Hi Everybody,
With another round of apologies for taking late action, we propose to
make some deprecations, moves, and renames. The background for these
moves is as follows:We've always known that when Swift reached ABI stability (now slated for
Swift 4), we would be committed to supporting many of the standard
library's design decisions for years to come. What we only realized
very recently is that, although Swift 3.0 is *not* shipping with a
stable ABI, the promise that Swift 3.0 code will work with Swift 4.0
code creates similar implications when it comes to certain protocols,
today. Especially where these protocols show up in refinement
hierarchies, we can't keep Swift 3 code working in the future without
carrying them forward into future libraries.The proposed changes are as follows:
* Move `CustomPlaygroundQuickLookable` to the PlaygroundSupport module.
This component is really only useful for playgrounds, and doesn't
belong in the standard library.I didn't think it was possible to `import PlaygroundSupport` unless the
current file is within a playground. If so, how can corelibs-foundation
or third-party modules add `CustomPlaygroundQuickLookable`
conformance?Ahhh... yeah, I didn't realize that, and we don't have time to change
that restriction for Swift 3. It's not a problem for
corelibs-foundation but it would be for 3rd-party libraries.OK, Dmitri and I just figured out how we can change the home of these
types for Swift 4 without breaking Swift 3 code (mirrors to the rescue!)
So I'm going to withdraw this part of the proposal.Will the following need to be reverted?
<https://github.com/apple/swift/pull/4089>
<https://github.com/apple/swift-xcode-playground-support/commit/aab7af4>
<https://github.com/apple/swift-xcode-playground-support/commit/865fd0c>
<https://github.com/apple/swift-xcode-playground-support/commit/ab605ef>
<https://github.com/apple/swift-xcode-playground-support/commit/4bd6575>
<https://github.com/apple/swift-xcode-playground-support/commit/acee2e1>
Technically, no, because typealiases make it unnecessary, but yes, we
plan to do that.
* Deprecate the Indexable protocols with a message indicating that they
will be gone in Swift 4. These protocols are implementation details
of the standard library designed to work around language limitations
that we expect to be gone in Swift 4. There's no reason for anyone to
ever touch these; users should always use a corresponding Collection
protocol (e.g. instead of MutableIndexable, use MutableCollection).* Deprecate the ExpressibleByStringInterpolation protocol with a
message indicating that its design is expected to change. We know
this protocol to be mis-designed
(https://bugs.swift.org/browse/SR-1260\) and limited
(https://bugs.swift.org/browse/SR-2303\), but there's no time to fix it
for Swift 3. If we knew what the new design should look like, we
might be able to calculate that the current API is supportable in a
forward-compatible way (as we do for Comparable). Unfortunately, we
do not.* Rename Streamable to TextOutputStreamable and add a deprecated
Streamable typealias for it. Now that OutputStream been renamed to
TextOutputStream, we should also move Streamable out of the way.In apple/swift#4131, these lines have overrun the 80 column limit:
<https://github.com/apple/swift/blob/f2443f4/stdlib/public/core/Mirror.swift#L843>
<https://github.com/apple/swift/blob/f2443f4/stdlib/public/core/Mirror.swift#L893><https://github.com/apple/swift/blob/f2443f4/stdlib/public/core/Print.swift#L177>
<https://github.com/apple/swift/blob/f2443f4/stdlib/public/core/Print.swift#L228>TextFormatting.rst also needs `Streamable` => `TextOutputStreamable`:
<https://github.com/apple/swift/blob/master/docs/TextFormatting.rst>
Pull requests gratefully accepted for all of these corrections
Deprecation is being proposed instead of underscoring or renaming
because it allows existing code to keep working (with warnings). At
this late stage, it would be bad to actually break anything.If the SE-0104 (protocol-oriented integers) proposal has been deferred,
should any protocols (e.g. SignedNumber) be deprecated?Will the SE-0104 proposal be accepted for Swift 4.0?
It is expected to be. We may even be able to get it into a Swift 3
point-release (e.g. 3.1)
···
on Wed Aug 10 2016, Ben Rimmington <me-AT-benrimmington.com> wrote:
On 10 Aug 2016, at 00:36, Dave Abrahams wrote:
on Tue Aug 09 2016, Ben Rimmington wrote:
On 9 Aug 2016, at 20:09, Dave Abrahams wrote:
--
Dave
'StringInterpolationConvertible' is deprecated:
Fix-it: Use 'ExpressibleByStringInterpolation' instead