End of source-breaking changes for Swift 3

Apologies if this was announced elsewhere: is commit access to master restricted?

It was, for about a day. It's less-restricted now, but there's a special process that doesn't have an exception for things like documentation because it's being enforced by automated tools.

The announcement is on swift-dev.

John.

···

On Jul 28, 2016, at 8:30 AM, Brian Gesiak <modocache@gmail.com> wrote:

I noticed I couldn't merge some documentation improvements in [SourceKit] Add documentation for SourceKit request types by RLovelett · Pull Request #3815 · apple/swift · GitHub, and just wanted to make sure this was due to Swift 3 finalization.

If commit access is restricted, is it safe to assume that restriction will be lifted on or around July 29?

- Brian Gesiak

On Thu, Jul 28, 2016 at 7:15 AM, Anton Zhilin via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote:
Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub
Is SE-0077 going to be implemented for Swift 3?

https://github.com/apple/swift/blob/master/stdlib/internal/SwiftExperimental/SwiftExperimental.swift
Does this code actually run?

If so, I will add "implemented" to the proposal, plus I still haven't added latest naming changes. ¯\_(ツ)_/¯

2016-07-28 1:17 GMT+03:00 Tony Allevato via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>>:
I noticed that while SE-0091 appears to be implemented (from a cursory glance at some of the affected types like Equatable and String), it looks like the named methods are still part of the FloatingPoint protocol and they still use global operators.

Is anyone tracking the migration of that protocol (and possibly also the new Integer protocols) to use the new operator technique? (I have to apologize for not being able to update the proposal with another PR that listed all those changes—my free time outside my day job has been significantly reduced lately.)

On Wed, Jul 27, 2016 at 12:38 PM Ted Kremenek via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote:
Dear friends,

Today is July 27 — and the last planned day to take source-breaking changes for Swift 3. It has been an incredible ride to this point, so let's take stock of where we are. Here are the list of currently accepted — but not yet (fully) implemented — evolution proposals (this is drawn from the "accepted" but not marked "implemented" proposals from the swift-evolution <https://github.com/apple/swift-evolution&gt; repository):

SE-0025 - Scoped Access Level <https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md&gt;
SE-0042 - Flattening the function type of unapplied method references <https://github.com/apple/swift-evolution/blob/master/proposals/0042-flatten-method-types.md&gt;
SE-0045 - Add scan, prefix(while:), drop(while:), and iterate to the stdlib <https://github.com/apple/swift-evolution/blob/master/proposals/0045-scan-takewhile-dropwhile.md&gt;
SE-0068 - Expanding Swift Self to class members and value types <https://github.com/apple/swift-evolution/blob/master/proposals/0068-universal-self.md&gt;
SE-0075 - Adding a Build Configuration Import Test <https://github.com/apple/swift-evolution/blob/master/proposals/0075-import-test.md&gt;
SE-0077 - Improved operator declarations <https://github.com/apple/swift-evolution/blob/master/proposals/0077-operator-precedence.md&gt;
SE-0080 - Failable Numeric Conversion Initializers <https://github.com/apple/swift-evolution/blob/master/proposals/0080-failable-numeric-initializers.md&gt;
SE-0081 - Move where clause to end of declaration <https://github.com/apple/swift-evolution/blob/master/proposals/0081-move-where-expression.md&gt;
SE-0082 - Package Manager Editable Packages <https://github.com/apple/swift-evolution/blob/master/proposals/0082-swiftpm-package-edit.md&gt;
SE-0088 - Modernize libdispatch for Swift 3 naming conventions <https://github.com/apple/swift-evolution/blob/master/proposals/0088-libdispatch-for-swift3.md&gt;
SE-0089 - Renaming String.init<T>(_: T) <https://github.com/apple/swift-evolution/blob/master/proposals/0089-rename-string-reflection-init.md&gt;
SE-0092 - Typealiases in protocols and protocol extensions <https://github.com/apple/swift-evolution/blob/master/proposals/0092-typealiases-in-protocols.md&gt;
SE-0096 - Converting dynamicType from a property to an operator <https://github.com/apple/swift-evolution/blob/master/proposals/0096-dynamictype.md&gt;
SE-0099 - Restructuring Condition Clauses <https://github.com/apple/swift-evolution/blob/master/proposals/0099-conditionclauses.md&gt;
SE-0101 - Reconfiguring sizeof and related functions into a unified MemoryLayout struct <https://github.com/apple/swift-evolution/blob/master/proposals/0101-standardizing-sizeof-naming.md&gt;
SE-0102 - Remove @noreturn attribute and introduce an empty Never type <https://github.com/apple/swift-evolution/blob/master/proposals/0102-noreturn-bottom-type.md&gt;
SE-0103 - Make non-escaping closures the default <https://github.com/apple/swift-evolution/blob/master/proposals/0103-make-noescape-default.md&gt;
SE-0104 - Protocol-oriented integers <https://github.com/apple/swift-evolution/blob/master/proposals/0104-improved-integers.md&gt;
SE-0107 - UnsafeRawPointer API <https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md&gt;
SE-0110 - Distinguish between single-tuple and multiple-argument function types <https://github.com/apple/swift-evolution/blob/master/proposals/0110-distingish-single-tuple-arg.md&gt;
SE-0111 - Remove type system significance of function argument labels <https://github.com/apple/swift-evolution/blob/master/proposals/0111-remove-arg-label-type-significance.md&gt;
SE-0120 - Revise partition Method Signature <https://github.com/apple/swift-evolution/blob/master/proposals/0120-revise-partition-method.md&gt;
SE-0127 - Cleaning up stdlib Pointer and Buffer Routines <https://github.com/apple/swift-evolution/blob/master/proposals/0127-cleaning-up-stdlib-ptr-buffer.md&gt;
These are all changes the community has approved for Swift but did not make today's cutoff. Some of these proposals have implementations actively underway. For those proposals already in active development — and near completion — I am okay with extending the deadline for those changes to Friday, July 29. Such changes need to be approved by the release manager (myself) and should be merged into master via a pull request. When creating the pull request, please assign it to me (tkremenek), and mention the pull request on the swift-dev mailing list as well with the SE number in the email title.

