Stubborn emoji won't combine: 👨‍❤‍💋‍👨

Question

Even after @user3441734 solved most of my problems 🙇, there are a few emoji that I can't seem to render properly when converting from a [String:String] to String.

Here's some Playground-ready code to illustrate the problem:

var u = ""
u = "1f468-1f468-1f467-1f467" // 👨‍👨‍👧‍👧
//u = "1f918-1f3ff" // 🤘🏿
//u = "1f468-2764-1f48b-1f468" // 👨‍❤‍💋‍👨 (broken)
//u = "1f3c7-1f3fb" // 🏇‍🏻 (broken)

let unicodeArray = u.characters.split("-")
    .map(String.init)
    .map {String(UnicodeScalar(Int($0,radix: 16) ?? 0))}

if let last = unicodeArray.last {
    let separator: String
    switch (unicodeArray.first, last) {
        // Failed attempt to get tone applied to jockey
    case let (horse_racing, _) where horse_racing == "\u{1f3c7}":
        separator = "\u{200d}"
    case let (_, tone) where "\u{1f3fb}"..."\u{1f3ff}" ~= tone:
        separator = ""
    case let (_, regionalIndicatorSymbol) where "\u{1f1e6}"..."\u{1f1ff}" ~= regionalIndicatorSymbol:
        separator = ""
    default:
        separator = "\u{200d}"
    }
    print(unicodeArray.joinWithSeparator(separator))
}

Uncomment each assignment to u in turn to see the problem in action. The 3rd and 4th values should render like so:

and

Thoughts…

• It turns out that a long-press on the race horse fails to show skin tones on iOS, so let's assume that's just an oversight, perhaps related to the near-impossibility of judging the jockey's skin tone at standard emoji sizes. I still can't figure out the problem with u = "1f468-2764-1f48b-1f468"
• Apologies if this question comes out at all unclear. Chrome and Safari have different behaviors w.r.t these combo-emoji, so only the linked images are guaranteed to appear to you the way I see them on my end. 😢
• These emoji are all either skin-tone renderings or tokens of same-sex affection. Is there some sort of bizarre latent racism & homophobia lurking in the system?! 😱 (Cue the conspiracy theories.)
• Note that my attempt to use the zero-width joiner, u{200d} didn't help.

So, bug in Apple & Chrome's handling of certain emoji, or is there yet another idiosyncrasy of the standard that I've missed?

Answer 1

There's no conspiracy, the bugs are in your code.

• The first character can be produced with:

  U+1F468 U+200D U+2764 U+FE0F U+200D U+1F48B U+200D U+1F468

  Note the ZERO WIDTH JOINER (U+200D) between each character, and the VARIATION SELECTOR-16 selector (U+FE0F) on the HEAVY BLACK HEART (U+2764) to ensure the emoji presentation style is used.

  Refer to this table for a complete list of implemented multi-person groupings.

• U+1F3C7 HORSE RACING is not an emoji modifier base, and so it does not support skin tone modifiers.