class Kramdown::Parser::GFM

def update_raw_text(item)
  raw_text = ''
  append_text = lambda do |child|
    if child.type == :text || child.type == :codespan || child.type ==:math
      raw_text << child.value
    elsif child.type == :entity
      raw_text << child.value.char
    elsif child.type == :smart_quote
      raw_text << ::Kramdown::Utils::Entities.entity(child.value.to_s).char
    elsif child.type == :typographic_sym
      if child.value == :laquo_space
        raw_text << "« "
      elsif child.value == :raquo_space
        raw_text << " »"
      else
        raw_text << ::Kramdown::Utils::Entities.entity(child.value.to_s).char
      end
    else
      child.children.each {|c| append_text.call(c)}
    end
  end
  append_text.call(item)
  item.options[:raw_text] = raw_text
end