--- self[name]

    name бåɤ˸ͭΥǡФ
    name ʸ Symbol ǻꤷޤ

    name б륹åɸͭǡʤ nil ֤
    ޤ

--- self[name] = val

    val  name б륹åɸͭΥǡȤƳǼ
    ޤname ʸ Symbol ǻꤷޤ
    val  nil ꤹȤΥåɸͭǡϺ
    ޤ

    val ֤ޤ

