diff options
Diffstat (limited to 'testsuite/tests/indexed-types/should_compile/HO.hs')
| -rw-r--r-- | testsuite/tests/indexed-types/should_compile/HO.hs | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/testsuite/tests/indexed-types/should_compile/HO.hs b/testsuite/tests/indexed-types/should_compile/HO.hs new file mode 100644 index 0000000000..40d597a76f --- /dev/null +++ b/testsuite/tests/indexed-types/should_compile/HO.hs @@ -0,0 +1,18 @@ +{-# LANGUAGE TypeFamilies, TypeOperators, RankNTypes #-} + +module HO where + +import Data.IORef + +type family SMRef (m::(* -> *)) :: * -> * +type family SMMonad (r::(* -> *)) :: * -> * + +type instance SMRef IO = IORef +type instance SMMonad IORef = IO + + +class SMMonad (SMRef m) ~ m => SM m where + new :: forall a. a -> m (SMRef m a) + read :: forall a. (SMRef m a) -> m a + write :: forall a. (SMRef m a) -> a -> m () + |