概要 TypeScriptは、JavaScriptに静的型付けの機能を加えたオープンソースのプログラミング言語です。本書では、根幹となるJavaScriptの仕様・機能とともに、TypeScript独自の仕様・機能を解説します。TypeScriptの基礎知識はこれ一冊だけで学べます。 静的型付き言語は世にいくつもありますが、TypeScriptの型システムは他に類を見ない高い表現力を持っています。本書の読者が、型の有効性を理解しTypeScriptらしいコードを書けるようになるために、本書では、プログラムの安全性を高める基本的な型の扱い方から、TypeScriptの「高い表現力」の源となっているリテラル型・ユニオン型・keyof 型の扱い方まで幅広く取り上げます。また、わかりにくい機能や型安全を脅かす危険な機能についてもごまかさず、歴史的経緯や目的・用途を踏まえたうえで最善の扱い方を説明し
Developers are increasingly relying on AI coding assistants to accelerate our daily workflows. These tools can autocomplete functions, suggest bug fixes, and even generate entire modules or MVPs. Yet, as many of us have learned, the quality of the AI’s output depends largely on the quality of the prompt you provide. In other words, prompt engineering has become an essential skill. A poorly phrased
Today we are excited to announce the availability of TypeScript 6.0! If you are not familiar with TypeScript, it’s a language that builds on JavaScript by adding syntax for types, which enables type-checking to catch errors, and provide rich editor tooling. You can learn more about TypeScript and how to get started on the TypeScript website. But if you’re already familiar with the language, you ca
よろしくお願いします！エンジニアのideです。 こちらはアドベントカレンダー23日目の記事になります！ 今年は体のあちこちに痛みを感じることが多かったので、来年こそは健康に過ごせる一年になるといいなと願っています。 さて、今回は今年やってきたことを振り返るのもいい機会だなと思い、特に触れる機会が多かったJavaScriptについてまとめてみることにしました。 結果的に基本的な内容が中心となりましたが、改めて理解を深める良いきっかけになったので、これはこれでよしとしています！ それではよろしくお願いいたします！ [目次] テンプレート文字列 スプレッド構文 分割代入 プロパティ名の短縮記法 オプショナルチェーン nullish(??)とfalsy(||)チェック ディープコピー アロー関数 Promise async/await forEachの中でasync/awaitが効かない おわりに
🌶️ IMHO 🌶️ - Rich Harris on frameworks, the web, and the edge.
この記事はSvelte/Sveltekitの作者であるRich Harris氏による講演「🌶️ IMHO 🌶️」を翻訳したものです。 この記事の作成には、Whisperによる書き起こし、DeepLおよびChatGPTによる翻訳を補助的に使用しています。 また、本文中には適宜訳注を入れています。 この場を借りて、翻訳を許可していただいたRich氏、 またこの翻訳をきめ細かくレビューしていただいたtomoam氏、英文解釈の相談に乗っていただいたshamokit氏へ感謝を表明したいと思います。 So, I'm going to be giving a talk tonight called In My Humble Opinion, and it's a collection of loosely connected thoughts about recent trends in front
The New Internet: Tailscale's Vision for the Future of Connectivity
Avery Pennarun is the CEO and co-founder of Tailscale. A version of this post was originally presented at a company all-hands. We don’t talk a lot in public about the big vision for Tailscale, why we’re really here. Usually I prefer to focus on what exists right now, and what we’re going to do in the next few months. The future can be distracting. But increasingly, I’ve found companies are startin
【KARAKURI LM 10本ノック】番外編： Chrome内蔵のローカルLLM (Gemini Nano)で「どこでもCopilot」を作ってみた
【KARAKURI LM 10本ノック】番外編： Chrome内蔵のローカルLLM (Gemini Nano)で「どこでもCopilot」を作ってみた 本記事中で紹介しているユーザスクリプト「どこでもCopilot」。ChromeビルトインのLLMで、任意のフォーム上で文章の続きをサジェスト。外部通信なし、無料で動作こんにちは、カラクリR&Dの吉田です。今回は、10本ノック「番外編」ということで、Google Chrome の最新版に先日（2024年8月22日）組み込まれたローカルLLMの話をします。 本記事の概要2024年8月22日に公開された Google Chrome の「バージョン128」にローカルLLM として Gemini Nano が組み込まれました。このLLMは、フロントエンド JavaScript から手軽に呼び出し可能で、ローカルLLMなので外部への通信は発生しません。
2025: The year in LLMs
31st December 2025 This is the third in my annual series reviewing everything that happened in the LLM space over the past 12 months. For previous years see Stuff we figured out about AI in 2023 and Things we learned about LLMs in 2024. It’s been a year filled with a lot of different trends. The year of “reasoning” The year of agents The year of coding agents and Claude Code The year of LLMs on th
JavaScriptの識別子
JavaScriptの識別子として使えるもの・使えないものに関して整理しました。 識別子、予約語、キーワード ECMAScriptでは識別子、予約語、キーワードを以下のように使っています 識別子 (identifier) とは、ざっくり言うとローカル変数名に使える名前のことです。が、この定義は細かいことを言うと状況によってぶれがあり複雑です。これを細かく見ていくのが本記事の主眼です。 例: foo 規格上は Identifier がこれに相当しますが、様々な例外を勘案するとこれをそのまま使うのが自然とは言えないため、以降では微妙に異なる定義を採用します。 予約語 (reserved word) とは、識別子と同じ形式であるにも関わらず識別子としては使えないもののことです。 例: if, public (strict modeの予約語だが、使い道はない) 非例: async (識別子として自
All JavaScript and TypeScript Features of the last 3 years
TypeScript as envisioned by Stable DiffusionThis article goes through almost all of the changes of the last 3 years (and some from earlier) in JavaScript / ECMAScript and TypeScript . Not all of the following features will be relevant to you or even practical, but they should instead serve to show what’s possible and to deepen your understanding of these languages. There are a lot of TypeScript fe
