1 files changed, 28 insertions, 0 deletions
diff --git a/testsuite/tests/indexed-types/should_compile/T2219.hs b/testsuite/tests/indexed-types/should_compile/T2219.hs
new file mode 100644
index 0000000000..ea7d442f74
--- /dev/null
+++ b/testsuite/tests/indexed-types/should_compile/T2219.hs
@@ -0,0 +1,28 @@
+{-# LANGUAGE TypeFamilies, GADTs, EmptyDataDecls, TypeOperators #-}
+
+module Test where
+
+data Zero
+data Succ a
+
+data FZ
+data FS fn
+
+data Fin n fn where
+  FZ :: Fin (Succ n) FZ
+  FS :: Fin n fn -> Fin (Succ n) (FS fn)
+
+data Nil
+data a ::: b
+
+type family Lookup ts fn :: *
+type instance Lookup (t ::: ts) FZ = t
+type instance Lookup (t ::: ts) (FS fn) = Lookup ts fn
+
+data Tuple n ts where
+  Nil   :: Tuple Zero Nil
+  (:::) :: t -> Tuple n ts -> Tuple (Succ n) (t ::: ts)
+
+proj :: Fin n fn -> Tuple n ts -> Lookup ts fn
+proj FZ      (v ::: _)  = v
+proj (FS fn) (_ ::: vs) = proj fn vs