The rest of the unimplemented proposals do not make Swift 3. This leaves us with the question of what to do with them. These proposals represent the known and reviewed changes we want to make to Swift, but inevitably there will also be changes that we don't even know about today that we will want to take into Swift that can impact core source stability. That said, we also have a very strong desire to maintain source compatibility with Swift 3 and Swift 4 as much as possible to provide some stability for which Swift users to build upon. The challenge of course is reconciling these diametrically opposing goals: maintaining source stability while having the ability to incorporate more core (and important) language changes that are possibly source-breaking.

The Swift team at Apple has reflected on this and decided what it "means" for Swift 3 to be source compatible with Swift 4 and later releases going forward. Our goal is to allow app developers to combine a mix of Swift modules (e.g., SwiftPM packages), where each module is known to compile with a specific version of the language (module A works with Swift 3, module B works with Swift 3.1, etc.), then combine those modules into a single binary. The key feature is that a module can be migrated from Swift 3 to 3.1 to 4 (and beyond) independently of its dependencies.

While the exact details of how we will accomplish this feat are still being discussed, here is a sketch of how this will likely work in the Swift 4 timeframe. The key enabler is a new compiler flag that indicates the language version to compile for (e.g., similar to the clang -std=c99 flag). The compiler flag will be provided by the build system you are using (e.g., Xcode, SwiftPM, etc.) on a per-module basis:

For language syntax/semantics, the compiler can use the language mode to properly implement the language version being used by a module.

For the Standard Library, additive and subtractive changes are easily handled (the former by just adding them, the later by using deprecation techniques). For semantics changes, things are much more complicated, and will need further study.

The great thing about this approach is that a single Swift 4 compiler is building all of the sources in an application. This allows us to roll out this approach before achieving full ABI stability — something that will be a goal for Swift 4, but is impractical to achieve for a Swift 3.x release. It also provides us a general framework in the future for handling source compatibility as Swift evolves.

To make this more concrete, suppose an application is written to use Swift 4, but uses packages via SwiftPM that are written using Swift 3. A single compiler would build both the app and the packages — thus ensuring that all the compiled sources are binary compatible. It would not be the case that a framework built with the Swift 3 compiler could be used by an app built using the Swift 4 compiler. That kind of library binary stability (ABI) will be a key goal of the Swift 4 release.

These constraints mentioned above will serve as scaffolding for Swift 4 development. Discussion about Swift 4 commences on Monday. Ahead of that, Chris Lattner plans to send out thoughts from the Core team on some of the known key goals (and non-goals) for the release. In the meantime, the focus over the next couple days should be taking stock of what has landed for Swift 3 and to see if any of the proposals mentioned above are close to being completed or are truly out of scope.

Thank you again to everyone for making Swift 3 such as fantastic release!

Ted

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org <mailto:swift-evolution@swift.org>
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org <mailto:swift-evolution@swift.org>
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org <mailto:swift-evolution@swift.org>
https://lists.swift.org/mailman/listinfo/swift-evolution

Apologies if this was announced elsewhere: is commit access to master
restricted?

I noticed I couldn't merge some documentation improvements in
[SourceKit] Add documentation for SourceKit request types by RLovelett · Pull Request #3815 · apple/swift · GitHub, and just wanted to make sure this
was due to Swift 3 finalization.

If commit access is restricted, is it safe to assume that restriction will
be lifted on or around July 29?

