From 626ac6245e79e72554a2538c8f4b36266ff8a462 Mon Sep 17 00:00:00 2001
From: Eryn Wells <eryn@erynwells.me>
Date: Sat, 6 Jan 2024 20:34:16 -0800
Subject: [PATCH] [board] Copy the update_moves_with_ray macro into the rook
 move generator

This is an ugly copy/paste operation, but reduces the code in rook::ClassicalMoveGenerator somewhat.
---
 board/src/moves/rook.rs | 55 +++++++++++++----------------------------
 1 file changed, 17 insertions(+), 38 deletions(-)

diff --git a/board/src/moves/rook.rs b/board/src/moves/rook.rs
index d5526da..82b8c76 100644
--- a/board/src/moves/rook.rs
+++ b/board/src/moves/rook.rs
@@ -1,7 +1,5 @@
 // Eryn Wells <eryn@erynwells.me>
 
-use std::io::empty;
-
 use super::{move_generator_declaration, MoveGeneratorInternal, MoveSet};
 use crate::{
     bitboard::BitBoard,
@@ -29,44 +27,25 @@ impl<'pos> MoveGeneratorInternal for ClassicalMoveGenerator<'pos> {
 
         let mut all_moves = BitBoard::empty();
 
-        // Find the first occupied square along the northward ray. Do this by
-        // looking at the squares along that ray in trailing (south to north)
-        // order.
-        let ray = BitBoard::ray(square, Direction::North);
-        if let Some(first_occupied_square) = (ray & blockers).occupied_squares_trailing().next() {
-            let remainder = BitBoard::ray(first_occupied_square, Direction::North);
-            let attack_ray = ray & !remainder;
-            all_moves |= attack_ray;
-        } else {
-            all_moves |= ray;
+        macro_rules! update_moves_with_ray {
+            ($direction:ident, $occupied_squares:tt) => {
+                let ray = BitBoard::ray(square, Direction::$direction);
+                if let Some(first_occupied_square) =
+                    BitBoard::$occupied_squares(&(ray & blockers)).next()
+                {
+                    let remainder = BitBoard::ray(first_occupied_square, Direction::$direction);
+                    let attack_ray = ray & !remainder;
+                    all_moves |= attack_ray;
+                } else {
+                    all_moves |= ray;
+                }
+            };
         }
 
-        let ray = BitBoard::ray(square, Direction::East);
-        if let Some(first_occupied_square) = (ray & blockers).occupied_squares_trailing().next() {
-            let remainder = BitBoard::ray(first_occupied_square, Direction::East);
-            let attack_ray = ray & !remainder;
-            all_moves |= attack_ray;
-        } else {
-            all_moves |= ray;
-        }
-
-        let ray = BitBoard::ray(square, Direction::South);
-        if let Some(first_occupied_square) = (ray & blockers).occupied_squares().next() {
-            let remainder = BitBoard::ray(first_occupied_square, Direction::South);
-            let attack_ray = ray & !remainder;
-            all_moves |= attack_ray;
-        } else {
-            all_moves |= ray;
-        }
-
-        let ray = BitBoard::ray(square, Direction::West);
-        if let Some(first_occupied_square) = (ray & blockers).occupied_squares().next() {
-            let remainder = BitBoard::ray(first_occupied_square, Direction::West);
-            let attack_ray = ray & !remainder;
-            all_moves |= attack_ray;
-        } else {
-            all_moves |= ray;
-        }
+        update_moves_with_ray!(North, occupied_squares_trailing);
+        update_moves_with_ray!(East, occupied_squares_trailing);
+        update_moves_with_ray!(South, occupied_squares);
+        update_moves_with_ray!(West, occupied_squares);
 
         let quiet_moves_bb = all_moves & (empty_squares | !friendly_pieces);
         let capture_moves_bb = all_moves & opposing_pieces;