This starts out as a fair comparison but evolves pretty quickly towards a one-sided recommendation for Ocaml. I'm quite sure that there are _some_ advantages of Rust that are not listed here and would be curious to learn more about them too.
Compiler Development: Rust or OCaml?
21–30 of 107 posts
Re: Compiler Development: Rust or OCaml?
#22I don't quite follow the algorithm here, but I'm not sure the `gensym` Rust implementation works as expected. `RefCell::clone` does not return a copy of the reference; it returns a new `RefCell` with the current `RefCell`'s value, resulting in duplicate IDs. However, a `RefCell` isn't even necessary here, since a `Cell` would do just fine - and you'd pass around a reference to that `Cell` instead of cloning it. It do…
> it seems a bit odd to complain about this when that's what Rust is for
that's the point of the article - rust gives you a lot of low-level control, but if you don't actually need that control then you're paying the cost in ergonomics for nothing.
Re: Compiler Development: Rust or OCaml?
#23Why does it seem like I'm hearing about OCaml all the time now? It could just be frequency bias but it wasn't that long ago that I'd never heard of it and now it seems to be getting a lot of attention online.
the ocaml ecosystem has been going through something of a renaissance over the last few years (i believe because the build and package management tooling hit some sort of inflection point with dune and opam respectively), so there's been a lot of increased interest in it. it was (imo, of course) always a very pleasant language to use, and produced small and fast executables; the tooling was what was really holding it back.
Re: Compiler Development: Rust or OCaml?
#24I skimmed the article, and comparing the two programs, yes, the OCaml one is shorter and more elegant. But it also reads like a math magic spell. There's no type annotations for me to figure out what the heck each term is. The naming conventions lean extremely terse. Perhaps it's my lack of experience with OCaml, but it doesn't feel as legible.
The Rust one reads like...well a program. A program that's not as beautiful, but is very much designed to be taken apart, debugged, improved, etc.
I fully agree that if you're writing pure, recursive, data structure manipulations, OCaml is likely a better fit. It's closer to mathematical notation and I see the elegance in that. But if I were to take that data structure manipulation and turn it into a compiler with thousands of lines that I navigate with an IDE, with logging, with annoying little edge cases, with dozens of collaborators, I'd choose Rust.
Re: Compiler Development: Rust or OCaml?
#25Earlier quoted context omitted.
i assume they're talking about an Arena Allocator https://blog.logrocket.com/guide-using-arenas-rust/
I figured as much but was unsure. So the gain is that you still take heap allocations, but you do it in a "novelty" heap allocator that you will probably dipose of entirely at some point?
Allocation happens roughly like this:
If current top of heap + allocation size > buffer size, allocate an extra buffer for the arena. Save the current top in a temp variable. Add the allocation size to the top Return the temp variable.
It's fast, and the amortized memory overhead per allocation is near zero because you don't need to track allocation sizes or free lists, since you only free the whole arena at once (one or more buffers).
It's ideal for anything where the lifetime of allocations is known to be roughly the same. E.g. a data structure you'll free all at once.
Re: Compiler Development: Rust or OCaml?
#26I skimmed the article, and comparing the two programs, yes, the OCaml one is shorter and more elegant. But it also reads like a math magic spell. There's no type annotations for me to figure out what the heck each term is. The naming conventions lean extremely terse. Perhaps it's my lack of experience with OCaml, but it doesn't feel as legible. The Rust one reads like...well a program. A program that's not as beautif…
I think it’s your inexperience talking here as programs in both languages here use mostly the same naming conventions and abbreviations, the main difference being that Ocaml is its usual terse and to the point while Rust is well far less terse
Re: Compiler Development: Rust or OCaml?
#27Real World OCaml book needs a second edition.
Re: Compiler Development: Rust or OCaml?
#28Earlier quoted context omitted.
Can you write an equivalent piece of code that shows why Rust wins here with more familiarity and leveraging the ecosystem? With compilers I don't think there is a huge amount of using the ecosystem. I think what TFA does is a good case study in trying to be objective: write it both ways and compare.
I'm just saying a compiler is a program, and while the more important things are heavy algorithm related, supporting libraries like those for error handling, etc. all still matter and add up. No problem if you disagree - just my perspective. This isn't so much an objective thing as it is a personal opinion.
Personally, it’s not so much that I disagree. It’s more that Ocaml has a top notch ecosystem for compiler writing. That’s probably by far its strongest point with library like Menhir having few equivalent in different ecosystem.
Not that there is anything wrong with Rust if you are ready to pay the price of having so much low level things to deal with.
Re: Compiler Development: Rust or OCaml?
#29I skimmed the article, and comparing the two programs, yes, the OCaml one is shorter and more elegant. But it also reads like a math magic spell. There's no type annotations for me to figure out what the heck each term is. The naming conventions lean extremely terse. Perhaps it's my lack of experience with OCaml, but it doesn't feel as legible. The Rust one reads like...well a program. A program that's not as beautif…
I think it’s your inexperience talking here as programs in both languages here use mostly the same naming conventions and abbreviations, the main difference being that Ocaml is its usual terse and to the point while Rust is well far less terse
Yeah isn't that my point? Rust isn't trying to be short or elegant. There's no zen of Rust. There are elegant aspects of Rust, but it's not a central goal. Whereas with OCaml it's trying to be elegant. It's encouraging people to write a program where you read it, go "wait, how does that work?", then re-read it and marvel at the beauty of it.
To be clear, elegance is important. A language absent of elegance would be a bore to write (cough Java cough). But too much elegance and it can eclipse the legibility of the language. No type annotations is elegant. Is it legible? Not in my opinion. But perhaps it is in yours.
Re: Compiler Development: Rust or OCaml?
#30Earlier quoted context omitted.
I'm just saying a compiler is a program, and while the more important things are heavy algorithm related, supporting libraries like those for error handling, etc. all still matter and add up. No problem if you disagree - just my perspective. This isn't so much an objective thing as it is a personal opinion.
Personally, it’s not so much that I disagree. It’s more that Ocaml has a top notch ecosystem for compiler writing. That’s probably by far its strongest point with library like Menhir having few equivalent in different ecosystem. Not that there is anything wrong with Rust if you are ready to pay the price of having so much low level things to deal with.
Can you explain what Menhir does better than other parser frameworks? For what it's worth, I'm not a huge fan of parser frameworks. I tend to prefer hand written parsers, either via a combinator library or fully manually.
Rust has a pretty darn good ecosystem too btw. chumsky for parsing, rowan for syntax trees, salsa for incremental computation, miette for errors, inkwell/walrus for code generation.