refactor how suggestion-updates are propagated to Bot and logged

fish/src/bot.rs

@@ -54,8 +54,16 @@ impl Bot {
         // same as "bot.think_for(2500); bot.think_for(5000 - bot.iterations());"
         let max_iters = self.iters + gas;
         while self.iters < max_iters {
-            self.algorithm
+            let did_update = self
+                .algorithm
                 .step(&self.arena, &self.evaluator, &mut self.iters);
+            if did_update {
+                tracing::debug!(
+                    "new suggestion @ {}: {:?}",
+                    self.iters,
+                    self.algorithm.best().unwrap(),
+                );
+            }
         }
     }
 
@@ -165,15 +173,20 @@ impl SegmentedAStar {
         self.best.map(|node| unsafe { node.as_node() })
     }
 
-    fn step(&mut self, arena: &Arena, eval: &Evaluator, iters: &mut u32) {
+    fn step(&mut self, arena: &Arena, eval: &Evaluator, iters: &mut u32) -> bool {
         *iters += 1;
         match self.expand(arena, eval) {
-            Ok(work) => *iters += work,
+            Ok(work) => {
+                *iters += work;
+                false
+            }
             Err(maybe_cand) => {
-                if let Some(cand) = maybe_cand {
-                    self.backup(cand, *iters);
-                }
                 self.select();
+                if let Some(cand) = maybe_cand {
+                    self.backup(cand)
+                } else {
+                    false
+                }
             }
         }
     }
@@ -206,13 +219,12 @@ impl SegmentedAStar {
         Ok(work)
     }
 
-    fn backup(&mut self, cand: &Node, iters: u32) {
+    fn backup(&mut self, cand: &Node) -> bool {
         if self.best().map_or(true, |best| cand.is_better(best)) {
-            tracing::debug!(
-                "{} suggestion @ {iters}: {cand:?}",
-                self.best.map_or("1st", |_| "new")
-            );
             self.best = Some(cand.into());
+            true
+        } else {
+            false
         }
     }