Hi guys.

Apple's Swift as a feature called "Optionals" that makes handling nullable variables a lot easier. While I don't expect an exact port of this feature (as Swift doesn't actually use a null value for nullable values, but instead it all works on top of their Optional enum) there are some syntax niceties that I think we could port. Specifically, their Optional chaining feature.

The syntax I would like is this:

// b is a maybe variable containing an object with a property of c with a type of number
let a = b?.c;

which would equivalent to the flow code:

// b is a maybe variable containing an object with a property of c with a type of number
let a: ?number;
if (b != null) {
    a = b.c;
}

You could chain this almost infinitely.

// d.e is a ?number
let a = b?.c?.d?.e;

which would be equivalent to the flow code

let a: ?number;
if (b != null && b.c != null && b.c.d != null) {
    a = b.c.d.e;
}

I apologise if this has been suggested before.