class Sass::Script::StringInterpolation

def parse_str(str)
  case str
  when /^unquote\((["'])(.*)\1\)$/
    return true, $1, $2
  when '""'
    return false, nil, ""
  when /^(["'])(.*)\1$/
    return false, $1, $2
  else
    return false, nil, str
  end
end