Test Trac #5862

testsuite/tests/polykinds/T5862.hs

+{-# LANGUAGE PolyKinds,
+             TypeFamilies,
+             GADTs,
+             DataKinds,
+             KindSignatures
+ #-}
+
+module T5862 where
+
+data Nat = Zero | Succ Nat
+
+data SNat a where
+  SZero :: SNat 'Zero
+  SSucc :: SNat n -> SNat ('Succ n)
+
+data SBool a where
+  SFalse :: SBool 'False
+  STrue :: SBool 'True
+
+data SMaybe a where
+  SNothing :: SMaybe 'Nothing
+  SJust :: Sing a -> SMaybe ('Just a)
+
+type family Sing a
+type instance Sing (a :: Nat) = SNat a
+type instance Sing (a :: Bool) = SBool a
+type instance Sing (a :: Maybe *) = SMaybe a -- want to say Maybe k

testsuite/tests/polykinds/all.T

@@ -17,11 +17,13 @@ test('PolyKinds07', normal, compile_fail, [''])
 
 test('PolyKinds12', normal, compile, [''])
 
+test('Freeman', normal, compile_and_run, [''])
+test('MonoidsTF', normal, compile_and_run, [''])
+test('MonoidsFD', normal, compile_and_run, [''])
+
 test('T5798', normal, compile, [''])
 test('T5770', normal, compile, [''])
 test('T5771', normal, compile, [''])
 test('T5717', normal, compile, [''])
+test('T5862', normal, compile, [''])
 
-test('Freeman', normal, compile_and_run, [''])
-test('MonoidsTF', normal, compile_and_run, [''])
-test('MonoidsFD', normal, compile_and_run, [''])