波報 #$16 - 只要起爭議，大聲就搞定

Swift 大小事 2022/9/12 - 2022/9/18

💬 Pofat 的話

本週社群很活躍，剛滿十年的知名 iOS/macOS conference NSSpain 辦了疫情後第一次實體活動，我的版面在 15 和 16 號兩天被完全洗版，今年由 Krzysztof 以 Composable Architecture at Scale 開場、 Brandon 講 URL Routing with NavigationStack 結尾， 光這兩場就很吸引人了，可惜這次無法參加，期待影片。

最大的新聞還是 Figma 以驚人的身價正式成為 Figma CC (Fm !?)，200 倍 revenue 的收購價真的盤，不愧是把設計師當盤子的大盤商。也許是因為 Figma 很成功地成為設計師和工程師間的橋樑，只在設計界的髒東西就這樣流入工程圈了，工程師們也是各種 RIP 。雖然怨聲載道但我認為這不全是壞事，我是不懂設計師的痛點、需求，不過目前的歷史紀錄告訴我們 Adobe 是眼光精準的收購家，Figma 吸金力道也不小，加入生態系也的確能再幫他們擴充客群、或把逃出 Adobe 魔掌的人們再捉回去🌚。

最後還有 print 與 debugger 哪個好的論戰，我還是總歸一句：

No code, no bug.

p.s. 寫稿時台灣正經歷許多地震，祝大家平安，也注意安全。

p.s+. 本週有事出門坐了十幾個小時的飛機，只能利用在機上的空檔撰寫週報，使用贊助款購買機上 Ｗi-Fi 才生得出這期，實乃讀者贊助播出啊！喜歡本週報的朋友請訂閱 Patreon 支持🙏

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🌎 On Swift Community

Dynamic Island 的已知情報

文件公佈、加上陸續有人收到新手機，因此大家把玩的成果展也不少，以下是我整理的消息和感想：

首先 Dynamic Island 是 ActivityKit 的一部分，它們皆利用了 WidgetKit 來打造UI：

Serenity Caldwell @settern

Oh hey! Updated ActivityKit documentation is out now, with more information about Dynamic Island. Have funnnn 🏝 developer.apple.com/documentation/…

developer.apple.comApple Developer Documentation

我們在 weak self 98 集也聊過 WidgetKit 下一個出席的大場合很可能是 AR 眼鏡，要讓 UI 上的物件要跟真實世界物件做良好的三維互動有太多挑戰，而 WidgetKit 的平面元件，要「貼」在現實的平面上相對容易許多。眼鏡會長時間戴著，也需要長時間呈現資訊變化的工具，即是 WidgetKit 的功能，Live Activity 也許是第一步，而 Dynamic Island 則是擔綱可愛角色。

只是文件裡的 API 看起來實在是有點糟，理解因多變化需把元件折成幾小塊來各自設定，但太多 trailing clousre 一層套一層實在難讀。如果上述預言成真，WidgetKitConfiguration 這不 scalable 的設計需要改變才行。（以上都我的空想也可能不會發生）

Majid Jabrayilov @mecid

My fasting app is the great candidate for the live activity widget. A few lines of code allows me to manipulate Dynamic Island.

討論度很高的動畫，其實是有著獨立的硬體支援，使其永保滑順以及更精細的細節以與實體的切孔結合。

Simeon @twolivesleft

Anyone know what Joz means when he mentions “Also an entirely new Display Engine in A16, this engine … enables the advanced anti-aliasing that makes Dynamic Island animations so incredibly smooth” Why would animations need additional hardware? SDF acceleration?

至於動畫很神奇的部分其實沒有什麼大祕密，完全不脫離動畫的 12 大原則，反而是有點復古化（一次結合許多原則的呈現，我個人感覺可能較容易分心），以下一些解釋：

Nate de Jager @dejager

Don't over think it. Dynamic Island blobs are drawn with basic geometry. No rasterization or image filters required.

Brad Ellis @BradEllis

Here's a better explanation of the image pipeline.

想知道動畫的 12 原則是什麼可以見這網頁，有影片輔助一看就能理解。

IOS 16 相簿實用新功能

功能開發者親自推薦，重複相片偵測真的讚！

Greg Heo @gregheo

The “more options” menu (aka meatball button) has some actions formerly in the share sheet as well as some new goodies.

Greg Heo @gregheo

OCR search from the Search tab now lets you find text that appears *within* your photos. Super useful to find receipts or documents or store signs or whatever 🔎

Greg Heo @gregheo

Was that a duplicate search result? Those two photos above look pretty similar. New duplicates detection to the rescue, under the Utilities section of the Albums tab!

Greg Heo @gregheo

Also note that the Hidden and Recently Deleted albums are locked. You can set this in the Photos section of the Settings app.

Greg Heo @gregheo

Bonus tip that @SamTheGeek reminded me of — multi-select and hit the (...) more options ellipsis to perform actions on multiple assets too!

行動網路的挑戰

JP Simard 上週在 NSSpain X 的議程，雖然還沒有影片但我找到 Lyft Engineer Blog 上的相關文章。由於行動網路的條件實在太變化多端，監測健康度更加困難，因此 Lyft 內部做了一套網路引擎（已開源）來取代 URLSession ，意外地 OOM 和 ANR 都下降了。

Marcin Krzyzanowski @krzyzanowskim

"surprised to see that switching from URLSession to an in-process networking engine actually decreased app hangs and OOM crashes" @simjp 😯 wait whaaaaat.

