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Compiler Development: Rust or OCaml?

hirrolot.github.io

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Re: Compiler Development: Rust or OCaml?

#51

Post by arcticbull »

hardwaregeek wrote: post #30
brmgb wrote: post #28

Earlier quoted context omitted.

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.

Wow those library recommendations are fantastic, especially Chumsky. Thanks for sharing.

Re: Compiler Development: Rust or OCaml?

#52

Post by moomin »

brmgb wrote: post #36
hardwaregeek wrote: post #30

Earlier quoted context omitted.

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.

It can generate elegant and efficient parsers for LR(1) grammars. > I tend to prefer hand written parsers, either via a combinator library or fully manually. That’s common with people used to languages which provide poor parser generators.

I mean, it’s also common with people who value great feedback in their tools.

Re: Compiler Development: Rust or OCaml?

#53

Post by itishappy »

wredue wrote: post #13
ecshafer wrote: post #5

Earlier 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.

There was nothing objective about the article. The moment I saw seemingly random new lines in the rust for no reason, I knew there was going to be a “line counts!!!!” Sentence. When there was, I stopped reading because it was apparent that all matter of objectivity is completely missing. I don’t even like rust.

I like Rust but this isn't one of it's strong suits. The code in the article is what Rustfmt outputs (playground link below), so it's at least syntactically idiomatic.

https://play.rust-lang.org/?version=stable&mode=debug&editio...

Re: Compiler Development: Rust or OCaml?

#54

Post by jasinjames »

grumpyprole wrote: post #35
hardwaregeek wrote: post #24

I 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…

> There's no type annotations for me to figure out what the heck each term is You can add additional annotations in OCaml if you want, or just query the type of a term in Merlin. > 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. Why? OCaml supports logging and IDEs. Simple elegant code without the burden of m…

I like that term "Complexity Budget" a lot. I'm going to steal that one!

Re: Compiler Development: Rust or OCaml?

#55

Post by hardwaregeek »

arcticbull wrote: post #51
hardwaregeek wrote: post #30

Earlier quoted context omitted.

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.

Wow those library recommendations are fantastic, especially Chumsky. Thanks for sharing.

Yeah chumsky is fantastic, albeit with some rough compile errors and some unsafe. Still my favorite parser library by far and I’ve used a bunch by now.

Re: Compiler Development: Rust or OCaml?

#56

Post by [deleted] »

vidarh wrote: post #25
hurril wrote: post #18

Earlier quoted context omitted.

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 (on…

[deleted]

Re: Compiler Development: Rust or OCaml?

#57

Post by [deleted] »

reikonomusha wrote: post #43
wredue wrote: post #13

Earlier quoted context omitted.

There was nothing objective about the article. The moment I saw seemingly random new lines in the rust for no reason, I knew there was going to be a “line counts!!!!” Sentence. When there was, I stopped reading because it was apparent that all matter of objectivity is completely missing. I don’t even like rust.

It would be nice if somebody could offer what they consider to be an idiomatic Rust solution to this very routine problem in compilation if they believe the author is being intentionally deceiving. The Rust and OCaml code from the article looked decent to me. m

[deleted]

Re: Compiler Development: Rust or OCaml?

#58

Post by nequo »

josephg wrote: post #48

I normally love articles comparing programming languages at real tasks, but this article seems very low quality to me. The author clearly doesn't understand how rust thinks about programs. Instead, they're trying to pretend that rust is an alternate syntax for ocaml and being surprised to find it comes up short. The same article could easily be written the other way around. We could start with a high performance rust…

Your example is more concise but the error message "{term} invalid" is less descriptive than the author's.

What would be the idiomatic way for the function `eval` to provide good error messages in Rust?

Re: Compiler Development: Rust or OCaml?

#59

Post by timeon »

reikonomusha wrote: post #43
wredue wrote: post #13

Earlier quoted context omitted.

There was nothing objective about the article. The moment I saw seemingly random new lines in the rust for no reason, I knew there was going to be a “line counts!!!!” Sentence. When there was, I stopped reading because it was apparent that all matter of objectivity is completely missing. I don’t even like rust.

It would be nice if somebody could offer what they consider to be an idiomatic Rust solution to this very routine problem in compilation if they believe the author is being intentionally deceiving. The Rust and OCaml code from the article looked decent to me. m

> The Rust and OCaml code from the article looked decent to me

> RefCell

I'm not sure.

Re: Compiler Development: Rust or OCaml?

#60

Post by tyg13 »

reikonomusha wrote: post #43
wredue wrote: post #13

Earlier quoted context omitted.

There was nothing objective about the article. The moment I saw seemingly random new lines in the rust for no reason, I knew there was going to be a “line counts!!!!” Sentence. When there was, I stopped reading because it was apparent that all matter of objectivity is completely missing. I don’t even like rust.

It would be nice if somebody could offer what they consider to be an idiomatic Rust solution to this very routine problem in compilation if they believe the author is being intentionally deceiving. The Rust and OCaml code from the article looked decent to me. m

I don't think anyone was claiming the author was being intentionally deceiving, just that they're not very good at writing idiomatic Rust.

The first thing I'd suggest, as someone who's done their fair share of Rust compiler dev, is to stop using `Box` and `Ref` everywhere. Terms should not own their child terms; the idiomatic way to handle this is to use an arena and typed IDs, and pass a reference to the arena when you need access to the underlying data from the ID.

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