gistfile1.txt

use Test;

sub sorted-merge($lhs, $rhs) {
    my $lhs-list = flat($lhs.list);
    my $rhs-list = flat($rhs.list);
    gather {
        while ?$lhs-list && ?$rhs-list {
            my $a = $lhs-list.shift;
            my $b = $rhs-list.shift;
            if $a == $b {
                take $a;
            } elsif $a < $b {
                take $a;
                $rhs-list.unshift($b);
            } else {
                take $b;
                $lhs-list.unshift($a);
            }
        }
        
        while ?$lhs-list {
            take $lhs-list.shift;
        }
        
        while ?$rhs-list {
            take $rhs-list.shift;
        }
    }
}

multi sub MAIN() {
    my @hamming = (1, 2);
    loop {
        # say "@hamming: " ~ @hamming;
        my $h = @hamming.shift;
        say $h;
        @hamming = sorted-merge(@hamming, ($h * 2, $h * 3, $h * 5));
    }
}

multi sub MAIN("test") {
    is ~sorted-merge(1..10, (3, 5 ... 13)), ~(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13), "merged list correct";
    is ~sorted-merge((3, 5 ... *), 1..5)[^10], ~(1, 2, 3, 4, 5, 7, 9, 11, 13, 15), "merged list correct";
}