Top all-time · #3085
Pavel Panchekha
Personal blog · pavpanchekha.com/blog · on HN as pavpanchekhaprogrammingai
Pavel Panchekha's personal blog at pavpanchekha.com covers programming and ai. Since 2011, 25 different Hacker News readers have linked it 53 times, most often “Should CSS be a constraint system instead?”. It is still writing: the last post was on 2026-04-24, and you can follow it by feed.
Too few sampled comments (9) to say how often HN recommends it.?
Why HN links it
HN readers link Pavel Panchekha's posts on the floating-point repair tool Herbie, a ChatGPT-vs-Herbie comparison, CSS float formalisation, type derivatives and zippers. One commenter calls a post 'interesting' and another a write-up 'great'.
Summarised by Claude from a sample of 9 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Most-linked posts?
- Should CSS be a constraint system instead?3 people · 3 mentions · first linked 2025-12-04
- /blog/css-floats.html2 people · 4 mentions · first linked 2021-04-06
- Top-Down LR Parsing2 people · 2 mentions · first linked 2023-03-13
- Complex Square Roots in math.js2 people · 2 mentions · first linked 2014-09-16
- The Promise of P-Graphs2 people · 2 mentions · first linked 2025-11-25
- ChatGPT vs. Herbie2 people · 2 mentions · first linked 2023-06-18
What Hacker News says?
FWIW, Pavel, one of the authors, has devoted considerable time into what is one of the very, very few attempts at a formal specification for CSS (the static/float layout fragment cf [1]). It's a Racket program generating Z3 SMT solver code for verifying an instance layout (which also looks like Scheme) so it's not for the faint-hearted ;) but maybe just what an FP fan on HN is looking for as a challenge. [1]: https:…
Comment linking /blog/css-floats.html
on “Web Browser Engineering (2021)”Submitted We'd be better off with 9-bit bytes as a story · 188 points
HN discussionThis is an interesting post. An expert in numerical analysis compares the output of a tool which optimizes floating point expressions for speed and accuracy with the output generated by chatgpt on the same benchmarks: https://pavpanchekha.com/blog/chatgpt-herbie.html > I wouldn't use it—sanity-checking its algebra is a lot of work, but even if you fixed that up, the high-level ideas typically aren't that good either…
Comment linking /blog/chatgpt-herbie.html
on “Devin: AI Software Engineer”Submitted Treaps: A Simple Balanced Binary Tree as a story · 73 points
HN discussionYes, I actually have a kind-of related blog post: https://pavpanchekha.com/blog/proof-system-os.html I tried to restrict my post to just set theory because this philosophical point is often hard for people to grasp.
Comment linking /blog/proof-system-os.html
on “How many real numbers exist? New proof moves closer to an answer”Submitted Should CSS be a constraint system instead? as a story · 38 points
HN discussionNo. Django solves the 90% problem, which is usually a fine approach but will llikely lead to security vulnerabilities down the line. I'll refer to something I wrote last time I had this argument: http://pavpanchekha.com/programming/injection.html .
Comment linking /programming/injection.html
on “Break Google”Submitted Should CSS be constraints? as a story · 25 points
HN discussionThis talk was great, especially its focus on non-parametric techniques. A lot of people are mislead by the traditional statistics approach, where it looks like stats is about memorizing a relatively short list of (really scary) formulas that let you compute one or another thing. People do not think about how these formulas come about, and the simple ideas behind them. On the other hand, I think there is not enough w…
Comment linking /blog/stats1.html
on “Statistics for Hackers”Submitted (call/cc call/cc) and friends as a story · 15 points
HN discussionAuthor here. Unfortunately, a lot of this "conceptual" content doesn't really exist, just because there aren't that many people who work on web browsers, plus it takes a lot of work to get a comprehensive view. I wrote up this guide about CSS floats, for example: https://pavpanchekha.com/blog/css-floats.html It is just about complete, but it also took me about a year of work to get that understanding (from reading t…
Comment linking /blog/css-floats.html
on “How Browsers Lay Out Web Pages”Submitted Top-Down LR Parsing as a story · 10 points
HN discussionIf you're interested in Typed Racket, you might be interested in my experience: http://pavpanchekha.com/blog/typed-racket-1.html I'm a fairly experienced Racket developer (6 years) but it was my first time trying Typed Racket. I ended up not keeping the part of my code that I typed.
