Adding terminal function to Product.

roconnor · Apr 7, 2012 · 6b825b5 · 6b825b5
1 parent a970a81
commit 6b825b5
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/src/Control/Category/Product.hs b/src/Control/Category/Product.hs
@@ -21,6 +21,8 @@ class Tensor c => Product c where
   -- requires (f &&& g) . h === (f . h) &&& (g . h)
   -- and (fst &&& snd) === id
   (&&&) :: c x y -> c x z -> c x (y, z)
+  terminal :: c x ()
 
 instance Product (->) where
   (&&&) f g x = (f x, g x)
+  terminal _ = ()