bitboard: remove unused multi shift

src/repr/bitboard.rs

@@ -46,38 +46,38 @@ impl BitBoard {
         self.0 == 0b0
     }
 
-    pub const fn east(&self, n: usize) -> Self {
+    pub const fn east(&self) -> Self {
         let mask = !Self::col_mask(Board::SIZE - 1).0; // Mask to block column BOARD_SIZE-1 bits
-        Self((self.0 & mask) << n)
+        Self((self.0 & mask) << 1)
     }
 
-    pub const fn west(&self, n: usize) -> Self {
+    pub const fn west(&self) -> Self {
         let mask = !Self::col_mask(0).0;
-        Self((self.0 & mask) >> n)
+        Self((self.0 & mask) >> 1)
     }
 
-    pub const fn north(&self, n: usize) -> Self {
-        Self(self.0 >> (Board::SIZE as usize * n))
+    pub const fn north(&self) -> Self {
+        Self(self.0 >> Board::SIZE)
     }
 
-    pub const fn south(&self, n: usize) -> Self {
-        Self(self.0 << (Board::SIZE as usize * n))
+    pub const fn south(&self) -> Self {
+        Self(self.0 << Board::SIZE)
     }
 
-    pub const fn northeast(&self, n: usize) -> Self {
-        self.north(n).east(n)
+    pub const fn northeast(&self) -> Self {
+        self.north().east()
     }
 
-    pub const fn northwest(&self, n: usize) -> Self {
-        self.north(n).west(n)
+    pub const fn northwest(&self) -> Self {
+        self.north().west()
     }
 
-    pub const fn southeast(&self, n: usize) -> Self {
-        self.south(n).east(n)
+    pub const fn southeast(&self) -> Self {
+        self.south().east()
     }
 
-    pub const fn southwest(&self, n: usize) -> Self {
-        self.south(n).west(n)
+    pub const fn southwest(&self) -> Self {
+        self.south().west()
     }
 
     // Mask for a specific column (e.g., col_mask(7) = 0x8080808080808080)
@@ -133,15 +133,4 @@ mod test {
         b.set((2, 4).into(), false);
         assert!(!b.get((2, 4).into()));
     }
-
-    #[test]
-    fn dir_multi() {
-        let mut base = BitBoard::from_coord(CoordPair::from_axes(4, 4));
-        base = base.southeast(1);
-        base = base.southeast(1);
-        assert_eq!(
-            base,
-            BitBoard::from_coord(CoordPair::from_axes(4, 4)).southeast(2)
-        );
-    }
 }

src/repr/board.rs

@@ -294,7 +294,7 @@ impl Board {
                 // PERF! tested unrolling this loop using `const_for`
                 // resulted in a 9% slowdown
                 loop {
-                    current = $dir(&current, 1);
+                    current = $dir(&current);
                     if current.is_empty() || !current.intersects(*opponent_board) {
                         break;
                     }