OptionParser::Switch#summarize

# File tmp/rubies/ruby-3.2.0/lib/optparse.rb, line 603
def summarize(sdone = {}, ldone = {}, width = 1, max = width - 1, indent = "")
  sopts, lopts = [], [], nil
  @short.each {|s| sdone.fetch(s) {sopts << s}; sdone[s] = true} if @short
  @long.each {|s| ldone.fetch(s) {lopts << s}; ldone[s] = true} if @long
  return if sopts.empty? and lopts.empty? # completely hidden

  left = [sopts.join(', ')]
  right = desc.dup

  while s = lopts.shift
    l = left[-1].length + s.length
    l += arg.length if left.size == 1 && arg
    l < max or sopts.empty? or left << +''
    left[-1] << (left[-1].empty? ? ' ' * 4 : ', ') << s
  end

  if arg
    left[0] << (left[1] ? arg.sub(/\A(\[?)=/, '\1') + ',' : arg)
  end
  mlen = left.collect {|ss| ss.length}.max.to_i
  while mlen > width and l = left.shift
    mlen = left.collect {|ss| ss.length}.max.to_i if l.length == mlen
    if l.length < width and (r = right[0]) and !r.empty?
      l = l.to_s.ljust(width) + ' ' + r
      right.shift
    end
    yield(indent + l)
  end

  while begin l = left.shift; r = right.shift; l or r end
    l = l.to_s.ljust(width) + ' ' + r if r and !r.empty?
    yield(indent + l)
  end

  self
end