pest VS futures-rs

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

I had recently completed the first year of my Computer Science class at school and will begin my second year soon. My schools' class forces the use of Java programming language, and I absolutely hated it. So, over the course of a little less than a month, I wrote my own programming language, in Rust (objectively best programming language), using pest, to be as similar to Rust as possible, but compiling to Java.

I second pest.rs. Using it is fairly intuitive and there's also a live playground on their website which is great for quickly developing and testing your AST (abstract syntax tree) parser for whatever language you're implementing.

This is where you'll run into trouble. People who write parsing-related Rust crates generally write things like pest that expect their syntax to be defined completely at compile time so the parser can be run through the compiler's optimizers for best performance.

Give https://pest.rs a try.

For now I have used pest to generate an AST that borrows from the given input. But if I can manage to make the parser generic over the return type it may be worth a refactoring.

So this is actually better than true fairness (true fairness would lead to deadlock if a sender is forgotten). It is a pity that the there does not seem to be resources that document this design. There is this old thread where Carl provides some background, but I found it personally a bit hard to follow.

Is this still true after it switched to using FuturesOrdered?

Done.

You can use Streams, which are the async version of Iterators; They aren't stable yet, so you'll have to use a crate such as futures.

futures

For traits, like AsyncRead and AsyncWrite, go with the futures crate.

Here is the PR: https://github.com/rust-lang/futures-rs/pull/2551

Yield = wake the `waker_ref`. Avoiding the yield would be clone().wake().

That said, "poll immediately" isn't actually a thing nor was it ever a thing except in incorrect implementations.

Rust lacks an implementation of ReactiveX. futures/futures-signals seems to be the the ecosystem equivalent but I'm sure there'd be a lot of interest in an actual implementation.

The opposite problem exists as well. Many types are actually unwind safe, but do not get the autotrait. In that case authors would have to manually declare them UnwindSafe. Because this is rarely done, having an API with a trait bound T: UnwindSafe is rarely viable in terms of ergonomics. It now obliges client code to wrap all calls to your API in AssertUnwindSafe which, if they use types from third party libraries, obliges them to assert this is fine. example

Also, we plan to give users more control in the future. See https://github.com/rust-lang/futures-rs/issues/2207, https://github.com/rust-lang/futures-rs/issues/2295, etc. for this