- Brian Gesiak

···

On Thu, Jul 28, 2016 at 7:15 AM, Anton Zhilin via swift-evolution < swift-evolution@swift.org> wrote:

Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub
Is SE-0077 going to be implemented for Swift 3?

https://github.com/apple/swift/blob/master/stdlib/internal/SwiftExperimental/SwiftExperimental.swift
Does this code actually run?

If so, I will add "implemented" to the proposal, plus I still haven't
added latest naming changes. ¯\_(ツ)_/¯

2016-07-28 1:17 GMT+03:00 Tony Allevato via swift-evolution <
swift-evolution@swift.org>:

I noticed that while SE-0091 appears to be implemented (from a cursory
glance at some of the affected types like Equatable and String), it looks
like the named methods are still part of the FloatingPoint protocol and
they still use global operators.

Is anyone tracking the migration of that protocol (and possibly also the
new Integer protocols) to use the new operator technique? (I have to
apologize for not being able to update the proposal with another PR that
listed all those changes—my free time outside my day job has been
significantly reduced lately.)

On Wed, Jul 27, 2016 at 12:38 PM Ted Kremenek via swift-evolution < >> swift-evolution@swift.org> wrote:

Dear friends,

Today is July 27 — and the last planned day to take source-breaking
changes for Swift 3. It has been an incredible ride to this point, so let's
take stock of where we are. Here are the list of currently accepted — but
not yet (fully) implemented — evolution proposals (this is drawn from the
"accepted" but not marked "implemented" proposals from the
swift-evolution <https://github.com/apple/swift-evolution&gt; repository):

   - SE-0025 - Scoped Access Level
   <https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md&gt;
   - SE-0042 - Flattening the function type of unapplied method
   references
   <https://github.com/apple/swift-evolution/blob/master/proposals/0042-flatten-method-types.md&gt;
   - SE-0045 - Add scan, prefix(while:), drop(while:), and iterate to
   the stdlib
   <https://github.com/apple/swift-evolution/blob/master/proposals/0045-scan-takewhile-dropwhile.md&gt;
   - SE-0068 - Expanding Swift Self to class members and value types
   <https://github.com/apple/swift-evolution/blob/master/proposals/0068-universal-self.md&gt;
   - SE-0075 - Adding a Build Configuration Import Test
   <https://github.com/apple/swift-evolution/blob/master/proposals/0075-import-test.md&gt;
   - SE-0077 - Improved operator declarations
   <https://github.com/apple/swift-evolution/blob/master/proposals/0077-operator-precedence.md&gt;
   - SE-0080 - Failable Numeric Conversion Initializers
   <https://github.com/apple/swift-evolution/blob/master/proposals/0080-failable-numeric-initializers.md&gt;
   - SE-0081 - Move where clause to end of declaration
   <https://github.com/apple/swift-evolution/blob/master/proposals/0081-move-where-expression.md&gt;
   - SE-0082 - Package Manager Editable Packages
   <https://github.com/apple/swift-evolution/blob/master/proposals/0082-swiftpm-package-edit.md&gt;
   - SE-0088 - Modernize libdispatch for Swift 3 naming conventions
   <https://github.com/apple/swift-evolution/blob/master/proposals/0088-libdispatch-for-swift3.md&gt;
   - SE-0089 - Renaming String.init<T>(_: T)
   <https://github.com/apple/swift-evolution/blob/master/proposals/0089-rename-string-reflection-init.md&gt;
   - SE-0092 - Typealiases in protocols and protocol extensions
   <https://github.com/apple/swift-evolution/blob/master/proposals/0092-typealiases-in-protocols.md&gt;
   - SE-0096 - Converting dynamicType from a property to an operator
   <https://github.com/apple/swift-evolution/blob/master/proposals/0096-dynamictype.md&gt;
   - SE-0099 - Restructuring Condition Clauses
   <https://github.com/apple/swift-evolution/blob/master/proposals/0099-conditionclauses.md&gt;
   - SE-0101 - Reconfiguring sizeof and related functions into a
   unified MemoryLayout struct
   <https://github.com/apple/swift-evolution/blob/master/proposals/0101-standardizing-sizeof-naming.md&gt;
   - SE-0102 - Remove @noreturn attribute and introduce an empty Never
    type
   <https://github.com/apple/swift-evolution/blob/master/proposals/0102-noreturn-bottom-type.md&gt;
   - SE-0103 - Make non-escaping closures the default
   <https://github.com/apple/swift-evolution/blob/master/proposals/0103-make-noescape-default.md&gt;
   - SE-0104 - Protocol-oriented integers
   <https://github.com/apple/swift-evolution/blob/master/proposals/0104-improved-integers.md&gt;
   - SE-0107 - UnsafeRawPointer API
   <https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md&gt;
   - SE-0110 - Distinguish between single-tuple and multiple-argument
   function types
   <https://github.com/apple/swift-evolution/blob/master/proposals/0110-distingish-single-tuple-arg.md&gt;
   - SE-0111 - Remove type system significance of function argument
   labels
   <https://github.com/apple/swift-evolution/blob/master/proposals/0111-remove-arg-label-type-significance.md&gt;
   - SE-0120 - Revise partition Method Signature
   <https://github.com/apple/swift-evolution/blob/master/proposals/0120-revise-partition-method.md&gt;
   - SE-0127 - Cleaning up stdlib Pointer and Buffer Routines
   <https://github.com/apple/swift-evolution/blob/master/proposals/0127-cleaning-up-stdlib-ptr-buffer.md&gt;

