波報 #17 - SwiftUI 聽說你很勇喔

Swift 大小事 2022/9/26 - 2022/10/2

Oct 02, 2022

💬 Pofat 的話

上週延期至本週一併出刊，很多人誤以為我和 13 一起打電動才沒寫週報，真相是我們兩個都忙炸，已經很久沒連線了！讀者們如果有推薦的連線遊戲歡迎介紹給我們。前前兩週剛好沒什麼大事，倒是上週跑出不少新內容，新的 HIG，早期泛型提案以及 NSSpain X 的議程影片，挑些喜歡的內容在家躲秋老虎吧！

《看前一期 | 所有文章》

🌎 On Swift Community

新 HIG 上線

Charing Data

https://developer.apple.com/design/human-interface-guidelines/patterns/charting-data

Halden Lin @halden_lin

Human Interface Guidelines for Charts are here! We've been working on these pages for a bit—hope you find them useful 📊🥳 Patterns page: developer.apple.com/design/human-i… Components page: developer.apple.com/design/human-i…

The top of the "Charting data" patterns page. Headline is: "Presenting data in a chart can help you communicate information with clarity and appeal."

The top of the "Charts" components page. The headline is "A chart helps you communicate data in a graphical, approachable way."

A screenshot of the "Best Practices" section of the "Charting data" page. There's a list of guidelines, the first being: "Use a chart when you want to highlight important information about a dataset."

A screenshot of the "Anatomy" section of the "Charts" components page. It's headlined by a graphic that points out the various parts of an anonymous bar chart, including marks, axes, grid lines, plot area, and more.

Live Activities
https://developer.apple.com/design/human-interface-guidelines/components/system-experiences/live-activities

Linda Dong 🍄 @lindadong

Design guidance for Live Activities on the Dynamic Island just dropped in the HIG 👀 developer.apple.com/design/human-i…

Screenshot of the home page for Live Activities in Apple’s Human Interface Guidelines

NSSpain X 影片上線

議程影片全部上線，我個人第一眼有興趣的是：

Composable Architecture at Scale
Lessons learnt rewriting SoundCloud in SwiftUI （好笑到哭了，但還沒看完下期週報再來分享心得）
Lessons from Mobile Networking at Scale
SwiftUI Navigation & URL Routing

NSSpain X @NSSpain

“Composable Architecture at Scale” by @merowing_ #nsspainX

vimeo.com1 - Composable Architecture at Scale - Krzysztof ZablockiDo you use TCA (The Composable Architecture)? Do you deal with performance and ergonomics issues? Then this is a much watch for you! NSSPAIN X Recorded & Produced…

SwiftUI 在 iOS 16 僅用 60Hz 的速度繪圖

看來是個 bug 且目前沒有 work around，在 iPad Pro 上能達到 120 Hz

Christian Selig @ChristianSelig

Now I’m even more confused. Here’s a slo-mo video showing the big difference in smoothness of UIKit (left) versus SwiftUI (right) animations on an iPhone 13 Pro. Choppy, right? But also, if the screen’s refresh rate is at 120 Hz (because of UIKit) why isn’t SwiftUI using it too?

iOS 上 SwiftUI 最高只以 60Hz 的速度在繪製而已，而 UIKit 在 iOS 15.4 就能達到

Christian Selig @ChristianSelig

Just tested, still no 120 Hz ProMotion with SwiftUI on iOS 16 😔

Christian Selig @ChristianSelig

One question with SwiftUI: how do you get it to work with ProMotion/120 Hz? Apple seemingly fixed UIKit in iOS 15.4, but if I try the same project in SwiftUI it only animates at 60 Hz. Am I doing something silly? (This is with the plist key entry) https://t.co/CIHyn8EOcP https://t.co/g17zybMDIr

純 SwiftUI 打造的 3D 物件動畫 Library

這個開發者之前才用 ShazamKit 做出彈琴時會自動翻譜的 app，這次則是做出像遊戲引擎裡會看到的 3D 動畫套件。

Andrew Zheng @aheze0

Introducing Prism, a library for animating 3D shapes. Made with 100% SwiftUI: github.com/aheze/Prism

SwiftUI Style 的 UIKit 語法

老實說現在寫回宣告式與命令式混合的語法滿痛苦，不過依 iOS 16 的混亂現況來看，在 SwiftUI 的黑箱中眷戀純粹語法的甜美也是種傷痛🥲

Steve Troughton-Smith @stroughtonsmith

Playing with Swift Result Builders to make SwiftUI-style UIKit layout. No autolayout, no Interface Builder (and no SwiftUI). So much of what’s good about SwiftUI could have been done without the magic, the unreliability, or the upheaval

This week I Learned

Swift 迭代小技巧

Kyle 🏳️‍🌈 @kyleve

One of my favorite Swift lessons over the last few months has been finding out about `sequence(first:next:)`, so you can easily iterate over a relationship like a superview: ``` for view in sequence(first: self, next: \.superview) { … } ```

AirPods Pro 2 盒子充電時可以開啟提示音，讚

Konrad ‘ktoso’ Malawski 🐟🏴‍☠️🇺🇦 @ktosopl

That’s pretty cute 😊

COBOL 有多勇？可能也是打造時的背景硬體能力非常有限，需要格外謹慎

Ariadne Conill @ariadneconill

a reminder that COBOL has been memory safe since 1959, as far as language design goes, it even goes farther than rust, outright banning things like recursion https://t.co/qQyphPGkSg

Value types 、或者說 copy-on-write 可以拯救你的人生

Alex Wenzel @alextwenzel

I've located the source of at least 49% of my suffering.

🗣️ On Swift Forum

SE-0373: Lift all limitations on variables in result builders (Reviewing)

目前的 result builder 只能用最常見的方式來宣告 local variable：一次一個，一定要有個儲存變數的空間及初始化的的表達式（代表不接受 computed 或 lazy variable），這 SE 將解開這些限制，還允許 property wrapper 的語法。

最後這點我認為是最有潛力的改進，但可能會引入令人困惑的操作空間，比如在裡面放入 @State 會是語法上允許卻沒有作用的。

Parameter Pack (Pitch)

社群期待已久的 variadic generic 終於有了更新，以新名稱和更具體的定義出發，分別為宣告型別的 Type parameter packs （以 <> 包起來的部分）與使用的 Value parameter packs，其中 ... 都表示「零或多個」的用法，比如：

Type 的部分可以擴充，比如 typealias G<E...> = (Array<E>...) 這樣的宣告中，G<Int, String> == (Array<Int>, Array<String>)；同時也可以加上型別的限制：

Value 的用法則同理，但多個種類時在 function 的參數一定要用外部的 label 來區隔，不能使用 _

還能透過傳給其它 function 來擴充，或者直接 iteration 所有值

這仍是早期提案，目前還有許多開放問題探討中，既然是新語法那當然大多的問題還是在語法本身，比如 pack 裡 ... 的使用和一般 parameter 的 ... 混用時看起來很 🤢

🎉 Swift Commits & Issues

[SE-0365] Allow implicit self for weak self captures

先前在 weak self closure 可以在 unwrap 後省去 self 的提案，看似單純背後卻發現了一個 type check 的 bug ，因為隱含的 self 是寫死在 non-optional，為了避免誤用要由 type checker 發出新的錯誤診斷說明，因此這個功能只能放到 Swift 6 上。