2026-03-30 04:08:45
Exciting new browser library from Cheng Lou, previously a React core developer and the original creator of the react-motion animation library.
Pretext solves the problem of calculating the height of a paragraph of line-wrapped text without touching the DOM. The usual way of doing this is to render the text and measure its dimensions, but this is extremely expensive. Pretext uses an array of clever tricks to make this much, much faster, which enables all sorts of new text rendering effects in browser applications.
Here's one demo that shows the kind of things this makes possible:
The key to how this works is the way it separates calculations into a call to a prepare() function followed by multiple calls to layout().
The prepare() function splits the input text into segments (effectively words, but it can take things like soft hyphens and non-latin character sequences and emoji into account as well) and measures those using an off-screen canvas, then caches the results. This is comparatively expensive but only runs once.
The layout() function can then emulate the word-wrapping logic in browsers to figure out how many wrapped lines the text will occupy at a specified width and measure the overall height.
I had Claude build me this interactive artifact to help me visually understand what's going on, based on a simplified version of Pretext itself.
The way this is tested is particularly impressive. The earlier tests rendered a full copy of the Great Gatsby in multiple browsers to confirm that the estimated measurements were correct against a large volume of text. This was later joined by the corpora/ folder using the same technique against lengthy public domain documents in Thai, Chinese, Korean, Japanese, Arabic, and more.
Cheng Lou says:
The engine’s tiny (few kbs), aware of browser quirks, supports all the languages you’ll need, including Korean mixed with RTL Arabic and platform-specific emojis
This was achieved through showing Claude Code and Codex the browsers ground truth, and have them measure & iterate against those at every significant container width, running over weeks
Via @_chenglou
Tags: browsers, css, javascript, testing, react, typescript
2026-03-30 02:46:16
Tool: Python Vulnerability Lookup
I learned that the OSV.dev open source vulnerability database has an open CORS JSON API, so I had Claude Code build this HTML tool for pasting in a pyproject.toml or requirements.txt file (or name of a GitHub repo containing those) and seeing a list of all reported vulnerabilities from that API.
Tags: tools, python, supply-chain, vibe-coding, security
2026-03-28 20:04:26
The thing about agentic coding is that agents grind problems into dust. Give an agent a problem and a while loop and - long term - it’ll solve that problem even if it means burning a trillion tokens and re-writing down to the silicon. [...]
But we want AI agents to solve coding problems quickly and in a way that is maintainable and adaptive and composable (benefiting from improvements elsewhere), and where every addition makes the whole stack better.
So at the bottom is really great libraries that encapsulate hard problems, with great interfaces that make the “right” way the easy way for developers building apps with them. Architecture!
While I’m vibing (I call it vibing now, not coding and not vibe coding) while I’m vibing, I am looking at lines of code less than ever before, and thinking about architecture more than ever before.
— Matt Webb, An appreciation for (technical) architecture
Tags: matt-webb, ai, llms, vibe-coding, coding-agents, ai-assisted-programming, generative-ai, agentic-engineering, definitions
2026-03-28 07:42:47
Release: datasette-showboat 0.1a2
I added an option to export a Markdown file from my app that lets Showboat incrementally publish updates to a remote server.
2026-03-28 05:11:17
FWIW, IANDBL, TINLA, etc., I don’t currently see any basis for concluding that chardet 7.0.0 is required to be released under the LGPL. AFAIK no one including Mark Pilgrim has identified persistence of copyrightable expressive material from earlier versions in 7.0.0 nor has anyone articulated some viable alternate theory of license violation. [...]
— Richard Fontana, LGPLv3 co-author, weighing in on the chardet relicensing situation
Tags: open-source, ai-ethics, llms, ai, generative-ai, ai-assisted-programming