These are all changes the community has approved for Swift but did not
make today's cutoff. Some of these proposals have implementations actively
underway. For those proposals already in active development — *and near
completion* — I am okay with extending the deadline for those changes
to *Friday, July 29*. Such changes need to be approved by the release
manager (myself) and should be merged into master via a pull request.
When creating the pull request, please assign it to me (tkremenek), and
mention the pull request on the swift-dev mailing list as well with the
SE number in the email title.

The rest of the unimplemented proposals do not make Swift 3. This leaves
us with the question of what to do with them. These proposals represent the
known and reviewed changes we want to make to Swift, but inevitably there
will *also* be changes that we don't even know about today that we will
want to take into Swift that can impact core source stability. That said,
we also have a very strong desire to maintain source compatibility with
Swift 3 and Swift 4 as much as possible to provide some stability for which
Swift users to build upon. The challenge of course is reconciling these
diametrically opposing goals: maintaining source stability while having the
ability to incorporate more core (and important) language changes that are
possibly source-breaking.

The Swift team at Apple has reflected on this and decided what it
"means" for Swift 3 to be source compatible with Swift 4 and later releases
going forward. Our goal is to allow app developers to combine a mix of
Swift modules (e.g., SwiftPM packages), where each module is known to
compile with a specific version of the language (module A works with Swift
3, module B works with Swift 3.1, etc.), then combine those modules into a
single binary. The key feature is that a module can be migrated from Swift
3 to 3.1 to 4 (and beyond) independently of its dependencies.

While the exact details of how we will accomplish this feat are still
being discussed, here is a sketch of how this will likely work in the Swift
4 timeframe. The key enabler is a new compiler flag that indicates the
language version to compile for (e.g., similar to the clang -std=c99 flag).
The compiler flag will be provided by the build system you are using (e.g.,
Xcode, SwiftPM, etc.) on a per-module basis:

   -

   For language syntax/semantics, the compiler can use the language
   mode to properly implement the language version being used by a module.
   -

   For the Standard Library, additive and subtractive changes are
   easily handled (the former by just adding them, the later by using
   deprecation techniques). For semantics changes, things are much more
   complicated, and will need further study.

The great thing about this approach is that a single Swift 4 compiler is
building all of the sources in an application. This allows us to roll out
this approach before achieving full ABI stability — something that will be
a goal for Swift 4, but is impractical to achieve for a Swift 3.x release.
It also provides us a general framework in the future for handling source
compatibility as Swift evolves.

To make this more concrete, suppose an application is written to use
Swift 4, but uses packages via SwiftPM that are written using Swift 3. A
single compiler would build both the app and the packages — thus ensuring
that all the compiled sources are binary compatible. It would not be the
case that a framework built with the Swift 3 compiler could be used by an
app built using the Swift 4 compiler. That kind of library binary stability
(ABI) will be a key goal of the Swift 4 release.

These constraints mentioned above will serve as scaffolding for Swift 4
development. Discussion about Swift 4 commences on Monday. Ahead of that,
Chris Lattner plans to send out thoughts from the Core team on some of the
known key goals (and non-goals) for the release. In the meantime, the focus
over the next couple days should be taking stock of what has landed for
Swift 3 and to see if any of the proposals mentioned above are close to
being completed or are truly out of scope.

Thank you again to everyone for making Swift 3 such as fantastic release!

Ted
_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub
Is SE-0077 going to be implemented for Swift 3?

It's been implemented.

https://github.com/apple/swift/blob/master/stdlib/internal/SwiftExperimental/SwiftExperimental.swift
Does this code actually run?

Well, it's just a bunch of declarations, but I suppose technically it "runs", yes. :)

If so, I will add "implemented" to the proposal, plus I still haven't added latest naming changes. ¯\_(ツ)_/¯

Please revise to match the implementation. It's slightly different beyond just the naming changes, as noted in the commit:

  Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub

John.

