class Crass::Parser

def consume_rules(flags = {})
  rules = []
  while token = @tokens.consume
    case token[:node]
      # Non-standard. Spec says to discard comments and whitespace, but we
      # keep them so we can serialize faithfully.
    when :comment, :whitespace
      rules << token
    when :cdc, :cdo
      unless flags[:top_level]
        @tokens.reconsume
        rule = consume_qualified_rule
        rules << rule if rule
      end
    when :at_keyword
      @tokens.reconsume
      rule = consume_at_rule
      rules << rule if rule
    else
      @tokens.reconsume
      rule = consume_qualified_rule
      rules << rule if rule
    end
  end
  rules
end