From 81fe6fb6f11e0587bf1434d5c4c3542f4469253d Mon Sep 17 00:00:00 2001
From: "Stanislav (Stas) Katkov" <git@skatkov.com>
Date: Wed, 26 Aug 2026 14:40:20 +0200
Subject: [PATCH] POT serialization optimization (with 87% improvement)

String#+ creates a new string and copies everything accumulated so far. Repeating that for tens of thousands of entries is quadratic.

I replaced the repeated concatenation with one join and results of 400-file build have significantly improved:
- Before: 104.29s
- After: 13.21s
- Improvement: 87.3%
- Output size: identical
- SHA-256: identical
---
 lib/rdoc/generator/pot/po.rb | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/lib/rdoc/generator/pot/po.rb b/lib/rdoc/generator/pot/po.rb
index 447cb60ead..401025f6e8 100644
--- a/lib/rdoc/generator/pot/po.rb
+++ b/lib/rdoc/generator/pot/po.rb
@@ -27,12 +27,7 @@ def add(entry)
   # Returns PO format text for the PO.
 
   def to_s
-    po = ''
-    sort_entries.each do |entry|
-      po += "\n" unless po.empty?
-      po += entry.to_s
-    end
-    po
+    sort_entries.map(&:to_s).join("\n")
   end
 
   private