Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Update SE-0192 for Swift 6 language mode #2450

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

Update SE-0192 for Swift 6 language mode #2450

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 3 additions & 0 deletions proposals/0192-non-exhaustive-enums.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@
* Author: [Jordan Rose](https://github.com/jrose-apple)
* Review Manager: [Ted Kremenek](https://github.com/tkremenek)
* Status: **Implemented (Swift 5.0)**
* Upcoming Feature Flag: `NonfrozenEnumExhaustivity` (implemented in Swift 6.0 to subsume bespoke compiler flag for Swift 4/4.2 language mode)
Copy link
Contributor

@dempseyatgithub dempseyatgithub May 16, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
* Upcoming Feature Flag: `NonfrozenEnumExhaustivity` (implemented in Swift 6.0 to subsume bespoke compiler flag for Swift 4/4.2 language mode)
* Upcoming Feature Flag: `NonfrozenEnumExhaustivity` (implemented in Swift 6.0) (enabled in Swift 6 language mode)

This should also include the (enabled in Swift 6 language mode) annotation to indicate when the flag is always enabled.

The details of what an upcoming feature flag does is not included as part of the header field. The details should be generally be included in the "Source Compatibility" section or elsewhere in the proposal. In this case, in the introduction.

Copy link
Contributor Author

@xwu xwu May 16, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is tricky to explain. It is enabled in Swift 5 language mode too; the flag has no effect except in Swift 4/4.2 mode.

* Implementation: [apple/swift#14945](https://github.com/apple/swift/pull/14945)
* Previous revision: [1](https://github.com/apple/swift-evolution/blob/a773d07ff4beab8b7855adf0ac56d1e13bb7b44c/proposals/0192-non-exhaustive-enums.md), [2 (informal)](https://github.com/jrose-apple/swift-evolution/blob/57dfa2408fe210ed1d5a1251f331045b988ee2f0/proposals/0192-non-exhaustive-enums.md), [3](https://github.com/apple/swift-evolution/blob/af284b519443d3d985f77cc366005ea908e2af59/proposals/0192-non-exhaustive-enums.md)
* Pre-review discussion: [Enums and Source Compatibility](https://forums.swift.org/t/enums-and-source-compatibility/6460), with additional [orphaned thread](https://forums.swift.org/t/enums-and-source-compatibility/6651)
Expand All @@ -21,6 +22,8 @@ A key note: in this version of the proposal, *nothing changes for user-defined S

- Since the proposal was accepted months after it was written, the rollout plan turned out to be a little too aggressive. Therefore, in Swift 5 the diagnostic for omitting `@unknown default:` or `@unknown case _:` will only be a warning, and in Swift 4 mode there will be no diagnostic at all. (The previous version of the proposal used an error and a warning, respectively.) Developers are still free to use `@unknown` in Swift 4 mode, in which case the compiler will still produce a warning if all known cases are not handled.

- To complete the rollout of this feature, the warning is [upgraded to an error for the Swift 6 language mode](https://forums.swift.org/t/amendment-se-0192-handling-future-enum-cases/68321)

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
The upcoming feature flag `NonfrozenEnumExhaustivity` is implemented in Swift 6.0 to subsume the bespoke compiler flag for Swift 4/4.2 language mode.


### Revision at acceptance

Expand Down