This blog post hopes to convince you that Python is a compiled language. And by “Python”, I don’t mean alternate versions of Python like PyPy, Mypyc, Numba, Cinder, or even Python-like programming languages like Cython, Codon, Mojo1—I mean the regular Python: CPython! The Python that is probably installed on your computer right now. The Python that you got when you searched “python” on Google and
Syntax Highlighting in Hand-Coded Websites The problem I have been trying to identify practical reasons why hand-coding websites with HTML and CSS is so hard (by hand-coding, I mean not relying on frameworks, generators or 3rd party scripts that modify the DOM). Let's say, I want to make a blog. What are the actual things that prevent me from making—and maintaining—it by hand? What would it take t
One of my favorite game jams is the legendary Js13kGames competition, where participants have one month to make a web browser game that fits in a 13 kilobyte zip file. To put that into perspective, a floppy disk from the before times could hold 1.44 MB, enough to fit over 100 JS13K games! In 2021 the contest celebrated its 10th annual event. The theme was “Space” and there were an impressive 223 g
In React Labs posts, we write about projects in active research and development. We’ve made significant progress on them since our last update, and we’d like to share what we learned. React Server Components React Server Components (or RSC) is a new application architecture designed by the React team. We’ve first shared our research on RSC in an introductory talk and an RFC. To recap them, we are
Today we are excited to announce the Release Candidate (RC) of TypeScript 6.0! To get started using the RC, you can get it through npm with the following command: npm install -D typescript@rc TypeScript 6.0 is a unique release in that we intend for it to be the last release based on the current JavaScript codebase. As announced last year (with recent updates here), we are working on a new codebase
In this tutorial, you'll learn how the React compiler can help you write more optimized React applications. React is a user interface library that has been doing its job quite well for over a decade. The component architecture, uni-directional data flow, and declarative nature stand out in helping devs building production-ready, scalable software applications. Over the releases (even up until the
When a single-page application needs to fetch data from a remote source, it needs to do so while remaining responsive and providing feedback to the user during an often slow query. Five patterns help with this. Asynchronous State Handler wraps these queries with meta-queries for the state of the query. Parallel Data Fetching minimizes wait time. Fallback Markup specifies fallback displays in marku
Blogged Answers: My Experience Modernizing Packages to ESM
Random musings on React, Redux, and more, by Redux maintainer Mark "acemarke" Erikson This is a post in the Blogged Answers series. Details on the painful experiences and hard-earned lessons I've learned migrating the Redux packages to ESM Table of Contents 🔗︎ Introduction Redux Packages Background Packages and Configurations Issue History Early Attempts Migrating to Vitest Initial Alpha Testing
11th March 2025 Online discussions about using Large Language Models to help write code inevitably produce comments from developers who’s experiences have been disappointing. They often ask what they’re doing wrong—how come some people are reporting such great results when their own experiments have proved lacking? Using LLMs to write code is difficult and unintuitive. It takes significant effort
Chapter 8: CSS | CSS-Tricks
In June of 2006, web developers and designers from around the world came to London for the second annual @media conference. The first had been a huge success, and @media 2006 had even more promise. Its speaker lineup was pulled from some of the most exciting and energetic voices in the web design and browser community. Chris Wilson was there to announce the first major release to Microsoft’s Inter
