class Sass::Engine

def parse_mixin_include(line, root)
  name, arg_string = line.text.scan(/^\+\s*([^(]+)(.*)$/).first
  raise SyntaxError.new("Invalid mixin include \"#{line.text}\".", @line) if name.nil?
  offset = line.offset + line.text.size - arg_string.size
  args = Script::Parser.new(arg_string.strip, @line, offset).parse_mixin_include_arglist
  raise SyntaxError.new("Illegal nesting: Nothing may be nested beneath mixin directives.", @line + 1) unless line.children.empty?
  Tree::MixinNode.new(name, args)
end