arena fixes

src/logic/future_moves.rs

@@ -46,7 +46,7 @@ impl FutureMoves {
                 // we want to select all nodes that don't have children, or are lazy (need to maybe be regenerated)
                 .filter(|&idx| {
                     let got = &self.arena[idx];
-                    got.is_lazy || got.children.is_empty()
+                    got.is_trimmed || got.children.is_empty()
                 })
                 .filter(|&idx| self.is_connected_to_root(idx))
                 .collect::<Vec<usize>>()
@@ -317,23 +317,25 @@ impl FutureMoves {
         // values are needed in order to prune and see what's best
         self.compute_values(0..self.arena_len());
 
-        let by_depth =
-            self.by_depth((0..self.arena.len()).filter(|&i| self.is_connected_to_root(i)));
+        let by_depth = self.by_depth(0..self.arena.len());
 
         const TOP_K_CHIL: usize = 2;
 
-        // the lower the value, the more conservative
-        const UP_TO: usize = 5;
+        // the lower the value, the more conservative, what level to stop pruning at?
+        // a lower value allows more possible paths
+        let up_to = self.current_depth - 2;
 
-        // start pruning at X depth before self.max_depth
-        const START_PRUNING_AT_MINUS: usize = 2;
-        if self.max_depth > self.current_depth + START_PRUNING_AT_MINUS {
+        // start pruning at X depth before self.max_depth is reached
+        // used for pruning during tree generation before the tree is fully grown
+        const START_PRUNING_AT_MINUS: usize = 3;
+
+        if self.max_depth.saturating_sub(START_PRUNING_AT_MINUS) > self.current_depth {
             return;
         }
 
         for (depth, indexes) in by_depth {
             // TODO! maybe update by_depth every iteration or something?
-            if depth > UP_TO {
+            if depth > up_to {
                 return;
             }
 
@@ -344,10 +346,10 @@ impl FutureMoves {
 
             for idx in indexes {
                 let mut m = self.arena[idx].clone();
-                if m.is_lazy {
+                if m.is_trimmed {
                     continue;
                 }
-                m.is_lazy = true;
+                m.is_trimmed = true;
                 m.sort_children(&mut self.arena);
                 if m.children.len() > TOP_K_CHIL {
                     let drained = m.children.drain(TOP_K_CHIL..);
@@ -358,6 +360,8 @@ impl FutureMoves {
                 self.arena[idx] = m;
             }
         }
+
+        // rebuild tree to exclude the things that were pruned
         self.refocus_tree();
     }
 
@@ -444,7 +448,7 @@ mod tests {
             value: None,
             self_value: 0,
             color: Piece::Black,
-            is_lazy: false,
+            is_trimmed: false,
         });
 
         futm.update_root_idx_raw(0);
@@ -546,7 +550,7 @@ mod tests {
             value: None,
             self_value: 0,
             color: Piece::Black,
-            is_lazy: false,
+            is_trimmed: false,
         });
 
         futm.update_root_idx_raw(0);
@@ -610,7 +614,7 @@ mod tests {
             value: None,
             self_value: 0,
             color: Piece::Black,
-            is_lazy: false,
+            is_trimmed: false,
         });
 
         futm.update_root_idx_raw(0);

src/logic/move.rs

@@ -31,8 +31,8 @@ pub struct Move {
     /// Which color made a move on this move?
     pub color: Piece,
 
-    /// Was this child lazily created? (it will have delayed child generation)
-    pub is_lazy: bool,
+    /// Was this move's children previously trimmed?
+    pub is_trimmed: bool,
 }
 
 lazy_static! {
@@ -57,7 +57,7 @@ impl Move {
             children: Vec::new(),
             value: None,
             color,
-            is_lazy: false,
+            is_trimmed: false,
             self_value: 0,
         };
         m.self_value = m.compute_self_value(agent_color);