add board weights

src/logic/board_value.rs

@@ -18,19 +18,28 @@ impl BoardValueMap {
             .sum()
     }
 
+    /// Weights from: https://repub.eur.nl/pub/7142/ei2005-47.pdf
     pub fn new() -> Self {
         let mut map = PosMap::new();
+        assert_eq!(
+            Board::BOARD_SIZE,
+            8,
+            "BVM only supports Board::BOARD_SIZE of 8"
+        );
+
+        const POSITION_VALUES: [[i64; 8]; 8] = [
+            [100, -20, 10, 5, 5, 10, -20, 100],
+            [-20, -50, -2, -2, -2, -2, -50, -20],
+            [10, -2, -1, -1, -1, -1, -2, 10],
+            [5, -2, -1, -1, -1, -1, -2, 5],
+            [5, -2, -1, -1, -1, -1, -2, 5],
+            [10, -2, -1, -1, -1, -1, -2, 10],
+            [-20, -50, -2, -2, -2, -2, -50, -20],
+            [100, -20, 10, 5, 5, 10, -20, 100],
+        ];
 
         for (i, j) in Board::all_positions() {
-            map.set(i, j, 1);
-        }
-
-        for (i, j) in Board::sides() {
-            map.set(i, j, 100);
-        }
-
-        for (i, j) in Board::corners() {
-            map.set(i, j, 1000);
+            map.set(i, j, POSITION_VALUES[i][j])
         }
 
         Self(map)