The Lone Lisp Heap

NetMageSCW•about 3 hours ago

Flashbacks to when I implemented a new storage system for a Lisp/Prolog system while porting the core code from Pascal to C. We stuck with linked list of pages so we could keep pointers and gain some speed over array indexing for every object access.

matheusmoreira•about 2 hours ago

That's cool! Can you post more details? In my benchmarks the contiguous heap dramatically improved cache utilization. How did you obtain higher performance with linked lists?

PaulHoule•about 5 hours ago

You can learn a lot developing a language and runtime but you will reach a point when you'll realize you can go back and do it all better.

matheusmoreira•about 4 hours ago

No doubt. The second attempt is always better. My initial plan was to write a complete first implementation in C so that it's always possible to bootstrap the language, then write a compiler inside the lisp itself, or write a Rust version. Hope I somehow manage to do it all before I die of old age.

zabzonk•about 3 hours ago

> The second attempt is always better.

Um, see The Second System Effect.

https://en.wikipedia.org/wiki/Second-system_effect

matheusmoreira•about 3 hours ago

Lone itself is a second system: it's the spiritual successor of liblinux. I suppose the scope did increase... I'll try to be careful.

exe34•about 3 hours ago

Aha I've been semi-vibe-coding a scheme for esp32c3 and linux at the same time, and forgoing the libc too, so baremetal c. I went with a slightly awkward approach for allocation, with heap being seen as pages, and within pages, fixed size objects of size 8, 16 or 32 bytes. A pair is two words, and either bitpacked or pointer to another object. I'm not far in, vaguely following the Peter Michaux approach.

cultofmetatron•about 2 hours ago

this is my favorite thing about agentic coding. its super easy to build a v1 and get the system to a point where it does what you want which means you learn what you need for the v2 much faster

mhb•about 1 hour ago

Also building furniture.

The Lone Lisp Heap

⚡ Community Insights

Discussion (9 Comments)Read Original on HackerNews