make complexagent so much better

src/board.rs

@@ -6,7 +6,7 @@ use std::{cmp::Ordering, fmt};
 
 pub const BOARD_SIZE: usize = 8;
 
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, PartialEq, Eq)]
 pub struct Board {
     board: [[Option<Piece>; BOARD_SIZE]; BOARD_SIZE],
 }
@@ -78,7 +78,7 @@ impl Board {
         Box::new(
             (0..BOARD_SIZE)
                 .flat_map(|i| (0..BOARD_SIZE).map(move |j| (i, j)))
-                .filter(move |(i, j)| self.what_if(*i, *j, color).is_some()),
+                .filter(move |(i, j)| self.would_prop(*i, *j, color)),
         )
     }
 
@@ -111,6 +111,10 @@ impl Board {
         Some((self_copy, how_many_prop))
     }
 
+    pub fn would_prop(&self, i: usize, j: usize, piece: Piece) -> bool {
+        !self.propegate_from_dry(i, j, piece).is_empty()
+    }
+
     pub fn place(&mut self, i: usize, j: usize, piece: Piece) -> Result<(), String> {
         if let Some(what_if_result) = self.what_if(i, j, piece) {
             if what_if_result.1 > 0 {
@@ -121,15 +125,24 @@ impl Board {
         Err("move would not propegate".to_string())
     }
 
-    /// Propegate piece captures originating from (i, j)
-    /// DO NOT USE THIS ALONE, this should be called as a part of
-    /// [`Board::place`] or [`Board::place_and_prop_unchecked`]
     fn propegate_from(&mut self, i: usize, j: usize) -> usize {
-        // returns if that place is empty
         let Some(starting_color) = *self.get(i, j) else {
             return 0;
         };
 
+        let pos_s = self.propegate_from_dry(i, j, starting_color);
+        let pos_len = pos_s.len();
+        for (i, j) in pos_s {
+            self.place_unchecked(i, j, starting_color);
+        }
+
+        pos_len
+    }
+
+    /// Propegate piece captures originating from (i, j)
+    /// DO NOT USE THIS ALONE, this should be called as a part of
+    /// [`Board::place`] or [`Board::place_and_prop_unchecked`]
+    fn propegate_from_dry(&self, i: usize, j: usize, starting_color: Piece) -> Vec<(usize, usize)> {
         // Create all chains from the piece being propegated from in `i` and `j` coordinates
         let (i_chain, j_chain) = (
             split_from(0, BOARD_SIZE - 1, i),
@@ -152,7 +165,7 @@ impl Board {
         // handle diagonals
         chains.extend(diag(i, j, 0, 0, BOARD_SIZE - 1, BOARD_SIZE - 1));
 
-        let mut captured: usize = 0;
+        let mut fill: Vec<(usize, usize)> = Vec::new();
 
         for chain in chains {
             for (chain_length, &(new_i, new_j)) in chain.iter().enumerate() {
@@ -166,11 +179,10 @@ impl Board {
                     let Some(history) = chain.get(..chain_length) else {
                         break;
                     };
-                    captured += history.len();
 
                     // fill all opposite colors with this color
                     for &(i_o, j_o) in history {
-                        self.place_unchecked(i_o, j_o, starting_color);
+                        fill.push((i_o, j_o));
                     }
                     // either the other pieces were replaced, or this was an invalid chain,
                     // in both cases, the loop needs to be breaked
@@ -178,7 +190,7 @@ impl Board {
                 }
             }
         }
-        captured
+        fill
     }
 
     /// Returns (White score, Black score)