P21 - Insert an element at a given position into a list.
Author: Ryan Connelly
Example
> say insert-at('alfa', <a b c d>, 2); a alfa b c d
Source code: P21-topo.pl
use v6; sub insert-at($elem, @list is copy, $place) { @list.splice($place - 1, 0, $elem); @list } say "{insert-at('alfa', <a b c d>, 2)}";