Task

Select certain elements from an Array into a new Array in a generic way.



To demonstrate, select all even numbers from an Array.

As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.




[ 0 1 2 3 4 5 6 7 8 9 ] as nums
group nums each
    dup 1 & if drop
list as evens