class Rufo::Formatter

def visit_for(node)
  #[:for, var, collection, body]
  _, var, collection, body = node
  consume_keyword "for"
  consume_space
  if var[0].is_a?(Symbol)
    visit var
  else
    visit_comma_separated_list var
  end
  consume_space
  consume_keyword "in"
  consume_space
  visit collection
  skip_space
  next_token if keyword?("do")
  indent_body body
  write_indent
  consume_keyword "end"
end