rust-peg VS genawaiter

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

My peg crate is a parser generator that supports arbitrary token types as input. See https://github.com/kevinmehall/rust-peg/blob/master/tests/run-pass/tokens.rs for an example.

The one rust parser-generator I used is PEG

The two parser generators that I am aware of are lalrpop and PEG. There both great, and have seen some use by languages that have been written in Rust.

rust-peg

I wanted to create a parser for Apertium Stream. In 2014, I used Whittle in Ruby. If this year were 2001, I would use Lex/Yacc. Anyway, this year is 2021. I wanted to create this parser in Rust. I tried to find what is similar to Lex/Yacc. I found Rust-Peg. I found a link to Nom from Rust-Peg's document. My first impression was Nom example is easy to read. At least, its document claimed Nom is fast.

The peg crate has a resolved issue about this.

I don't really know that much about parsing and grammars, other than what I've learned about regular languages and expressions and context-free languages in a standard Theory of Comp course from my university. I basically just learned peg by reading the Wikipedia article on PEGs, reading the crate documentation to understand the syntax, and then looking at some of the peg examples on their GitHub to understand how it works in practice.

Yes, Letlang is translated to Rust and the runtime is implemented in Rust, using tokio and genawaiter. The compiler itself is also built in Rust.

(note that genawaiter itself doesn't support no_std environments, but there's a merge request for that.)

> `async` to make fake generators.

Genawaiter[0] is one of them.

[0]: https://github.com/whatisaphone/genawaiter

Are you aware of the genawaiter crate?

A warning though: genawaiter doesn't seem to be maintained. The last commit is 2 years old, and issues are not active (I opened one that I find somewhat critical: https://github.com/whatisaphone/genawaiter/issues/35).

There's e.g. https://github.com/whatisaphone/genawaiter, but you can also use yield directly (https://doc.rust-lang.org/beta/unstable-book/language-features/generators.html).

If you're interested in something that can be used right now, on stable, you should take a look at the genawaiter crate, it reimplements generators with async.