Replace manual blank_string? with regex match — cleaner code\n\nResult: {"status":"keep","combined_µs":4196,"parse_µs":3042,"render_µs":1154,"allocations":25535}

lib/liquid/block_body.rb

@@ -128,15 +128,10 @@ module Liquid
     PERCENT_BYTE = 37 # '%'.ord
 
     # Fast check if string is whitespace-only (replaces WhitespaceOrNothing regex)
+    BLANK_STRING_REGEX = /\A\s*\z/
+
     def self.blank_string?(str)
-      pos = 0
-      len = str.bytesize
-      while pos < len
-        b = str.getbyte(pos)
-        return false unless b == 32 || b == 9 || b == 10 || b == 13 || b == 12 # space, tab, \n, \r, \f
-        pos += 1
-      end
-      true
+      str.match?(BLANK_STRING_REGEX)
     end
 
     private def parse_for_document(tokenizer, parse_context, &block)