gistfile1.builder

# the tags' href is in the form "mm.dd.yy Un-URI-encoded File Title.mp3"

MP3_basename = %r{([^/]+)\.mp3$}

res = doc.css("a").collect do |node|
  begin
    href = node['href']
    title = MP3_basename.match(href)[1].sub(/^(\d\d)\.(\d\d)\.\d\d /,'\1-\2 ')
    node['href'] = "%s/%s" % [BASEHREF, href]
    node.inner_html = Nokogiri::HTML.fragment(title)  # to HTML-encode
    node
  rescue
    nil
  end
end.compact.sort_by {|node| node['href'] }