概要 2010年の刊行から約100,000部の実績を誇るロングセラーを、ECMAScript 2022に対応した内容で200ページ増の大幅改訂。最新の基本文法から、開発に欠かせない応用トピックまで解説します。JavaScriptらしく書くために大切なオブジェクトの扱い方や、大規模開発でさらに実用的になったオブジェクト指向構文を学び、しっかりと動くプログラムの作り方を本質から理解できます。 こんな方にオススメ JavaやC言語などほかのプログラミング言語の経験があり、JavaScriptを新規に学びたい方 JavaScriptを多少使えるけど基本が不安な方 ECMAScript 2022による新たなJavaScript記法を学びたい方 目次 Chapter 1 イントロダクション 1.1 JavaScriptとは？ 1.1.1 JavaScriptの歴史 1.1.2 復権のきっかけはAjax
The Junior Developer Extinction: We’re All Building the Next Programming Dark Age
“I have not failed. I’ve just found 10,000 ways that won’t work.” — Thomas Edison Though to be fair, Edison never had to explain to his manager why the AI-generated light bulb stopped working, and nobody on the team understood the filament design. Picture this scene, familiar to anyone who’s conducted code reviews in the past year: A junior developer presents their pull request with the quiet conf
If you are a Rubyist, you’ve likely been writing # frozen_string_literal: true at the top of most of your Ruby source code files, or at the very least, that you’ve seen it in some other projects. Based on informal discussions at conferences and online, it seems that what this magic comment really is about is not always well understood, so I figured it would be worth talking about why it’s there, w
We've talked quite a bit about linting in the past two posts of this series, so I thought it's time to give eslint the proper limelight it deserves. Overall eslint is so flexible, that you can even swap out the parser for a completely different one. That's not a rare scenario either as with the rise of JSX and TypeScript that is frequently done. Enriched by a healthy ecosystem of plugins and prese
Err... thanks for the technical explanation. But what does this actually mean in real life? Which setting should you use? Does it even matter? And if it does, why don't those clever browser engineers just set it to the best setting? Well recently I ranted on Twitter about this (as I am often want to do!) in a long thread that really should have been a blog post. So here is that blog post. Some mis
とほほのKotlin入門 - とほほのWWW入門
概要 Kotlinとは Kotlinを試してみる インストール Hello world 基本的な覚え事 コマンド引数 print, println コメント 行末のセミコロン コーディング規約 キーワード 変数 型 真偽値(Boolean) 数値(Byte, Short, Int, Long, Float, Double) 文字(Char) 文字列(String) Any型(Any) 型変換 配列 リスト セット マップ レンジ(range) 型を確認する(is, !is) 型の別名(typealias) キャスト(as, as?) ダイナミック型(dynamic) 演算子 制御構文 if式 fotループ forEachループ whileループ do-whileループ break文 continue文 when式 ラベル(@) 例外処理(try, throw, catch, finally
published 10/10/2023 Replacing WebRTC The long path to use something else for real-time media. tl;dr If you primarily use WebRTC for… real-time media: it will take a while to replace WebRTC; we’re working on it. data channels: WebTransport is amazing and actually works. peer-to-peer: you’re stuck with WebRTC for the forseeable future. Disclaimer I spent almost two years building/optimizing a parti
Update 1.60.1: The update addresses these issues. Update 1.60.2: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the August 2021 release of Visual Studio Code. There are many updates in this version that we hope you will like, some of the key highlights include: Automatic language detection - Programming l
ビルド不要！ Google Apps Script のウェブアプリを Vue.js と Tailwind CSS で実装しよう
この記事は ヌーラボブログリレー2025夏 の1日目として投稿しています。 明日以降の執筆予定については 夏の恒例！「ヌーラボブログリレー2025 夏」を開催します！ #ヌーラボブログリレー2025夏 をご覧ください！ はじめに Google Apps Script (GAS) は Google の各サービスと連携したアプリケーションを開発できるプラットフォームです。 GAS には doGet メソッドを定義することで、 UI を持つ Web アプリケーションを公開する機能があります。 この機能を使えば、サーバーサイドの GAS の関数を JavaScript から呼び出したり、動的な値を埋め込んだ HTML を生成したりすることが可能です。 しかし、 GAS には一つ大きな制約があります。 それは、 JavaScript や CSS といったクライアントサイドのアセットファイルを単体でホ
Exactly ten years ago today, we published "Why We Created Julia", introducing the Julia project to the world. At this point, we have moved well past the ambitious goals set out in the original blog post. Julia is now used by hundreds of thousands of people. It is taught at hundreds of universities and entire companies are being formed that build their software stacks on Julia. From personalized me
research!rsc: Programming Language Memory Models (Memory Models, Part 2)
