Efficiency of reading XML documents with relative/absolute addresses

xml_read_efficiency.R

test_xml = '
<div>
  <div>
    <div>
      <div>
        <p>1</p>
        <p>2</p>
        <p>3</p>
      </div>
    </div>
  </div>
</div>
'

library(xml2)
doc = read_xml(test_xml)
sub_doc = xml_find_first(doc, './div/div/div')

ps_from_full = function() {
  o = list(
    xml_find_first(doc, './div/div/div/p[1]'),
    xml_find_first(doc, './div/div/div/p[2]'),
    xml_find_first(doc, './div/div/div/p[3]')
  )
  sapply(o, xml_text)
}
ps_from_sub = function() {
  o = list(
    xml_find_first(sub_doc, './p[1]'),
    xml_find_first(sub_doc, './p[2]'),
    xml_find_first(sub_doc, './p[3]')
  )
  sapply(o, xml_text)
}

bench::mark(ps_from_full(), ps_from_sub())