memo.rb

require 'nokogiri'

def f node
    node.children.map do |x| 
        [x.name, x.children.size, f(x)]
    end
end

def nodes2text(nodes, level)
    nodes.map { |n|
        "#{"\t"*level}#{n[0]}, #{n[1]}" + nodes2text(n[2], level+1)
    }.reduce(""){|r, x|
        r += "\n" + x
    }
end

html =  Nokogiri::HTML(open('hoge02.htm'));1
nodes = f html;1

text = nodes2text(nodes, 0)
open('hoge2.txt', 'w'){|f| f.puts text}