class Kramdown::Parser::Kramdown

def replace_abbreviations(el, regexps = nil)
  return if @root.options[:abbrev_defs].empty?
  unless regexps
    sorted_abbrevs = @root.options[:abbrev_defs].keys.sort {|a, b| b.length <=> a.length }
    regexps = [Regexp.union(*sorted_abbrevs.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 = Kramdown::Utils::StringScanner.new(child.value, child.options[:location])
        text_lineno = strscan.current_line_number
        while (temp = strscan.scan_until(regexps.last))
          abbr_lineno = strscan.current_line_number
          abbr = strscan.scan(regexps.first) # begin of line case of abbr with \W char as first one
          if abbr.nil?
            temp << strscan.scan(/\W|^/)
            abbr = strscan.scan(regexps.first)
          end
          result << Element.new(:text, temp, nil, location: text_lineno)
          result << Element.new(:abbreviation, abbr, nil, location: abbr_lineno)
          text_lineno = strscan.current_line_number
        end
        result << Element.new(:text, strscan.rest, nil, location: text_lineno)
      else
        child
      end
    else
      replace_abbreviations(child, regexps)
      child
    end
  end.flatten!
end