class Diff::LCS::Hunk

def ed_diff(format)
  op_act = { '+' => 'a', '-' => 'd', '!' => 'c' }
  warn 'Expecting only one block in an old diff hunk!' if @blocks.size > 1
  s =
    if format == :reverse_ed
      encode("#{op_act[@blocks[0].op]}#{context_range(:old)}\n")
    else
      encode("#{context_range(:old, ' ')}#{op_act[@blocks[0].op]}\n")
    end
  unless @blocks[0].insert.empty?
    @data_new[@start_new..@end_new].each do |e| s << e + encode("\n") end
    s << encode(".\n")
  end
  s
end