class Kramdown::Parser::Kramdown

def replace_abbreviations(el, regexps = nil)
  return if @root.options[:abbrev_defs].empty?
  if !regexps
    regexps = [Regexp.union(*@root.options[:abbrev_defs].keys.map {|k| /#{Regexp.escape(k)}/})]
    regexps << /(?=(?:\W|^)#{regexps.first}(?!\w))/ # regexp should only match on word boundaries
  end
  el.children.map! do |child|
    if child.type == :text
      if child.value =~ regexps.first
        result = []
        strscan = StringScanner.new(child.value)
        while temp = strscan.scan_until(regexps.last)
          temp << strscan.scan(/\W|^/)
          abbr = strscan.scan(regexps.first)
          result << Element.new(:text, temp) << Element.new(:abbreviation, abbr)
        end
        result << Element.new(:text, strscan.rest)
      else
        child
      end
    else
      replace_abbreviations(child, regexps)
      child
    end
  end.flatten!
end