class SyntaxTree::Words

def format(q)
  opening, closing = "%W[", "]"
  if elements.any? { |element| element.match?(/[\[\]]/) }
    opening = beginning.value
    closing = Quotes.matching(opening[2])
  end
  q.text(opening)
  q.group do
    q.indent do
      q.breakable_empty
      q.seplist(
        elements,
        ArrayLiteral::BREAKABLE_SPACE_SEPARATOR
      ) { |element| q.format(element) }
    end
    q.breakable_empty
  end
  q.text(closing)
end