Solution: nil. Problem: How do you tell the difference between "the array was empty" and "the item you popped was nil"?
Solution: have pop return a Maybe instead.
{ has_value: bool,
val: T|nil }
{has_value: true, val: nil}
Maybe<T> =
sigma (has_value: bool)
if has_value
then T
else ()
(false, ())
(true, <actual value of type T>)or a whole value
or use an enumerator
or a collection decorator
All of which are simple solutions already available. No need to import every new paradigm hammer in the hope that everything is a nail.
It’s great in large scale projects, which I think is where a dynamic language starts to show its warts.
Never manually do the work that the compiler / runtime could do.
You can design "more thoughtfully designing your data/object model" (in other regards) AND have the compiler make sure you're not doing null referencing for you (so that that's not your concern anymore) -- instead of manually and in an ad-hoc way per project implementing another menial responsibility into the design of your model.