From 4eb734d3eb9df150f2aa456f254fd413552ae3f2 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Thu, 21 Dec 2023 08:17:06 -0800
Subject: [PATCH] [board] Some basic bit operations for bitboards

---
 board/src/bitboard.rs | 46 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/board/src/bitboard.rs b/board/src/bitboard.rs
index 68429fb..4579e47 100644
--- a/board/src/bitboard.rs
+++ b/board/src/bitboard.rs
@@ -1,4 +1,50 @@
 // Eryn Wells <eryn@erynwells.me>
 
+use crate::square::Square;
+
 #[derive(Clone, Copy, Debug, Default, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct BitBoard(pub u64);
+
+impl BitBoard {
+    fn is_empty(&self) -> bool {
+        self.0 == 0
+    }
+
+    fn has_piece_at(&self, sq: &Square) -> bool {
+        (self.0 & (1 << sq.index)) > 0
+    }
+
+    fn place_piece_at(&mut self, sq: &Square) {
+        self.0 |= 1 << sq.index
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::square::Square;
+
+    #[test]
+    fn is_empty() {
+        assert!(BitBoard(0).is_empty());
+    }
+
+    #[test]
+    fn has_piece_at() {
+        let bb = BitBoard(0b1001100);
+
+        assert!(bb.has_piece_at(
+            &Square::from_algebraic_string("a3").expect("Unable to get square for 'a3'")
+        ));
+        assert!(!bb.has_piece_at(
+            &Square::from_algebraic_string("a2").expect("Unable to get square for 'a2'")
+        ));
+    }
+
+    #[test]
+    fn place_piece_at() {
+        let mut bb = BitBoard(0b1001100);
+        bb.place_piece_at(&Square::from_index(34).expect("Invalid square index"));
+        assert!(bb.has_piece_at(&Square::from_index(34).expect("Invalid square index")));
+    }
+}