Hmm, I meant this line of the OP's code:
my @nums = $data =~ /\d+/g;
I think it can be called an assignment to an array, which imposes a list context on the right-hand side, as it is described in perldata:
Assignment to a scalar evaluates the right-hand side in scalar context, while assignment to an array
or hash evaluates the righthand side in list context. Assignment to a list
(or slice, which is just a list anyway) also evaluates the righthand side
in list context.
I think this would be an assignment to a list:
my ($num) = ...