return func(o *options) { o.checkHyphens = enable }
}

// CheckJoiners sets whether to check the ContextJ rules as defined in Appendix
// A of RFC 5892, concerning the use of joiner runes.
//
// This option corresponds to the CheckJoiners flag in UTS #46.
func CheckJoiners(enable bool) Option {
	return func(o *options) {
		o.trie = trie
		o.checkJoiners = enable
	}
}

	return func(o *options) { o.checkHyphens = enable }
}

// CheckJoiners sets whether to check the ContextJ rules as defined in Appendix
// A of RFC 5892, concerning the use of joiner runes.
//
// This option corresponds to the CheckJoiners flag in UTS #46.
func CheckJoiners(enable bool) Option {
	return func(o *options) {
		o.trie = trie
		o.checkJoiners = enable
	}
}

      "xn--zn7c.com",
      // OkHttp doesn't reject a U+200D. https://www.rfc-editor.org/rfc/rfc5892.html#appendix-A.2
      "xn--1ug.example",
      // OkHttp doesn't implement CheckJoiners.
      "\u200D.example",
      // OkHttp doesn't implement CheckBidi.
      "يa",
    )

  @Test
  fun test() {
    val list = WebPlatformToAsciiData.load()
    val failures = mutableListOf<Throwable>()

    "output": "xn--zca.xn--zca"
  },
  {
    "input": "ab--c.xn--zca",
    "output": "ab--c.xn--zca"
  },
  {
    "input": "ab--c.ß",
    "output": "ab--c.xn--zca"
  },
  {
    "comment": "CheckJoiners is true",
    "input": "\u200D.example",
    "output": null
  },
  {
    "input": "xn--1ug.example",
    "output": null
  },
  {
    "comment": "CheckBidi is true",
    "input": "يa",

  // Must be NFC.
  if (decoded != normalizeNfc(decoded)) return null

  // TODO: Must not begin with a combining mark.
  // TODO: Each character must be 'valid' or 'deviation'. Not mapped.
  // TODO: CheckJoiners from IDNA 2008
  // TODO: CheckBidi from IDNA 2008, RFC 5893, Section 2.

  return Punycode.encode(decoded)