AsyncChannel makes one producer wait at send(). But hundreds of concurrent producers can still leave hundreds of suspended sends holding values. Backpressure is not a task limit. https://ivantokar.com/posts/swift-async-algorithms-backpressure-at-the-handoff

#SwiftLang

`if let name` creates a new, non-optional constant inside the `if`. Outside, the original `name` is still optional. Same name, different scope.

https://ivantokar.com/posts/optional-binding-turn-an-optional-into-a-value

#SwiftLang #MoS

SwiftPM pitch: put size/speed and cross-module optimization settings in Package.swift. Useful for special cases, but who gets the final say: a library or the app that builds it?

https://forums.swift.org/t/pitch-swiftpm-optimization-settings/90060

#SwiftLang

SwiftPM pitch: build-tool plugins could produce binaries, call CMake/Ninja, and handle external targets. The example builds SDL and an Android APK. Still a proposal, not shipped.

https://forums.swift.org/t/pitch-extending-build-tool-plugins-for-customizing-targets/90061

#SwiftLang

SE-0557 is under review: Hasher could accept RawSpan bytes directly, without an UnsafeRawBufferPointer. Reviewers are also asking about uninitialized bytes. Review ends Oct 20.

https://forums.swift.org/t/se-0557-add-rawspan-primitive-to-hasher/90025

#SwiftLang

SE-0556 is under review until Oct 23. It proposes Cell, ConstCell and Volatile for memory shared with C++, other processes or hardware. Useful safety tools, but Volatile is not a lock or an atomic..

https://forums.swift.org/t/se-0556-cell-constcell-and-volatile/89988

#SwiftLang

Swift 6.4.1 is out. It fixes an optimizer miscompile involving pointer-based writes, plus SwiftPM resolution and Swift Testing issues. Official patch release notes:

https://forums.swift.org/t/announcing-swift-6-4-1/90029

#SwiftLang

Hmmm... did #SwiftLang or #macOS URL(filePath:) change?

A program that used this code

let someURL = URL(filePath: “~foo/bar/”)

used to give the a url “file://Users/foo/bar/“. Now it given me a url to my home folder. It looks like “~foo” is being treated as “~”.

I'm sure this worked. A binary […]

Nice call out to ElementaryUI at sindresorhus.com/blog/swift-w... (@sindresorhus.com) @elementary.codes showing some great use of #swiftlang

SwiftPM accepted SE-0545: build traces to see where time goes, and task backtraces to explain unexpected rebuilds. Accepted, not in stable Swift yet.

#SwiftLang

https://forums.swift.org/t/accepted-se-0545-swiftpm-build-performance-debugging-options/89948

Removing a semicolon isn't always a text replacement. swift-format changes the syntax tree, keeps comments attached to the right statement, and handles the special do/while separator.

https://ivantokar.com/posts/swift-format-from-syntax-trees-to-readable-code

#SwiftLang

AsyncChannel makes Swift producers wait for demand. The interesting part is its state machine: handoff, cancellation races, and finish() semantics.

https://ivantokar.com/posts/swift-async-algorithms-backpressure-at-the-handoff

#SwiftLang

In Swift, if let checks whether a value exists. It does not check whether the value is useful. 0 and "" both pass optional binding. If an empty string is invalid for your feature, add that rule yourself.

#SwiftLang #MoS

https://ivantokar.com/posts/optional-binding-turn-an-optional-into-a-value

10 Swift OSS reviews: service lifecycles, jobs, HTTP types, snapshots, dependencies, GRDB, Deque, Nuke, Argument Parser, and swift-format. Each looks at one decision in the source.

All 10: https://ivantokar.com/series/daily-almost-swift-open-source-overview/

#SwiftLang #OpenSource

Swift 6.4 bug report: a `TaskGroup` child returning `(i, result)` from both `do` and `catch` gives `[0,0,0,0]` with `-O`, but `[0,1,2,3]` with `-Onone`. Open issue; narrow trigger.

https://github.com/swiftlang/swift/issues/93118

#SwiftLang

Swift compiler bug report: synthesized enum `hashValue` crashes on x86_64 Linux for a `(UInt128, UInt8)` payload. Reproduced with Swift 6.3.3 and 6.4 at `-Onone`; a misaligned `movaps` load is reported.

https://github.com/swiftlang/swift/issues/93129

#SwiftLang

#SwiftLang: Swift proposal: expose Unicode `Bidi_Class` as `scalar.properties.bidiClass`. Useful for text formatters handling mixed Arabic/Hebrew and LTR text. Awaiting review.

https://github.com/swiftlang/swift-evolution/pull/3523

swift-format works with Swift syntax trees, not just whitespace. I explored its parser, formatting rules, and pretty printer. #SwiftLang #OpenSource

https://ivantokar.com/posts/swift-format-from-syntax-trees-to-readable-code

7 Swift Evolution proposals changed status this week.

The tracker checks the official metadata daily and keeps a readable history, so you don't have to monitor every proposal manually.

swiftlee-weekly.com/swift-evolut...

#swiftlang #iosdev

Gave my first and only conference talk this year at #swiftCon in Berlin.
Honestly, didn't expect such a huge turnout and Q&A engagement for a fairly obscure and code-heavy topic. I feel incredibly grateful and energised! Happy to see European #swiftlang community going as strong as ever💪