From 1b195b0f91c24638ccae5a72a3abe7afc3e1aace Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Fri, 28 Feb 2025 17:50:04 -0500
Subject: [PATCH] cleanup

---
 src/logic/future_moves.rs | 31 ++++++++++++++++---------------
 1 file changed, 16 insertions(+), 15 deletions(-)

diff --git a/src/logic/future_moves.rs b/src/logic/future_moves.rs
index b21f4dc..a8bf47c 100644
--- a/src/logic/future_moves.rs
+++ b/src/logic/future_moves.rs
@@ -59,6 +59,7 @@ impl FutureMoves {
         self.arena.len()
     }
 
+    /// Returns indexes of leaf [`Move`]s, sorted by their depth (increasing order)
     fn leaf_moves(&self) -> Vec<usize> {
         let mut indexes = (0..self.arena.len())
             // we want to select all nodes that don't have children, or are lazy (need to maybe be regenerated)
@@ -122,7 +123,6 @@ impl FutureMoves {
             self.prune_bad_children();
             self.current_depth += 1;
             if cf.is_break() {
-                // println!("extend_layers: early break");
                 return;
             }
         }
@@ -231,6 +231,7 @@ impl FutureMoves {
                     .map(|&child| self.arena[child].value.expect("child has no value??"))
                     // average value of children
                     .sum::<i128>()
+                    // divide in order to calculate average value of all children
                     .checked_div(self.arena[idx].children.len() as i128)
                     .unwrap_or(0);
 
@@ -350,17 +351,16 @@ impl FutureMoves {
                     ));
                 }
             }
+
+            if !self.is_connected_to_root(idx) {
+                errors.push(format!("{}: not connected to root in any way", idx));
+            }
         }
         errors
     }
 
     fn prune_bad_children(&mut self) {
-        if self
-            .config
-            .max_depth
-            .saturating_sub(self.config.min_arena_depth_sub)
-            > self.current_depth
-        {
+        if self.config.max_depth > self.current_depth + self.config.min_arena_depth_sub {
             return;
         }
 
@@ -425,23 +425,23 @@ impl FutureMoves {
 
         let mut index_map = vec![None; self.arena.len()];
 
-        let new_start: Vec<(usize, usize, Move)> = retain
+        let (indexes, moves): (Vec<(usize, usize)>, Vec<Move>) = retain
             .into_iter()
             .enumerate() // old_idx
             .zip(self.arena.drain(..))
             .filter(|&((_, keep), _)| keep) // filter out un-related nodes
             .map(|((old_idx, _), node)| (old_idx, node))
             .enumerate() // new_idx
-            .map(|(a, (b, c))| (a, b, c))
-            .collect();
+            .map(|(new_idx, (old_idx, node))| ((new_idx, old_idx), node))
+            .unzip();
 
-        for &(new_idx, old_idx, _) in &new_start {
+        for (new_idx, old_idx) in indexes {
             index_map[old_idx] = Some(new_idx);
         }
 
-        self.arena = new_start
+        self.arena = moves
             .into_iter()
-            .map(|(_, _, mut node)| {
+            .map(|mut node| {
                 if let Some(parent) = node.parent.as_mut() {
                     if let Some(new_parent) = index_map[*parent] {
                         *parent = new_parent;
@@ -452,8 +452,9 @@ impl FutureMoves {
                 }
 
                 for c in node.children.as_mut_slice() {
-                    debug_assert!(
-                        index_map.get(*c).unwrap().is_some(),
+                    debug_assert_ne!(
+                        index_map.get(*c).and_then(|&x| x),
+                        None,
                         "index_map should contain the child's index"
                     );
                     *c = unsafe { index_map.get_unchecked(*c).unwrap_unchecked() };