I added a solution to the dot product, which it turns out was very easy knowing Perl6 meta operators:
[+] ( @a <<*>> @b )
Another problem I worked on is this missing permutations problem, which I solved using cross operators, yet it still doesn't feel that elegant to repeat things four times:
[X~] @letters = @letters X~ @letters X~ @letters X~ @letters
I would've used the [X~] operator, however, it does not seem to work in any implementation yet, so instead I wrote things like on the right hand side, which is quite messy. The only other thing which is sort of interesting is the code to check duplicates. I forget about the uniq function for a while so I wrote this messy code to check for duplicates:
sub lacksDuplicates($str) {
my @chars = $str.split('');
my @pastValues;
for @chars -> $char {
return ?(0) if $char eq any @pastValues;
@pastValues.push($char);
}
return ?(1);
}
Fortunately we have uniq so I wrote something more pleasant instead:
.chars == .split('').uniq.elems
