Make mvv_lva to map pieces to their material score instead of abritrary matrix

Add time limits, use anyhow crate to improve error handling, remove depth limit on quiescence search

src/search/quiescence.rs

@@ -1,17 +1,19 @@
-use crate::{board::game::Game, evaluation::evaluation::evaluate_position, movegen::r#move::Move};
+use anyhow::{bail, Result};
 
-use super::move_ordering::score_by_mvv_lva;
+use crate::{board::game::Game, evaluation::evaluation::evaluate_position};
 
-pub fn quiescence(game: &mut Game, mut alpha: i32, beta: i32, depth: u8) -> (Option<Move>, i32) {
-    if depth == 0 {
-        return (None, evaluate_position(&game.board));
+use super::{iterative_deepening::hard_limit, move_ordering::mvv_lva, time::TimeInfo};
+
+pub fn quiescence(game: &mut Game, mut alpha: i32, beta: i32, time_info: &TimeInfo) -> Result<i32> {
+    if hard_limit(&time_info.time, time_info.remaining_time_in_ms) {
+        bail!("Time is up! In Quiescence");
     }
 
     let color = game.current_player();
     let stand_pat = evaluate_position(&game.board);
 
     if stand_pat >= beta {
-        return (None, beta);
+        return Ok(beta);
     }
 
     if alpha < stand_pat {
@@ -19,7 +21,7 @@ pub fn quiescence(game: &mut Game, mut alpha: i32, beta: i32, depth: u8) -> (Opt
     }
 
     let mut captures: Vec<_> = game.board.pseudo_moves_all_captures();
-    captures.sort_unstable_by_key(|mv| score_by_mvv_lva(&game.mailbox, *mv));
+    captures.sort_unstable_by_key(|mv| mvv_lva(&game.mailbox, *mv));
 
     for mv in captures {
         game.make_move(&mv);
@@ -28,16 +30,17 @@ pub fn quiescence(game: &mut Game, mut alpha: i32, beta: i32, depth: u8) -> (Opt
             game.unmake_move();
             continue;
         }
-
-        let move_score = -quiescence(game, -beta, -alpha, depth - 1).1;
+        let move_score = -quiescence(game, -beta, -alpha, time_info)?;
         game.unmake_move();
 
         if move_score >= beta {
-            return (Some(mv), beta);
+            return Ok(beta);
         }
 
-        alpha = alpha.max(move_score);
+        if alpha > move_score {
+            alpha = move_score
+        }
     }
 
-    (None, alpha)
+    Ok(alpha)
 }