···

On Jul 28, 2016, at 4:15 AM, Anton Zhilin <antonyzhilin@gmail.com> wrote:

2016-07-28 1:17 GMT+03:00 Tony Allevato via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>>:
I noticed that while SE-0091 appears to be implemented (from a cursory glance at some of the affected types like Equatable and String), it looks like the named methods are still part of the FloatingPoint protocol and they still use global operators.

Is anyone tracking the migration of that protocol (and possibly also the new Integer protocols) to use the new operator technique? (I have to apologize for not being able to update the proposal with another PR that listed all those changes—my free time outside my day job has been significantly reduced lately.)

On Wed, Jul 27, 2016 at 12:38 PM Ted Kremenek via swift-evolution <swift-evolution@swift.org <mailto:swift-evolution@swift.org>> wrote:
Dear friends,

Today is July 27 — and the last planned day to take source-breaking changes for Swift 3. It has been an incredible ride to this point, so let's take stock of where we are. Here are the list of currently accepted — but not yet (fully) implemented — evolution proposals (this is drawn from the "accepted" but not marked "implemented" proposals from the swift-evolution <https://github.com/apple/swift-evolution&gt; repository):

SE-0025 - Scoped Access Level <https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md&gt;
SE-0042 - Flattening the function type of unapplied method references <https://github.com/apple/swift-evolution/blob/master/proposals/0042-flatten-method-types.md&gt;
SE-0045 - Add scan, prefix(while:), drop(while:), and iterate to the stdlib <https://github.com/apple/swift-evolution/blob/master/proposals/0045-scan-takewhile-dropwhile.md&gt;
SE-0068 - Expanding Swift Self to class members and value types <https://github.com/apple/swift-evolution/blob/master/proposals/0068-universal-self.md&gt;
SE-0075 - Adding a Build Configuration Import Test <https://github.com/apple/swift-evolution/blob/master/proposals/0075-import-test.md&gt;
SE-0077 - Improved operator declarations <https://github.com/apple/swift-evolution/blob/master/proposals/0077-operator-precedence.md&gt;
SE-0080 - Failable Numeric Conversion Initializers <https://github.com/apple/swift-evolution/blob/master/proposals/0080-failable-numeric-initializers.md&gt;
SE-0081 - Move where clause to end of declaration <https://github.com/apple/swift-evolution/blob/master/proposals/0081-move-where-expression.md&gt;
SE-0082 - Package Manager Editable Packages <https://github.com/apple/swift-evolution/blob/master/proposals/0082-swiftpm-package-edit.md&gt;
SE-0088 - Modernize libdispatch for Swift 3 naming conventions <https://github.com/apple/swift-evolution/blob/master/proposals/0088-libdispatch-for-swift3.md&gt;
SE-0089 - Renaming String.init<T>(_: T) <https://github.com/apple/swift-evolution/blob/master/proposals/0089-rename-string-reflection-init.md&gt;
SE-0092 - Typealiases in protocols and protocol extensions <https://github.com/apple/swift-evolution/blob/master/proposals/0092-typealiases-in-protocols.md&gt;
SE-0096 - Converting dynamicType from a property to an operator <https://github.com/apple/swift-evolution/blob/master/proposals/0096-dynamictype.md&gt;
SE-0099 - Restructuring Condition Clauses <https://github.com/apple/swift-evolution/blob/master/proposals/0099-conditionclauses.md&gt;
SE-0101 - Reconfiguring sizeof and related functions into a unified MemoryLayout struct <https://github.com/apple/swift-evolution/blob/master/proposals/0101-standardizing-sizeof-naming.md&gt;
SE-0102 - Remove @noreturn attribute and introduce an empty Never type <https://github.com/apple/swift-evolution/blob/master/proposals/0102-noreturn-bottom-type.md&gt;
SE-0103 - Make non-escaping closures the default <https://github.com/apple/swift-evolution/blob/master/proposals/0103-make-noescape-default.md&gt;
SE-0104 - Protocol-oriented integers <https://github.com/apple/swift-evolution/blob/master/proposals/0104-improved-integers.md&gt;
SE-0107 - UnsafeRawPointer API <https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md&gt;
SE-0110 - Distinguish between single-tuple and multiple-argument function types <https://github.com/apple/swift-evolution/blob/master/proposals/0110-distingish-single-tuple-arg.md&gt;
SE-0111 - Remove type system significance of function argument labels <https://github.com/apple/swift-evolution/blob/master/proposals/0111-remove-arg-label-type-significance.md&gt;
SE-0120 - Revise partition Method Signature <https://github.com/apple/swift-evolution/blob/master/proposals/0120-revise-partition-method.md&gt;
SE-0127 - Cleaning up stdlib Pointer and Buffer Routines <https://github.com/apple/swift-evolution/blob/master/proposals/0127-cleaning-up-stdlib-ptr-buffer.md&gt;
These are all changes the community has approved for Swift but did not make today's cutoff. Some of these proposals have implementations actively underway. For those proposals already in active development — and near completion — I am okay with extending the deadline for those changes to Friday, July 29. Such changes need to be approved by the release manager (myself) and should be merged into master via a pull request. When creating the pull request, please assign it to me (tkremenek), and mention the pull request on the swift-dev mailing list as well with the SE number in the email title.

