From 5390756aa46b1ae2cf1e274af8f2fdc24ed8009c Mon Sep 17 00:00:00 2001
From: eug-vs <eugene@eug-vs.xyz>
Date: Mon, 4 Sep 2023 04:57:02 +0300
Subject: fix: never panic in search, return option instead

Will Result type be better?
---
 src/grossmeister/search.rs | 32 ++++++++++++++++----------------
 1 file changed, 16 insertions(+), 16 deletions(-)

(limited to 'src/grossmeister/search.rs')

diff --git a/src/grossmeister/search.rs b/src/grossmeister/search.rs
index cad2b99..d3dc0b4 100644
--- a/src/grossmeister/search.rs
+++ b/src/grossmeister/search.rs
@@ -233,7 +233,7 @@ impl Grossmeister {
         alpha
     }
 
-    pub fn iterative_deepening(&mut self, max_depth: u8) -> (f32, Vec<Move>) {
+    pub fn iterative_deepening(&mut self, max_depth: u8) -> Option<(f32, Vec<Move>)> {
         let mut result = None;
         let mut depth = 1;
         let mut alpha = -INFINITY;
@@ -310,17 +310,17 @@ impl Grossmeister {
 
         println!("info hashfull {}", 1000 * self.transposition_table.iter().filter(|item| item.is_some()).count() / self.transposition_table.len());
 
-        match result {
-            Some(r) => {
+        if let Some(r) = result.clone() {
+            if !r.1.is_empty() {
                 print!("bestmove {}", r.1[0]);
-                if r.1.len() > 1 {
-                    print!(" ponder {}", r.1[1])
-                }
-                println!();
-                r
             }
-            None => panic!("No move found by search")
+            if r.1.len() > 1 {
+                print!(" ponder {}", r.1[1])
+            }
+            println!();
         }
+
+        result
     }
 
     pub fn perft(&mut self, depth: u8, print: bool) -> PerftResult {
@@ -436,7 +436,7 @@ mod tests {
         let fen = String::from("2kr1b1r/pp1npppp/2p1bn2/7q/5B2/2NB1Q1P/PPP1N1P1/2KR3R w - - 0 1");
         let board = Board::from_FEN(fen);
         let mut gm = Grossmeister::new(board);
-        let (score, pv) = gm.iterative_deepening(8);
+        let (score, pv) = gm.iterative_deepening(8).unwrap();
 
         assert_eq!(score, SCORE_MATE - 3.0);
         assert_eq!(pv, vec![
@@ -452,7 +452,7 @@ mod tests {
         let board = Board::from_FEN(fen);
 
         let mut gm = Grossmeister::new(board);
-        let (_, pv) = gm.iterative_deepening(6);
+        let (_, pv) = gm.iterative_deepening(6).unwrap();
         assert_eq!(
             pv[0],
             Move { source: Square::F5, target: Square::H4, kind: MoveKind::Quiet },
@@ -466,7 +466,7 @@ mod tests {
         let board = Board::from_FEN(fen);
 
         let mut gm = Grossmeister::new(board);
-        let (_, pv) = gm.iterative_deepening(5);
+        let (_, pv) = gm.iterative_deepening(5).unwrap();
         assert_eq!(
             pv[0],
             Move { source: Square::C2, target: Square::C3, kind: MoveKind::Quiet },
@@ -481,7 +481,7 @@ mod tests {
 
         let mut gm = Grossmeister::new(board);
         gm.debug = true;
-        let (score, pv) = gm.iterative_deepening(5);
+        let (score, pv) = gm.iterative_deepening(5).unwrap();
         dbg!(score, pv);
         assert_eq!(SCORE_MATE - score, 3.0); // Mate in 3 plies
     }
@@ -493,7 +493,7 @@ mod tests {
 
         let mut gm = Grossmeister::new(board);
         gm.debug = true;
-        let (score, pv) = gm.iterative_deepening(5);
+        let (score, pv) = gm.iterative_deepening(5).unwrap();
         dbg!(score, pv);
         assert_eq!(score + SCORE_MATE, 4.0); // Mate in 4 plies
     }
@@ -505,7 +505,7 @@ mod tests {
 
         let mut gm = Grossmeister::new(board);
         gm.debug = true;
-        let (score, pv) = gm.iterative_deepening(5);
+        let (score, pv) = gm.iterative_deepening(5).unwrap();
         dbg!(score, pv);
         assert_eq!(SCORE_MATE - score, 3.0); // Mate in 3 plies
     }
@@ -517,7 +517,7 @@ mod tests {
 
         let mut gm = Grossmeister::new(board);
         gm.debug = true;
-        let (score, pv) = gm.iterative_deepening(5);
+        let (score, pv) = gm.iterative_deepening(5).unwrap();
         dbg!(score, pv);
         assert!(score <= 0.0);
     }
-- 
cgit v1.2.3