From 61dd31f4c4c1ccb6a9d7185e51cd040f4c61fea3 Mon Sep 17 00:00:00 2001
From: Tommy Volk <tvolk131@gmail.com>
Date: Sun, 25 Oct 2026 18:13:29 -0500
Subject: [PATCH] perf(encoding): reuse one program traversal

Collect postorder entries once to obtain the node count and encode the same entries, avoiding repeated traversal and sharing-map work at the cost of temporary node storage.

Written by OpenAI Codex.
---
 src/bit_encoding/encode.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/bit_encoding/encode.rs b/src/bit_encoding/encode.rs
index e7cff1f1..f4c812a0 100644
--- a/src/bit_encoding/encode.rs
+++ b/src/bit_encoding/encode.rs
@@ -157,13 +157,13 @@ pub fn encode_program<N: node::Marker>(
     program: &node::Node<N>,
     w: &mut BitWriter<&mut dyn io::Write>,
 ) -> io::Result<usize> {
-    let iter = EncodeNode::Node(program).post_order_iter::<EncodeSharing<N>>();
-
-    let len = iter.clone().count();
+    let nodes: Vec<_> = EncodeNode::Node(program)
+        .post_order_iter::<EncodeSharing<N>>()
+        .collect();
     let n_start = w.n_total_written();
-    encode_natural(len, w)?;
+    encode_natural(nodes.len(), w)?;
 
-    for node in iter {
+    for node in nodes {
         encode_node(node, w)?;
     }