The rest of the unimplemented proposals do not make Swift 3. This leaves us with the question of what to do with them. These proposals represent the known and reviewed changes we want to make to Swift, but inevitably there will also be changes that we don't even know about today that we will want to take into Swift that can impact core source stability. That said, we also have a very strong desire to maintain source compatibility with Swift 3 and Swift 4 as much as possible to provide some stability for which Swift users to build upon. The challenge of course is reconciling these diametrically opposing goals: maintaining source stability while having the ability to incorporate more core (and important) language changes that are possibly source-breaking.

The Swift team at Apple has reflected on this and decided what it "means" for Swift 3 to be source compatible with Swift 4 and later releases going forward. Our goal is to allow app developers to combine a mix of Swift modules (e.g., SwiftPM packages), where each module is known to compile with a specific version of the language (module A works with Swift 3, module B works with Swift 3.1, etc.), then combine those modules into a single binary. The key feature is that a module can be migrated from Swift 3 to 3.1 to 4 (and beyond) independently of its dependencies.

While the exact details of how we will accomplish this feat are still being discussed, here is a sketch of how this will likely work in the Swift 4 timeframe. The key enabler is a new compiler flag that indicates the language version to compile for (e.g., similar to the clang -std=c99 flag). The compiler flag will be provided by the build system you are using (e.g., Xcode, SwiftPM, etc.) on a per-module basis:

For language syntax/semantics, the compiler can use the language mode to properly implement the language version being used by a module.

For the Standard Library, additive and subtractive changes are easily handled (the former by just adding them, the later by using deprecation techniques). For semantics changes, things are much more complicated, and will need further study.

The great thing about this approach is that a single Swift 4 compiler is building all of the sources in an application. This allows us to roll out this approach before achieving full ABI stability — something that will be a goal for Swift 4, but is impractical to achieve for a Swift 3.x release. It also provides us a general framework in the future for handling source compatibility as Swift evolves.

To make this more concrete, suppose an application is written to use Swift 4, but uses packages via SwiftPM that are written using Swift 3. A single compiler would build both the app and the packages — thus ensuring that all the compiled sources are binary compatible. It would not be the case that a framework built with the Swift 3 compiler could be used by an app built using the Swift 4 compiler. That kind of library binary stability (ABI) will be a key goal of the Swift 4 release.

These constraints mentioned above will serve as scaffolding for Swift 4 development. Discussion about Swift 4 commences on Monday. Ahead of that, Chris Lattner plans to send out thoughts from the Core team on some of the known key goals (and non-goals) for the release. In the meantime, the focus over the next couple days should be taking stock of what has landed for Swift 3 and to see if any of the proposals mentioned above are close to being completed or are truly out of scope.

Thank you again to everyone for making Swift 3 such as fantastic release!

Ted

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org <mailto:swift-evolution@swift.org>
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org <mailto:swift-evolution@swift.org>
https://lists.swift.org/mailman/listinfo/swift-evolution

See the thread about stabilizing CI. The locked master while they worked
out issues with the CI systems. Last I read it should be unlocked soon.

···

On Thu, Jul 28, 2016 at 8:30 AM Brian Gesiak via swift-evolution < swift-evolution@swift.org> wrote:

Apologies if this was announced elsewhere: is commit access to master
restricted?

I noticed I couldn't merge some documentation improvements in
[SourceKit] Add documentation for SourceKit request types by RLovelett · Pull Request #3815 · apple/swift · GitHub, and just wanted to make sure
this was due to Swift 3 finalization.

If commit access is restricted, is it safe to assume that restriction will
be lifted on or around July 29?

- Brian Gesiak

On Thu, Jul 28, 2016 at 7:15 AM, Anton Zhilin via swift-evolution < > swift-evolution@swift.org> wrote:

Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub
Is SE-0077 going to be implemented for Swift 3?

https://github.com/apple/swift/blob/master/stdlib/internal/SwiftExperimental/SwiftExperimental.swift
Does this code actually run?

If so, I will add "implemented" to the proposal, plus I still haven't
added latest naming changes. ¯\_(ツ)_/¯

2016-07-28 1:17 GMT+03:00 Tony Allevato via swift-evolution <
swift-evolution@swift.org>:

I noticed that while SE-0091 appears to be implemented (from a cursory
glance at some of the affected types like Equatable and String), it looks
like the named methods are still part of the FloatingPoint protocol and
they still use global operators.

