diff options
Diffstat (limited to 'compiler/GHC/Core/Coercion.hs')
| -rw-r--r-- | compiler/GHC/Core/Coercion.hs | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/compiler/GHC/Core/Coercion.hs b/compiler/GHC/Core/Coercion.hs index 4cfdc3ee82..235e8c65fb 100644 --- a/compiler/GHC/Core/Coercion.hs +++ b/compiler/GHC/Core/Coercion.hs @@ -792,14 +792,15 @@ mkTyConAppCo r tc cos | otherwise = TyConAppCo r tc cos -- | Build a function 'Coercion' from two other 'Coercion's. That is, --- given @co1 :: a ~ b@ and @co2 :: x ~ y@ produce @co :: (a -> x) ~ (b -> y)@. +-- given @co1 :: a ~ b@ and @co2 :: x ~ y@ produce @co :: (a -> x) ~ (b -> y)@ +-- or @(a => x) ~ (b => y)@, depending on the kind of @a@/@b@. mkFunCo :: Role -> CoercionN -> Coercion -> Coercion -> Coercion mkFunCo r w co1 co2 -- See Note [Refl invariant] | Just (ty1, _) <- isReflCo_maybe co1 , Just (ty2, _) <- isReflCo_maybe co2 , Just (w, _) <- isReflCo_maybe w - = mkReflCo r (mkVisFunTy w ty1 ty2) + = mkReflCo r (mkFunctionType w ty1 ty2) | otherwise = FunCo r w co1 co2 -- | Apply a 'Coercion' to another 'Coercion'. |