Make the test non-trivial again

1 files changed, 12 insertions, 4 deletions

diff --git a/test/Main.hs b/test/Main.hs
index 209b88e..37e75b3 100644
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -8,8 +8,9 @@
 module Main where
 
 import Data.Dependent.EnumMap.Strict qualified as DE
+import Data.Dependent.EnumMap.Strict.Internal (coe1)
 import Data.Dependent.Sum
-
+import Data.Functor.Const
 
 data Tag = A | B | C
   deriving (Show)
@@ -21,9 +22,16 @@ data STag tag where
 deriving instance Show (STag tag)
 
 instance DE.Enum1 STag where
-  type Enum1Info STag = STag
-  fromEnum1 = \case { SA -> (0, SA); SB -> (1, SB); SC -> (2, SC) }
-  toEnum1 n t = case (n, t) of { (0, SA) -> SA; (1, SB) -> SB; (2, SC) -> SC; _ -> error "invalid tag" }
+  type Enum1Info STag = Const ()
+  fromEnum1 = \case
+                SA -> (0, Const ())
+                SB -> (1, Const ())
+                SC -> (2, Const ())
+  toEnum1 n _ = case n of
+                  0 -> coe1 SA
+                  1 -> coe1 SB
+                  2 -> coe1 SC
+                  _ -> error "invalid tag"
 
 data Value tag where
   VA :: Int -> Value A