Is anyone tracking the migration of that protocol (and possibly also the
new Integer protocols) to use the new operator technique? (I have to
apologize for not being able to update the proposal with another PR that
listed all those changes—my free time outside my day job has been
significantly reduced lately.)

On Wed, Jul 27, 2016 at 12:38 PM Ted Kremenek via swift-evolution < >>> swift-evolution@swift.org> wrote:

Dear friends,

Today is July 27 — and the last planned day to take source-breaking
changes for Swift 3. It has been an incredible ride to this point, so let's
take stock of where we are. Here are the list of currently accepted — but
not yet (fully) implemented — evolution proposals (this is drawn from the
"accepted" but not marked "implemented" proposals from the
swift-evolution <https://github.com/apple/swift-evolution&gt; repository):

   - SE-0025 - Scoped Access Level
   <https://github.com/apple/swift-evolution/blob/master/proposals/0025-scoped-access-level.md&gt;
   - SE-0042 - Flattening the function type of unapplied method
   references
   <https://github.com/apple/swift-evolution/blob/master/proposals/0042-flatten-method-types.md&gt;
   - SE-0045 - Add scan, prefix(while:), drop(while:), and iterate to
   the stdlib
   <https://github.com/apple/swift-evolution/blob/master/proposals/0045-scan-takewhile-dropwhile.md&gt;
   - SE-0068 - Expanding Swift Self to class members and value types
   <https://github.com/apple/swift-evolution/blob/master/proposals/0068-universal-self.md&gt;
   - SE-0075 - Adding a Build Configuration Import Test
   <https://github.com/apple/swift-evolution/blob/master/proposals/0075-import-test.md&gt;
   - SE-0077 - Improved operator declarations
   <https://github.com/apple/swift-evolution/blob/master/proposals/0077-operator-precedence.md&gt;
   - SE-0080 - Failable Numeric Conversion Initializers
   <https://github.com/apple/swift-evolution/blob/master/proposals/0080-failable-numeric-initializers.md&gt;
   - SE-0081 - Move where clause to end of declaration
   <https://github.com/apple/swift-evolution/blob/master/proposals/0081-move-where-expression.md&gt;
   - SE-0082 - Package Manager Editable Packages
   <https://github.com/apple/swift-evolution/blob/master/proposals/0082-swiftpm-package-edit.md&gt;
   - SE-0088 - Modernize libdispatch for Swift 3 naming conventions
   <https://github.com/apple/swift-evolution/blob/master/proposals/0088-libdispatch-for-swift3.md&gt;
   - SE-0089 - Renaming String.init<T>(_: T)
   <https://github.com/apple/swift-evolution/blob/master/proposals/0089-rename-string-reflection-init.md&gt;
   - SE-0092 - Typealiases in protocols and protocol extensions
   <https://github.com/apple/swift-evolution/blob/master/proposals/0092-typealiases-in-protocols.md&gt;
   - SE-0096 - Converting dynamicType from a property to an operator
   <https://github.com/apple/swift-evolution/blob/master/proposals/0096-dynamictype.md&gt;
   - SE-0099 - Restructuring Condition Clauses
   <https://github.com/apple/swift-evolution/blob/master/proposals/0099-conditionclauses.md&gt;
   - SE-0101 - Reconfiguring sizeof and related functions into a
   unified MemoryLayout struct
   <https://github.com/apple/swift-evolution/blob/master/proposals/0101-standardizing-sizeof-naming.md&gt;
   - SE-0102 - Remove @noreturn attribute and introduce an empty Never
    type
   <https://github.com/apple/swift-evolution/blob/master/proposals/0102-noreturn-bottom-type.md&gt;
   - SE-0103 - Make non-escaping closures the default
   <https://github.com/apple/swift-evolution/blob/master/proposals/0103-make-noescape-default.md&gt;
   - SE-0104 - Protocol-oriented integers
   <https://github.com/apple/swift-evolution/blob/master/proposals/0104-improved-integers.md&gt;
   - SE-0107 - UnsafeRawPointer API
   <https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md&gt;
   - SE-0110 - Distinguish between single-tuple and multiple-argument
   function types
   <https://github.com/apple/swift-evolution/blob/master/proposals/0110-distingish-single-tuple-arg.md&gt;
   - SE-0111 - Remove type system significance of function argument
   labels
   <https://github.com/apple/swift-evolution/blob/master/proposals/0111-remove-arg-label-type-significance.md&gt;
   - SE-0120 - Revise partition Method Signature
   <https://github.com/apple/swift-evolution/blob/master/proposals/0120-revise-partition-method.md&gt;
   - SE-0127 - Cleaning up stdlib Pointer and Buffer Routines
   <https://github.com/apple/swift-evolution/blob/master/proposals/0127-cleaning-up-stdlib-ptr-buffer.md&gt;

These are all changes the community has approved for Swift but did not
make today's cutoff. Some of these proposals have implementations actively
underway. For those proposals already in active development — *and
near completion* — I am okay with extending the deadline for those
changes to *Friday, July 29*. Such changes need to be approved by the
release manager (myself) and should be merged into master via a pull
request. When creating the pull request, please assign it to me (
tkremenek), and mention the pull request on the swift-dev mailing list
as well with the SE number in the email title.

