gistfile1.txt

    my atomicint $spawn-limit = 8;
    multi sub spawn(&c, |args) {
        # dd ⚛$spawn-limit;
        ⚛$spawn-limit > 0
            ?? ($spawn-limit⚛-- ;start { LEAVE $spawn-limit⚛++; c(|args) })
            !! c(|args)
    }

    sub collect(*@things) {
       slip @things.map: -> $thing { $thing ~~ Promise ?? await $thing !! $thing }
    }

    # multi quicksort([]) { () }
    multi quicksort(*@empty where @empty ~~ ()) { () }
    multi quicksort(*@rest) {
        my $pivot = shift @rest;
        my @before = @rest.grep(* before $pivot);
        my @after  = @rest.grep(* !before $pivot);

        flat collect spawn(&?ROUTINE.dispatcher, @before), $pivot, spawn(&?ROUTINE.dispatcher, @after)
    }

    my @a = ('a'..'z').roll(12).join xx 2**16;
    # dd @a;
    # say quicksort @a;