Comment linking /blog/typed-racket-1.html
on “Racket for E-Commerce”Submitted FastTwoSum Is Faster Than TwoSum as a story · 5 points
HN discussionThe payoff is in part 3, here, where crntaylor explains how to take the derivative(!) of a type: http://chris-taylor.github.io/blog/2013/02/13/the-algebra-of... You can find a somewhat more mathematical explanation here, with explanations of why this is useful: http://pavpanchekha.com/blog/zippers/derivative.html The most obvious use for derivative types is the automated creation of "zipper" types for functional dat…
Comment linking /blog/zippers/derivative.html
on “The Algebra of Algebraic Data Types”Submitted Pedestrian Statistics as a story · 5 points
HN discussionThere's actually a great write-up on how Herbie was used in the real-world to fix and improve math.js: https://pavpanchekha.com/blog/casio-mathjs.html I've personally used it for improving some distance-field approximation code on the GPU (made it easier to translate the math into numerically-stable code).
Comment linking /blog/casio-mathjs.html
on “Herbie: Automatically rewrites expressions to minimize floating point error”Submitted Should CSS Be Constraints? as a story · 4 points
HN discussionYou can take this idea further by trying to find computational analogues of more complex algebra structures and operations. For example, the derivative of a type function gives the type of ‘one-hole contexts’ of that type[0], which gives rise to the work on zippers for context-preserving transformation in functional data structures, things like Rust's `Entry` API for maps. Amr Sabry has been doing work on extending…
Comment linking /blog/zippers/derivative.html
on “Linear Algebra of Types (2019)”Submitted An Accurate Quadratic Formula as a story · 4 points
HN discussionI can't recall the last paper that I had to fluff up to fill all 10 or 12 pages; nor do I remember any colleagues doing anything like that. In truth, every paper halves in size between the first good draft and the submission. Writing a good paper can take a month, and involve writing dozens of drafts (I wrote a post about this at https://pavpanchekha.com/blog/paper-section-stats.html ). Now, you might say that the p…
Comment linking /blog/paper-section-stats.html
on “John Ioannidis has dedicated his life to quantifying how science is broken”Submitted The Promise of P-Graphs as a story · 3 points
HN discussion> The thing that I can't understand is, why did it take SO LONG to get useable, proper, and intuitive CSS-based layout on web-pages? Many reasons: - HTML and CSS are not designed for anything complex. HTML and CSS at their core are only meant to display a static page of text and some images in a single rendering pass on a computer from 1990s. - Many decisions in CSS (especially early CSS) are one-off solutions that…
Comment linking /blog/css-problems.html
on “CSS Container Queries in Web Components”Submitted Teaching parsing: From Top-down LL (recursive descent) to Top-down LR parsing as a story · 3 points
HN discussionI do something similar for http://pavpanchekha.com/ (I describe the approach here: http://pavpanchekha.com/blog/org-mode-publish.html ). I've found it a pretty good blogging platform so far. A huge plus is the diversity of markup (definition lists, tables, footnotes, info boxes, and so on) that are directly supported, plus the ease of directly embedding raw HTML (for things like diagrams and charts). But one challen…
Comment linking /blog/org-mode-publish.html
on “Blogging with org-publish in Emacs”Submitted (call/cc this-class) as a story · 3 points
HN discussionIt's possible to determine good values automatically: Measure your typing speed. You can do it in the background with: https://pavpanchekha.com/blog/emacs-keylogger.html and periodically update the latency parameters to be just over your natural typing speed.
Comment linking /blog/emacs-keylogger.html
on “Why Emacs Consult async searches feel slow and how to speed them up”Submitted Complex Square Roots in math.js as a story · 3 points
HN discussionAuthor here—it is from Tufte CSS. I have a blog post [1] about how floats work. It is a nice example of there being unintuitive and also more-intuitive ways to achieve things in CSS. These days I believe CSS Anchor Positioning provides a simpler way to do this, but I haven't used it yet. [1]: https://pavpanchekha.com/blog/css-floats.html
Comment linking /blog/css-floats.html
on “Should CSS be constraints?”Submitted Injection is a Display-level Problem as a story · 3 points
HN discussion
