diff --git a/src/board.rs b/src/board.rs
index 00fc5b3..d156ac6 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -109,6 +109,8 @@ impl Board {
                 .map(|range| range.into_iter().map(|j| (i, j)).collect()),
         );
 
+        // TODO! add diagonals to `chains` here
+
         let mut captured: usize = 0;
 
         for chain in chains {