can lead to bugs. Imagine you have this scenario (from #15954): If the rank-n case came first, then in the process of checking for `forall`s or contexts, we would expand away `B A` to `forall x. x -> x`. This is because the functions that split apart `forall`s/contexts -(tcSplitForAllVarBndrs/tcSplitPhiTy) expand type synonyms! If `B A` is expanded +(tcSplitForAllTyVarBinders/tcSplitPhiTy) expand type synonyms! If `B A` is expanded away to `forall x. x -> x` before the actually validity checks occur, we will have completely obfuscated the fact that we had an unsaturated application of the `A` type synonym. |