Hpricot looping with index?

I have the following HTML doc :

<ul>
  <li><span>Some text</span></li>
  <li><span>Some other text</span></li>
  <li><span>Some more text</span></li>
</ul>

How can I use Hpricot to loop on the list items and insert some new HTML at the beginning of each, so that I get the following :

<ul>
  <li><span>1</span><span>Some text</span></li>
  <li><span>2</span><span>Some other text</span></li>
  <li><span>3</span><span>Some more text</span></li>
</ul>

If the new span's content were fixed, I could use :

 (doc/"li").prepend "<span>fixed&开发者_C百科lt;/span>"

My problem comes from the variable span's content : how can I use an index in the prepend loop?

Try this code:

require 'rubygems'
require 'hpricot'

html = <<-EOF
<ul>
  <li><span>Some text</span></li>
  <li><span>Some other text</span></li>
  <li><span>Some more text</span></li>
</ul>
EOF

doc = Hpricot(html)
(doc/'li/span').each_with_index do |element,index|
  value = index + 1
  element.before "<span>#{value}</span>"
end

puts doc.to_s

Use each_child to iterate over each of the li elements, and use a block to increment the index for each iteration.