From 5a08a4477e60d5720fb6a7e381df4ee66024b0a1 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Thu, 28 Dec 2023 12:10:39 -0700
Subject: [PATCH] [board] Implement BitBoard::shift_south

---
 board/src/bitboard/bitboard.rs | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/board/src/bitboard/bitboard.rs b/board/src/bitboard/bitboard.rs
index f5f0e6c..f777d64 100644
--- a/board/src/bitboard/bitboard.rs
+++ b/board/src/bitboard/bitboard.rs
@@ -67,6 +67,11 @@ impl BitBoard {
         BitBoard(self.0 >> 7 & BitBoard::NOT_A_FILE)
     }
 
+    #[inline]
+    pub fn shift_south(&self, n: u8) -> BitBoard {
+        BitBoard(self.0 >> (8 * n))
+    }
+
     #[inline]
     pub fn shift_south_one(&self) -> BitBoard {
         BitBoard(self.0 >> 8)
@@ -237,6 +242,11 @@ mod tests {
             BitBoard(0x0008_0000_0000).shift_north(2),
             BitBoard(0x0008_0000_0000_0000)
         );
+
+        assert_eq!(
+            BitBoard(0x0008_0000_0000).shift_south(2),
+            BitBoard(0x0008_0000)
+        );
     }
 
     #[test]