lalrpop VS chumsky

And some related parser tools: - https://github.com/kevinmehall/rust-peg - https://github.com/pest-parser/pest - https://github.com/lalrpop/lalrpop

lalrpop

Rust is a very nice langage for implementing compilers, and has a nice ecosystem for it (logos, rust-peg, lalrpop, astmaker -- this one is mine --, etc...).

rust-langdev has a lot of libraries for building compilers in Rust. Perhaps you could use these to make your implementation easier, and revisit it later if you want to build things from scratch. I'd suggest logos for lexing, LALRPOP / chumsky for parsing, and rust-gc for garbage collection.

Hi! For one of my projects I am currently using lalrpop (https://github.com/lalrpop/lalrpop/tree/master/doc/calculator/src), which is far from complete, but has the basic syntax I was looking for. I took some examples and worked around some lexer stuff but I’m currently happy with it. If you use it and have Intellij stuff installed, you can also use a plug-in for highlighting and SOMETIMES error checking. Otherwise, even VSCode had a great plug-in for highlighting!

How would you compare and contrast this with, say, lalrpop?

lalrpop is great. It's a completely different approach from nom, but for parsing a programming language, I would at least consider it. RustPython uses it.

I presume LALRPOP handles left recursion just fine.

I wanted to share an experimental side project I have been working on for some time. I constantly use commands like `jq` and `yq` for processing structured data in my day job and I was curious if a similar idea could be applied to images.

Another goal of mine was to get some exposure to with rust. I discovered the LALRPOP parser generator which really helped moved the project along (https://github.com/lalrpop/lalrpop)

The key point here is that we are going to depend on the lalrpop library to generate the parser based on the formal grammar we define. Note that we have it as part of the [build-dependencies] section and we only depend on a tiny utility crate called lalrpop-util at runtime. The reason for that is the main lalrpop "magic" would happen during the crate compilation (in the build.rs file) when lalrpop would generate the deterministic pushdown automaton based on our grammar. The code generation logic is not required to be part of our interpreter, we only need a few utility methods from the lalrpop-util for the automaton to operate. You might have noticed that we also enable the lexer feature of lalrpop, because we are going to use lexer provided by lalrpop as well (please refer to the Part I if you do not know what the lexer is).

I attempted to use this but was disheartened but the fact that it doesn't statically type node names. Tree Sitter doesn't either but it has much more of an excuse given that it targets C.

https://github.com/lezer-parser/lezer/issues/8

The dev seems mildly hostile to outside involvement too, so I moved on. These days I use Chumsky which is Rust rather than Typescript, but also way more awesome, if you can deal with the often incomprehensible compilation errors at least!

https://github.com/zesterer/chumsky

there’s also chumsky: https://github.com/zesterer/chumsky

We are using technique called parser combinator. And we are using a library chumsky to write parser combinators.

rust-langdev has a lot of libraries for building compilers in Rust. Perhaps you could use these to make your implementation easier, and revisit it later if you want to build things from scratch. I'd suggest logos for lexing, LALRPOP / chumsky for parsing, and rust-gc for garbage collection.

The examples that come with chumsky and the chumsky tutorial and guide all define their parsers using closures.

Parser: https://crates.io/crates/chumsky

chumsky's zero-copy rewrite has reached its first alpha release, and I have migrated my pep-508 parser to it, as suggested in my last announcement.

On my side, nom is still advancing well and a new major version is in preparation, with some interesting work a new GAT based design inspired from the awesome work on chumsky, that promises to bring great performance with complex error types. 2023 will be fun for parser libraries!

I am using chumsky because I like the API, but it doesn't support zero copy at the moment. Although efficiency is good to have, it is not my primary good. This will probably get supported once chumsky implements support for it (see upstream issue).

Checkout https://github.com/zesterer/chumsky or https://github.com/rust-bakery/nom