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Cheng Lou, a former React Core team member and engineer at Midjourney says he "crawled through depths of hell" to bring us Pretext – a fast, accurate, and comprehensive text measurement library that could change UI design forever. Let's run it.

#coding #programming #typescript #javascript

🔖 Topics Covered
- Who is Cheng Lou?
- Intro to Pretext
- What makes dynamic text rendering so hard?
- Pretext demo

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Fireship is a YouTube channel created by Jeff Delaney that offers quick tutorials and explanations on web development, programming, and tech trends. Known for the “100 Seconds of Code” and “The Code Report” series, the channel breaks down complex topics in a short, engaging format, covering everything from JavaScript frameworks to emerging technologies.

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Pretext is a new TypeScript library by Changlu (former React core team member) that bypasses browser layout reflow for text measurement. It uses the Canvas API to measure text width without touching the DOM, and a custom algorithm for calculating line breaks and text height across browsers and languages. This enables building performant text-heavy UIs like virtualized lists and masonry layouts without the typical performance cost of triggering browser reflows.

He just crawled through hell to fix the browser…

<p>This has its uses, but is so overhyped. “fixed the browser”, “solved the web”, bollocks. Most of the demos while impressive and artistic, are completely useless. Text heavy pages that reorder their paragraphs 120 times per second is cool, but impractical for actual reading and the AI that’s gonna summarize your blog post is not gonna care for your fancy animation anyway. I guess this gives the people hosting ads a way to make their sites even more obnoxious because now we can have a static ad in the middle of the page while the article is flowing around it.</p>
