🦊 Kotlin @ JetBrains. 日本語OK。Play the guitar (a bit). Interested in Zen. Inspired by music. Welcome.
Japan
Joined April 2009
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Yan retweeted
✨Kotlin Fest 2026 招待講演紹介 ✨
昨年に引き続き、JetBrains からジュラノフ ヤン さん（@yanewm）にご登壇いただきます！
「Tales from Kotlin」
Kotlinの新機能は、ある日突然できあがるわけではありません。
チケット発売中！
2026.kotlinfest.dev/ticket
#KotlinFest
And then spend 3 million instructions to show it to the user 10 layers above in a Chrome wrapper?
CPU3命令でうるう年を判定する最適化。
bool is_leap_year_fast(uint32_t y) {
return ((y * 1073750999) & 3221352463) <= 126976;
}
A leap year check in three instructions
hueffner.de/falk/blog/a-leap…
GCCの実装でも取り入れられた。
github.com/gcc-mirror/gcc/co…
That’s one of the reasons why I chose AppKit over SwiftUI for Marta.
I compared UIKit and SwiftUI performance with the most ridiculous scroll view possible.
Memory usage wasn’t dramatic, but was interestingly spiky. Perhaps due to the different numbers of gifs and different resolution of the images rendered on each cell.
When it came to profiling peak memory and energy usage, I expected UIKit to yield the same kind of results I saw in SwiftUI: We’re still displaying an enormous number of elements, animating them the same, and these images are not any bigger or smaller, right?
Now don’t I look silly.
Memory usage hovered around 92MB for UIKit, compared to 248MB in SwiftUI.
Read my scientific performance comparison right here 🧪 blog.jacobstechtavern.com/p/…
Yan retweeted
KotlinFest2025閉会しました🔚
スポンサーやスピーカ皆様方、参加者の方など全ての方の協力があってここまで来れました！
またいつの日になるかわかりませんが会える機会を心待ちにしています！
本日は本当にありがとうございました！🎉🎉
Yan retweeted
今週土曜日（11月1日）はいよいよ Kotlin Fest 2025！
JetBrains Kotlin 開発チームの @yanewm さんによるセッションをお楽しみに🎉
まだ参加登録がお済みでない方は、ぜひお早めに！
【Kotlin Fest】豪華セッションの一部をご紹介 📢
お待たせしました！招待sessionのご案内です！
セッションタイトル: Kotlinを支える技術：言語設計と縁の下の力持ち
登壇者: ジュラノフ ヤンさん
チケット購入はコチラから👇
kotlinfest.dev/tickets #KotlinFest
SlimBlade Pro by Kensington is the worst thing I've ever bought in 2025 so far. Cheap plastic, gets dusty in hours (while everything else on the table doesn't), extremely crappy and bloated software for Mac (the kernel extension constantly consumes 10%+ CPU).
I've bought a home bakery – a simple offline device (Panasonic). It has a digital clock, though, so I can schedule baking.
I plug it in and see the clock being set up correctly. Out of the box! Right from the factory! How cool is that?
Experimenting with SwiftUI for Marta. In simpler cases, it's very convenient, but if you care at least a bit about how the result is rendered, all conveniences become enemies.
Yan retweeted
Open Source People are Fighting to Kill Open Source Projects
A large portion of the people in "Open Source" -- including Red Hat -- have been moving, rather dramatically, away from some of the core ideals of "Open Source".
Every time I program in Swift, I cry bloody tears because of how clumsy Xcode is. Everything is so dumb and impractical compared to IJ that I spend several times more time on even the simplest things. Do Apple’s own developers seriously not use it themselves?
With that in mind, I feel like Kotlin/Native’s real selling point isn’t even Multiplatform – it’s that you don’t have to deal with that broken IDE as much.
I’m not saying the Kotlin plugin in IJ is perfect. It isn't. But it’s just on a whole different level compared to Xcode.
