Top posts

Every blog post that took off on Hacker News, ranked by the votes of its best submission. 1,421 posts.

Software Engineering
2026
576

What is malloc doing, anyway?

malloc has a very nice and simple interface: you ask for a certain amount of memory, and you’re given a void pointer to your block of contiguous bytes that’s been magicked into existence. Once you’re done with it, you call free with the same pointer and the memory disappears into the ether.

581

An incoherent Rust

Coherence and the orphan rules are a frequent source of complaints about Rust, and a common topic of language proposals. This post covers most of the existing proposals around coherence and my vision for how we should solve coherence once and for all.

586

An agent in 100 lines of Lisp

Around 2000 I took an AI course at the University of Guelph. I don’t think I learned too much. We didn’t talk about neural networks, as far as I can remember. My end of term project was, I think, a pathfinding algorithm wearing an AI costume. There were certainly no discussions of transformers. No CUDA. No PyTorch…

590

Nix wrote half of my debugger

A few days ago I wrote about Rewind VM, a deterministic VM where every run of a Nix build is a pure function of its inputs, thread schedule included! I have been using it to find, reproduce and solve numerous race conditions in Nix builds, but it’s been making me feel a little crazy. What is this superpower, and why…

594

Racket v9.2

_posted by Stephen De Gabrielle and John Clements_ We are pleased to announce Racket v9.2 is now available from https://download.racket-lang.org/. As of this release:: The `match` form checks that when non-linear patterns (patterns where the same vari...