Stream: ideas

Topic: self hosted compiler

Yorye Nathan (Mar 05 2022 at 11:48):

Are there plans to rewrite the compiler/editor in roc at some point?

Folkert de Vries (Mar 05 2022 at 12:07):

nope, roc is not the right language for that. Parts of the editor will be written in roc (plugins etc) but a full compiler in roc would just be slower than what we're currently making

Kesanov (Mar 22 2022 at 09:41):

Can you elaborate what are the planned limitations of roc, that will make self hosting slow?

Folkert de Vries (Mar 22 2022 at 10:00):

these are mostly limitations in mutability and control over memory allocation

Folkert de Vries (Mar 22 2022 at 10:01):

also roc does not have a first-class concept of multi-threading

Brian Carroll (Mar 22 2022 at 10:06):

It wouldn't be slow, it would just be slower than Rust, one of the fastest languages out there. Roc is higher level than Rust and gives you more guarantees and ergonomics than Rust due to immutability, pure functions, memory management, etc. We work hard to make the performance difference tiny but it's not zero.

Also I think often people are intellectually fascinated by self hosting and really really hope that this cool idea is also beneficial. But it doesn't necessarily get you much and it's several years of work.

Folkert de Vries (Mar 22 2022 at 10:07):

it's typically an excellent dog-fooding project that appeals to compiler writers. But we aim to have other such projects (editor plugins, build system, etc)

Kesanov (Mar 22 2022 at 16:44):

Doesn't roc support inplace mutation as an optimization?

Maximilian E (Mar 22 2022 at 16:52):

I think it does, as discussed in the talk about a performant functional PL for stuff like quicksort, which is a worst case for functional. Do you know the talk or am I off target?

Brian Carroll (Mar 22 2022 at 16:53):

Yes. Roc allows mutation in a smaller set of circumstances than Rust. And it is more implicit, rather than being a first class concept.

Maximilian E (Mar 22 2022 at 16:57):

@Kesanov here's the talk at the relevant spot, if you're interested: https://youtu.be/vzfy4EKwG_Y?t=872

Folkert de Vries (Mar 22 2022 at 16:59):

in particular in the type checker, mutation is essential

Folkert de Vries (Mar 22 2022 at 16:59):

for good performance

Folkert de Vries (Mar 22 2022 at 16:59):

and we just wouldn't have the fine-grained control that we'd need in roc

Last updated: Jun 16 2026 at 16:19 UTC