The rest of the unimplemented proposals do not make Swift 3. This
leaves us with the question of what to do with them. These proposals
represent the known and reviewed changes we want to make to Swift, but
inevitably there will *also* be changes that we don't even know about
today that we will want to take into Swift that can impact core source
stability. That said, we also have a very strong desire to maintain source
compatibility with Swift 3 and Swift 4 as much as possible to provide some
stability for which Swift users to build upon. The challenge of course is
reconciling these diametrically opposing goals: maintaining source
stability while having the ability to incorporate more core (and important)
language changes that are possibly source-breaking.

The Swift team at Apple has reflected on this and decided what it
"means" for Swift 3 to be source compatible with Swift 4 and later releases
going forward. Our goal is to allow app developers to combine a mix of
Swift modules (e.g., SwiftPM packages), where each module is known to
compile with a specific version of the language (module A works with Swift
3, module B works with Swift 3.1, etc.), then combine those modules into a
single binary. The key feature is that a module can be migrated from Swift
3 to 3.1 to 4 (and beyond) independently of its dependencies.

While the exact details of how we will accomplish this feat are still
being discussed, here is a sketch of how this will likely work in the Swift
4 timeframe. The key enabler is a new compiler flag that indicates the
language version to compile for (e.g., similar to the clang -std=c99 flag).
The compiler flag will be provided by the build system you are using (e.g.,
Xcode, SwiftPM, etc.) on a per-module basis:

   -

   For language syntax/semantics, the compiler can use the language
   mode to properly implement the language version being used by a module.
   -

   For the Standard Library, additive and subtractive changes are
   easily handled (the former by just adding them, the later by using
   deprecation techniques). For semantics changes, things are much more
   complicated, and will need further study.

The great thing about this approach is that a single Swift 4 compiler
is building all of the sources in an application. This allows us to roll
out this approach before achieving full ABI stability — something that will
be a goal for Swift 4, but is impractical to achieve for a Swift 3.x
release. It also provides us a general framework in the future for handling
source compatibility as Swift evolves.

To make this more concrete, suppose an application is written to use
Swift 4, but uses packages via SwiftPM that are written using Swift 3. A
single compiler would build both the app and the packages — thus ensuring
that all the compiled sources are binary compatible. It would not be the
case that a framework built with the Swift 3 compiler could be used by an
app built using the Swift 4 compiler. That kind of library binary stability
(ABI) will be a key goal of the Swift 4 release.

These constraints mentioned above will serve as scaffolding for Swift 4
development. Discussion about Swift 4 commences on Monday. Ahead of that,
Chris Lattner plans to send out thoughts from the Core team on some of the
known key goals (and non-goals) for the release. In the meantime, the focus
over the next couple days should be taking stock of what has landed for
Swift 3 and to see if any of the proposals mentioned above are close to
being completed or are truly out of scope.

Thank you again to everyone for making Swift 3 such as fantastic
release!

Ted
_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

_______________________________________________
swift-evolution mailing list
swift-evolution@swift.org
https://lists.swift.org/mailman/listinfo/swift-evolution

Fantastic! Here is the PR: Update SE-0077 to match the rationale by Anton3 · Pull Request #476 · apple/swift-evolution · GitHub
Two notes:

I had to introduce a FunctionArrowPrecedence to capture the parsing of ->

in expression contexts.

It looks like an implementation detail, so I didn't add it.

I found it convenient to continue to model the assignment property

explicitly.

I would prefer to stick to the original version. Changed to explicit
version anyway.

···

2016-07-29 0:33 GMT+03:00 John McCall <rjmccall@apple.com>:

On Jul 28, 2016, at 4:15 AM, Anton Zhilin <antonyzhilin@gmail.com> wrote:

Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub
Is SE-0077 going to be implemented for Swift 3?

It's been implemented.

https://github.com/apple/swift/blob/master/stdlib/internal/SwiftExperimental/SwiftExperimental.swift
Does this code actually run?

Well, it's just a bunch of declarations, but I suppose technically it
"runs", yes. :)

If so, I will add "implemented" to the proposal, plus I still haven't
added latest naming changes. ¯\_(ツ)_/¯

Please revise to match the implementation. It's slightly different beyond
just the naming changes, as noted in the commit:

Implement SE-0077: precedence group declarations. · apple/swift@c8c41b3 · GitHub

John