Optional Return

Evolution Pitches
1

I don't know if this idea has surfaced before, but I've found myself doing this way too often:

func foo(_ value: Int?) -> Int {
    if let value = value {
        return value
    }
    // Do something else...
}

I wonder, if this syntax sugar is something that Swift would benefit from:

func foo(_ value: Int?) -> Int {
    return? value
    // Do something else...
}

The return? statement takes an expression of type R? where R is the return type of the enclosing function and returns if and only if the expression is not nil.

This would be particularly useful in combination with optional chaining:

func foo(_ value: Int?) -> String {
    return? value.map { "\($0)" }
    // Do something else...
}

What do you guys think?

1 Like
2

Implicit control flow around return seems like a great source of bugs. Remember gotofail.

3 Likes
3

I‘ve never used nor seen this pattern before. I don‘t consider that as a valid motivation for opposition, but afaics, you can easily avoid the boilerplate:

let fooResult = optionalValue ?? foo()

What‘s wrong with doing it this way?

4

Yet it does: SE-0231 — Optional iteration - #38 by gwendal.roue :wink: