Add initial material-based board eval

probably other stuff

Cargo.lock

@@ -196,6 +196,12 @@ dependencies = [
  "crypto-common",
 ]
 
+[[package]]
+name = "either"
+version = "1.8.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90e5c1c8368803113bf0c9584fc495a58b86dc8a29edbf8fe877d21d9507e797"
+
 [[package]]
 name = "failure"
 version = "0.1.8"
@@ -274,10 +280,20 @@ name = "inkwell"
 version = "0.1.0"
 dependencies = [
  "chess",
+ "itertools",
  "rand 0.8.5",
  "vampirc-uci",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "js-sys"
 version = "0.3.60"

Cargo.toml

@@ -7,5 +7,6 @@ edition = "2021"
 
 [dependencies]
 chess = "3.2.0"
+itertools = "0.10.5"
 rand = "0.8.5"
 vampirc-uci = { version = "0.11.1", features = ["chess"] }

src/config.rs

@@ -18,3 +18,6 @@ pub const INFO: Info = Info {
     version: "0.0.1-rc",
     author: "Bendy (real)",
 };
+
+// FIXME: this needs to be configurable via UCI
+pub const depth: u8 = 0;

src/eval.rs

@@ -0,0 +1,20 @@
+use chess::{Board, ChessMove, Color, MoveGen, Piece};
+
+pub fn eval_board(board: Board, playing_as: Color, curr_depth: u8) -> i128 {
+    let mut current_eval: i128 = 0;
+
+    let moves_iter = MoveGen::new_legal(&board).into_iter();
+
+    moves_iter.for_each(|mov| {
+        let tmp_board = board.make_move_new(mov);
+        current_eval += tmp_board.color_combined(playing_as).count() as i128;
+        current_eval -= tmp_board.color_combined(!playing_as).count() as i128;
+        eprintln!("{}", current_eval);
+        if curr_depth != 0 {
+            eprintln!("{}", curr_depth);
+            current_eval += eval_board(tmp_board, playing_as, curr_depth - 1)
+        }
+    });
+
+    return current_eval;
+}

src/main.rs

@@ -1,7 +1,10 @@
 mod config;
+mod eval;
 
-use chess::{Board, MoveGen, EMPTY};
+use chess::{Board, MoveGen};
 use config::INFO;
+use eval::eval_board;
+use itertools::Itertools;
 use rand::seq::IteratorRandom;
 use std::io::{self, BufRead};
 use std::process;
@@ -11,6 +14,8 @@ use vampirc_uci::{
     MessageList, Serializable, UciMessage, UciOptionConfig, UciSearchControl, UciTimeControl,
 };
 
+use crate::config::depth;
+
 fn main() {
     let mut rng = rand::thread_rng();
     let mut board: Option<Board> = None;
@@ -41,10 +46,7 @@ fn main() {
                 moves,
             } => {
                 if startpos {
-                    board = Some(
-                        Board::from_str("rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
-                            .unwrap(),
-                    )
+                    board = Some(Board::default())
                 }
                 if let Some(fen) = fen {
                     board = Some(Board::from_str(fen.as_str()).expect("Invalid FEN board"))
@@ -88,16 +90,30 @@ fn main() {
                 }
 
                 if let Some(board) = board {
-                    let iter = MoveGen::new_legal(&board).into_iter();
+                    let color = board.side_to_move();
+                    let moves = MoveGen::new_legal(&board).into_iter();
+                    let iter = moves.map(|mov| (mov, board.make_move_new(mov)));
 
-                    println!("bestmove {}", iter.choose(&mut rng).unwrap());
+                    println!(
+                        "bestmove {}",
+                        iter.sorted_by(|a, b| Ord::cmp(
+                            &eval_board(b.1, color, depth),
+                            &eval_board(a.1, color, depth)
+                        ))
+                        .next()
+                        .unwrap()
+                        .0
+                    );
                 }
             }
+            UciMessage::Stop => {
+                // FIXME: impl
+            }
             UciMessage::Quit => {
                 process::exit(0);
             }
             _ => {
-                todo!()
+                todo!("{}", msg.to_string())
             }
         }
     }