Sorry, but there was
compactMap functions in
Bindable that should have stayed.
that was what the "// …" was signifying in my post.
Is there an actual priority list to share? Or a way the community can influence the list? Obviously everyone will have slightly different wants from Swift, e.g. I find this to be the highest priority feature to make Swift work how my brain wants it to work, but others value ABI stability first. Is there a gauge on Swift developers' interests, understanding that those who post here are the smallest minority of users?
The priorities and focus area for each release are chosen by the core team. The current priorities (for Swift 5) are documented in the readme for the evolution repo: https://github.com/apple/swift-evolution.
What are the specific issues that need to be designed/addressed?
It may not be at the top of the implementation priority list, but that doesn't mean we can't do actual design work as a community while we wait (and there is always a chance it could piggyback on the implementation of one of the other generics changes, if we are re-writing code anyway).
I can't think of a feature which would do more to relieve coding frustration in Swift. I run into this all the time.
This is a good question. The primary one is what happens to associated types that are not constrained. That is, if I have a
Collection where Element == Int (or however we end up spelling this), what happens when I ask for the
startIndex? If I have two
Comparable values, how does the compiler tell me I still can't use
(The simplest answer to the first question is that you're just not allowed to do this, but that makes
Collection where Element == Int nearly unusable. It's not just indexes you can't get; it's slices and iterators too.)
I really like the design that @Austin drafted a couple years ago. It addresses questions like this starting here. It needs to be updated for the current state of Swift, but otherwise I think it is an excellent place to start. @jrose what is your opinion on the big design decisions made by that draft?