[swift-evolution] [Review #2] SE-0117: Default classes to be non-subclassable publicly

[David Waite]

> 	https://github.com/apple/swift-evolution/blob/master/proposals/0117-non-public-subclassable-by-default.md
> 
> 	* What is your evaluation of the proposal?

+1

I don’t necessarily like the idea of sealed-by-default overridability of members, although I will admit it goes along well with the general philosophy of reducing the need for modifiers on internal API. I would prefer final-by-default, and the final keyword being removed.

I did not see anything within the proposal, but I assume that overridability of initializers was evaluated and deemed sufficient with existing mechanisms?

> 	* Is the problem being addressed significant enough to warrant a change to Swift?
Yes
> 	* Does this proposal fit well with the feel and direction of Swift?
Generally yes
> 	* If you have used other languages or libraries with a similar feature, how do you feel that this proposal compares to those?
Sure, I would say C# follows this reasonably well with its virtual keyword, although I don’t believe they are sealed by default at the class level

> 	* How much effort did you put into your review? A glance, a quick reading, or an in-depth study?

Followed most of comments, In-depth study

-DW