「人種のるつぼ」ネタをtwitterで見かけて、つい

FamiliEmojis.cs

using static System.Linq.Enumerable;

var parentals = new[] { "👩", "👨" };
var infants = new[] { "👦", "👧" };
var skinTones = new[] { "🏻", "🏼", "🏽", "🏾", "🏿" };
const char zwj = '\u200D';

var families =
    from a in from f in parentals from s in skinTones select f + s
    from b in from f in parentals from s in skinTones select f + s
    from c in from f in infants from s in skinTones select f + s
    from d in from f in infants from s in skinTones select f + s
    select a + zwj + b + zwj + c + zwj + d;

foreach (var f in families)
{
    Console.Write(f);
}

ZwjEmoji.cs

using System.Collections.Generic;
using System.Linq;
using static System.Console;

static IEnumerable<T> Times<T>(this int n, T item) => Enumerable.Range(0, n).Select(_ => item);
static string MakeFamily(this IEnumerable<string> faces) => string.Join("\u200D", faces);

// いくつでもくっつく
WriteLine(10.Times("👩").MakeFamily());
WriteLine(10.Times("👨").MakeFamily());
// くっつかない！(グリフとしてはくっつかないけど、ZWJ 挟まってるのでエディターによってはカーソル移動1回扱い)
WriteLine(10.Times("👧").MakeFamily());
WriteLine(10.Times("👦").MakeFamily());

// 親の後ろに子供はくっつく(逆はダメ)
WriteLine(10.Times("👩").Append("👧").MakeFamily());
// 親、親、子、子はくっつく
WriteLine(new[] { "👩", "👩", "👧", "👧" }.MakeFamily());
// 子の後ろにはもうくっつかない
WriteLine(new[] { "👩", "👧", "👧", "👩" }.MakeFamily());
WriteLine(new[] { "👧", "👩", "👧", "👩" }.MakeFamily());
// でもなぜか、親、子、親、子の順だとくっつく (2家族作られて、それがさらにくっついてるんだと思う)
WriteLine(new[] { "👩", "👧", "👩", "👧" }.MakeFamily());

// 子供がくっつくのは2人まで(でも、3人目以降も小さくなる)
WriteLine(new[] { "👩", "👩", "👧" }.MakeFamily());
WriteLine(new[] { "👩", "👩", "👧", "👧" }.MakeFamily());
WriteLine(new[] { "👩", "👩", "👧", "👧", "👧" }.MakeFamily());
WriteLine(new[] { "👩", "👩", "👧", "👧", "👧", "👧" }.MakeFamily());