class REXML::Parsers::BaseParser

def parse_id(base_error_message,
             accept_external_id:,
             accept_public_id:)
  if accept_external_id and (md = @source.match(EXTERNAL_ID_PUBLIC, true))
    pubid = system = nil
    pubid_literal = md[1]
    pubid = pubid_literal[1..-2] if pubid_literal # Remove quote
    system_literal = md[2]
    system = system_literal[1..-2] if system_literal # Remove quote
    ["PUBLIC", pubid, system]
  elsif accept_public_id and (md = @source.match(PUBLIC_ID, true))
    pubid = system = nil
    pubid_literal = md[1]
    pubid = pubid_literal[1..-2] if pubid_literal # Remove quote
    ["PUBLIC", pubid, nil]
  elsif accept_external_id and (md = @source.match(EXTERNAL_ID_SYSTEM, true))
    system = nil
    system_literal = md[1]
    system = system_literal[1..-2] if system_literal # Remove quote
    ["SYSTEM", nil, system]
  else
    details = parse_id_invalid_details(accept_external_id: accept_external_id,
                                       accept_public_id: accept_public_id)
    message = "#{base_error_message}: #{details}"
    raise REXML::ParseException.new(message, @source)
  end
end