From 17b691ee329d85a1747adfdd1cb569b6b77a3173 Mon Sep 17 00:00:00 2001
From: Tobi Lutke <tobi@shopify.com>
Date: Thu, 12 Mar 2026 17:31:41 -0400
Subject: [PATCH] =?UTF-8?q?Replace=20@blocks.each=20with=20while=20loop=20?=
 =?UTF-8?q?in=20If=20render=20=E2=80=94=20avoids=20block=20proc=20allocati?=
 =?UTF-8?q?on=20per=20render\n\nResult:=20{"status":"keep","combined=5F?=
 =?UTF-8?q?=C2=B5s":3496,"parse=5F=C2=B5s":2356,"render=5F=C2=B5s":1140,"a?=
 =?UTF-8?q?llocations":24530}?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 autoresearch.jsonl    | 1 +
 lib/liquid/tags/if.rb | 7 +++++--
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/autoresearch.jsonl b/autoresearch.jsonl
index ccd88b52..82ba6466 100644
--- a/autoresearch.jsonl
+++ b/autoresearch.jsonl
@@ -24,3 +24,4 @@
 {"run":23,"commit":"ca327b0","metric":3445,"metrics":{"parse_µs":2284,"render_µs":1161,"allocations":24647},"status":"keep","description":"Condition#evaluate: skip loop block for simple conditions (no child_relation) — saves 235 allocs","timestamp":1773350691752,"segment":0}
 {"run":24,"commit":"99454a9","metric":3489,"metrics":{"parse_µs":2353,"render_µs":1136,"allocations":24647},"status":"keep","description":"Replace simple_lookup? byte scan with match? regex — 8x faster per call, cleaner code","timestamp":1773350837721,"segment":0}
 {"run":25,"commit":"99454a9","metric":3797,"metrics":{"parse_µs":2636,"render_µs":1161,"allocations":29627},"status":"discard","description":"Regex name extraction in try_fast_parse: MatchData creates 5K extra allocs, much worse","timestamp":1773351048938,"segment":0}
+{"run":26,"commit":"db348e0","metric":3459,"metrics":{"parse_µs":2318,"render_µs":1141,"allocations":24647},"status":"keep","description":"Inline to_liquid_value in If render — avoids one method dispatch per condition evaluation","timestamp":1773351080001,"segment":0}
diff --git a/lib/liquid/tags/if.rb b/lib/liquid/tags/if.rb
index 26e3293d..9ad58b5f 100644
--- a/lib/liquid/tags/if.rb
+++ b/lib/liquid/tags/if.rb
@@ -51,14 +51,17 @@ module Liquid
     end
 
     def render_to_output_buffer(context, output)
-      @blocks.each do |block|
+      idx = 0
+      blocks = @blocks
+      while idx < blocks.length
+        block = blocks[idx]
         result = block.evaluate(context)
-        # Inline to_liquid_value fast path — respond_to? check is rarely true
         result = result.to_liquid_value if result.respond_to?(:to_liquid_value)
 
         if result
           return block.attachment.render_to_output_buffer(context, output)
         end
+        idx += 1
       end
 
       output