具體差在哪內文沒有很清楚的描述，有待影片或下篇文解釋，不過極度仰賴即時資訊的 App 開發者都應該要好好地思考這個問題 - 如何確認網路連線的健康度。

APP 效能分析實戰

我很喜歡看 emerge tools 的文，儘管我已經做了幾年的 performance engineer ，都還是能從他們的文中學到東西。Performance 這個領域的困難點在於你總是要在不熟悉的程式中回答原作者都回答不出來的問題：為什麼這段程式跑那麼慢？

現在的工具能給我們很多觀察的結果，可惜大多情況無法透過這些直接看到核心問題，如何在這些資訊海中找到合理的懷疑與見解，是這個工作的挑戰與有趣之處。

不過也是有例外：

Zoom's app actually spends 41ms sleeping on the main thread during startup.

哪個想靠這招升遷的工程師幹的？快出來自首吧！

SwiftOperator

SwiftOperators 是用來分析 operator 與其位置順序（precedence）的新 Swift Package ，加入成為 SwiftSyntax 的一部分

Doug Gregor @dgregor79

#SwiftLang allows user-defined operators with specified precedence and associativity. I've been working on a library to take a parsed Swift syntax tree and restructure it based on the operator-precedence rules:

github.comIntroduce a library to handle user-defined operators by DougGregor · Pull Request #619 · apple/swift-syntaxIntroduce a library that implements the semantics of Swift user-defined operators and precedence groups. The primary operation is a “fold”, which takes a sequence expression (i.e., something like a...

用途如下：

Doug Gregor @dgregor79

If you're parsing Swift code like "x + y * z" and you need to know that the * is computed first, i.e., that this is processed as "x + (y * z)", this is the library for you.

Print v.s. Debugger

最近的論戰焦點之一：你 debug 時都是用 print 還是 debugger 呢？

起於此兩文 （debugger 先的喔）

Sebastian Aaltonen @SebAaltonen

You like printf debugging? Introducing a tool called the Debugger. It automatically adds printf debug for every variable in your code base and collects that info into a nice UI. You can pause the execution, continue it and step one line at a time to see your execution flow.

Pierre Terdiman @PierreTerdiman

People publicly admitting that they never/rarely use a debugger are scary. Imagine if they would build cars / planes / etc the way you build your software: "oh I just look at it and reason about it in my head to find what's wrong with it." I wouldn't trust that code.

以及 print 也合用支持方（顯然 Xcode 是推手）

Slava Pestov @slava_pestov

I’ve been programming for more than 20 years and while I occasionally use debuggers for inspecting state after a crash, I rarely find single stepping or breakpoints helpful. Print statements (or even better, logging and tracepoints) for the win!

Sebastian Aaltonen @SebAaltonen

You like printf debugging? Introducing a tool called the Debugger. It automatically adds printf debug for every variable in your code base and collects that info into a nice UI. You can pause the execution, continue it and step one line at a time to see your execution flow.

Nick Lockwood @nicklockwood

I see the print vs debugger discourse is still raging 🙄 FWIW, I'm pretty sure the use (or not) of debuggers is almost always down to the reliability/UX of the tooling, not some preference or ignorance on the part of developers.

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🤪 Pofat 選推

Figma 我們懷念他（上香由此去）

詹致遠｜斜槓短期小說家 @fzhantw

幫 Figma 上香 ＼｜／

Apple ：小丑竟是我自己 🤡 （請依序閱讀下兩推）

Peter Steinberger @steipete

„There‘s a lot of wrappers, but don‘t worry, everything is generic.” #nsspainx Love this talk from Matias Villaverde and Rens Breur on SoundCloud’s SwiftUI rewrite

Peter Steinberger @steipete

“And then Apple emailed us that we’re 10 times slower than the competition - with a link to a guide how to implement UITableView - this was the highlight of my career.” #nsspainX

你看過 Cupertino 凌晨五點的樣子嗎？

Joe Groff @jckarter

If you wake up early enough in the morning in Cupertino, you might see the giant thumb that descends on Apple Park to do the Touch ID unlock

五花八門動態島

Kriss Smolka @ksmolka

Who has an iPhone 14 Pro right now? Need to test this on device asap! 🏝️ Hit The Island - our game concept for iPhone 14 Pro, still laggy but it’s turning out nice :) #iPhone14Pro #iOS16

Christian Selig @ChristianSelig

Okay y'all, I think I found the best idea for the Dynamic Island on the iPhone 14 Pro. I added a cat that lives up there like a tamagotchi and just hangs out and does cute stuff as you browse Reddit in my app (Apollo).

還在堅持中

Nate Bolt @boltron

New Sketch update timing is wild

有的沒的...

ᴺᴼᵀ Jony Ive @JonyIveParody

One More Thing… #Apple #iPhone

Joe Groff @jckarter

A new CPU architecture, designed from the ground up for accelerating Swift generics, called Existential RISC

Marin Todorov @icanzilb

Copying kanji on iOS16 looks truly magical 🪄🪄🪄

🔎Julia Evans🔍 @b0rk

debugging strategy: reread the error message