class YARD::Docstring

def summary
  resolve_reference
  return @summary if defined?(@summary) && @summary
  stripped = gsub(/[\r\n](?![\r\n])/, ' ').strip
  num_parens = 0
  idx = length.times do |index|
    case stripped[index, 1]
    when "."
      next_char = stripped[index + 1, 1].to_s
      break index - 1 if num_parens <= 0 && next_char =~ /^\s*$/
    when "\r", "\n"
      next_char = stripped[index + 1, 1].to_s
      if next_char =~ /^\s*$/
        break stripped[index - 1, 1] == '.' ? index - 2 : index - 1
      end
    when "{", "(", "["
      num_parens += 1
    when "}", ")", "]"
      num_parens -= 1
    end
  end
  @summary = stripped[0..idx]
  if !@summary.empty? && @summary !~ /\A\s*\{include:.+\}\s*\Z/
    @summary += '.'
  end
  @summary
end