lude

commit e9e58113e990affacef44e78376bcd6977fbc7a7
parent 0bc08b1b68e4048ad9b4bef33ece8f62c5472087
Author: Robert Russell <robert@rr3.xyz>
Date:   Tue, 10 Mar 2026 18:11:48 -0700

Add Fst and Snd

Diffstat:
M
src/Lude/Kind.hs
 | 
10
++++++++++

1 file changed, 10 insertions(+), 0 deletions(-)
diff --git a/src/Lude/Kind.hs b/src/Lude/Kind.hs
@@ -1,5 +1,7 @@
 module Lude.Kind (
     Kind,
+    Fst,
+    Snd,
     Type,
     TypeL,
     TypeU,
@@ -20,6 +22,14 @@ type Kind = GHC.TYPE Repr.BoxL
 
 --------------------------------------------------------------------------------
 
+type family Fst (p :: (i, j)) :: i where
+    Fst '(a, b) = a
+
+type family Snd (p :: (i, j)) :: j where
+    Snd '(a, b) = b
+
+--------------------------------------------------------------------------------
+
 type Type :: forall (r :: Repr). Kind
 type Type @r = GHC.TYPE r