bench.rb

require "benchmark"

require "rexml/document"

n = 10000

xml = REXML::Document.new(<<~XML)
  <?xml version="1.0" encoding="UTF-8"?>
  <breakfast_menu>
  <food>
      <name>Belgian Waffles</name>
      <price>$5.95</price>
      <description>
     Two of our famous Belgian Waffles with plenty of real maple syrup
     </description>
      <calories>650</calories>
  </food>
  <food>
      <name>Strawberry Belgian Waffles</name>
      <price>$7.95</price>
      <description>
      Light Belgian waffles covered with strawberries and whipped cream
      </description>
      <calories>900</calories>
  </food>
  <food>
      <name>Berry-Berry Belgian Waffles</name>
      <price>$8.95</price>
      <description>
      Belgian waffles covered with assorted fresh berries and whipped cream
      </description>
      <calories>900</calories>
  </food>
  <food>
      <name>French Toast</name>
      <price>$4.50</price>
      <description>
      Thick slices made from our homemade sourdough bread
      </description>
      <calories>600</calories>
  </food>
  <food>
      <name>Homestyle Breakfast</name>
      <price>$6.95</price>
      <description>
      Two eggs, bacon or sausage, toast, and our ever-popular hash browns
      </description>
      <calories>950</calories>
  </food>
  </breakfast_menu>
  XML

def my_each_recursive(element, &)
  element.each_child do |child|
    next unless child.is_a?(REXML::Element)
    yield child
    my_each_recursive(child, &)
  end
end

es1 = []
xml.each_recursive { es1 << _1 }
es2 = []
my_each_recursive(xml) { es2 << _1 }

raise "invalid implementation" unless es1 == es2

Benchmark.bm do |x|
  x.report("   each_recursive") { n.times { xml.each_recursive { } } }
  x.report("my_each_recursive") { n.times { my_each_recursive(xml) { } } }
end