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.




filter pred lst:
	]
	for value in copy lst:
		if pred @value:
			@value
	[
 
even x:
	= 0 % x 2
 
!. filter @even [ 0 1 2 3 4 5 6 7 8 9 ]