Programming language memory models answer the question of what behaviors parallel programs can rely on to share memory between their threads. For example, consider this program in a C-like language, where both x and done start out zeroed. // Thread 1 // Thread 2 x = 1; while(done == 0) { /* loop */ } done = 1; print(x); The program attempts to send a message in x from thread 1 to thread 2, using d
Build strongly typed polymorphic components with React and TypeScript - LogRocket Blog
Real-world examples of polymorphic components There’s a nonzero chance you’ve already used a polymorphic component. Open source component libraries typically implement some sort of polymorphic component. Let’s consider some you may be familiar with: the Chakra UI as prop and MUI component prop. Chakra UI’s as prop How does Chakra UI implement polymorphic props? The answer is by exposing an as prop
What if you don't need MCP at all? 2025-11-02 One chonky MCP server Table of contents After months of agentic coding frenzy, Twitter is still ablaze with discussions about MCP servers. I previously did some very light benchmarking to see if Bash tools or MCP servers are better suited for a specific task. The TL;DR: both can be efficient if you take care. Unfortunately, many of the most popular MCP
Technology Trends for 2024
This has been a strange year. While we like to talk about how fast technology moves, internet time, and all that, in reality the last major new idea in software architecture was microservices, which dates to roughly 2015. Before that, cloud computing itself took off in roughly 2010 (AWS was founded in 2006); and Agile goes back to 2000 (the Agile Manifesto dates back to 2001, Extreme Programming t
Face reveal 2020. This post has some art in it, which you absolutely need to click through and go watch, because it’s meant to be seen in motion, and is pretty amazing. All images in this post are courtesy Alexis Andre. Subscribe now The technical side of making artThere is a stereotype of artists as strictly right-brained personalities. (Insert your favorite pop-culture image of a painter in a be
Update 1.79.1: The update addresses this security issue. Update 1.79.2: The update addresses these issues. Downloads: Windows: x64 Arm64 | Mac: Universal Intel silicon | Linux: deb rpm tarball Arm snap Welcome to the May 2023 release of Visual Studio Code. There are many updates in this version that we hope you'll like, some of the key highlights include: Read-only mode - Mark specific files and f
What's new in Swift 5.5? Async/await, actors, throwing properties, and more! Swift 5.5 comes with a massive set of improvements – async/await, actors, throwing properties, and many more. For the first time it’s probably easier to ask “what isn’t new in Swift 5.5” because so much is changing. In this article I’m going to walk through each of the changes with code samples, so you can see how each of
There is a boundary around every black hole where the velocity required to escape its gravitational pull exceeds the speed of light. Once anything, including light itself, passes over that threshold, it is trapped inside the mysterious interior of the black hole forever. There is no escape, and there is no return back to the rest of the universe. This boundary is called the black hole’s event hori
Browser-Powered Desync Attacks: A New Frontier in HTTP Request Smuggling
This request triggered an extremely suspicious intermittent 400 Bad Request response from various websites that were running AWS Application Load Balancer (ALB) as their front-end. Investigation revealed that ALB was mysteriously adding a 'Transfer-Encoding: chunked' header while downgrading the request to HTTP/1.1 for forwarding to the back-end, without making any alterations to the message body:
AWS Amplify Hosting でサーバーサイドレンダリングのための IAM Compute Roles | Amazon Web Services
Amazon Web Services ブログ AWS Amplify Hosting でサーバーサイドレンダリングのための IAM Compute Roles 今日、AWS Amplify Hosting は、AWS Amplify アプリケーションの IAM Compute Roles を導入しました。これにより、コンピュート実行時から AWS サービスへの安全なアクセスを可能にし、サーバーサイドレンダリング機能を拡張できるようになりました。IAM Compute Roles を使えば、開発者はサーバーサイドレンダリングアプリに特定の権限を付与でき、Amplify が他の AWS サービスへの承認された呼び出しを行えるようになります。この新機能により、セキュリティのベストプラクティスを維持しながら、開発プロセスを加速できます。 主な機能 IAM Compute Roles を使えば、以
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プロを目指す人のためのTypeScript入門 安全なコードの書き方から高度な型の使い方まで | 技術評論社
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