From 274f07880604576c745e431a3e41d6fe97bede43 Mon Sep 17 00:00:00 2001
From: Richard Monette <richard.monette@shopify.com>
Date: Tue, 12 Mar 2019 17:28:16 -0400
Subject: [PATCH] defer hash allocation in parse_filter_expressions

add exploration of GC object allocation

remove performance test

can actually remove one more if branch

use named locals to improve readability
---
 lib/liquid/variable.rb | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/lib/liquid/variable.rb b/lib/liquid/variable.rb
index c31bffe5..717b1a2a 100644
--- a/lib/liquid/variable.rb
+++ b/lib/liquid/variable.rb
@@ -95,16 +95,17 @@ module Liquid
 
     def parse_filter_expressions(filter_name, unparsed_args)
       filter_args = []
-      keyword_args = {}
+      keyword_args = nil
       unparsed_args.each do |a|
         if matches = a.match(JustTagAttributes)
+          keyword_args ||= {}
           keyword_args[matches[1]] = Expression.parse(matches[2])
         else
           filter_args << Expression.parse(a)
         end
       end
       result = [filter_name, filter_args]
-      result << keyword_args unless keyword_args.empty?
+      result << keyword_args if keyword_args
       result
     end