Comment by ecedeno
12 hours ago
Your example produces very distinguishable results. e.g. if Array.first finds a nil value it returns Optional<Type?>.some(.none), and if it doesn't find any value it returns Optional<Type?>.none
The two are not equal, and only the second one evaluates to true when compared to a naked nil.
What language is this? I'd expect a language with a ? -type would not use an Optional type at all.
In languages such as OCaml, Haskell and Rust this of course works as you say.
This is Swift, where Type? is syntax sugar for Optional<Type>. Swift's Optional is a standard sum type, with a lot of syntax sugar and compiler niceties to make common cases easier and nicer to work with.
Right, so it's not like a union type Type | Null. Then naturally it works the same way as in the languages I listed.