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Comment by camus2 | Hacker News Reader

what about rust for webapps? are there any frameworks out there?

Kinda, yes, but not really. Currently, the best http framework in Rust is rust-http (https://github.com/chris-morgan/rust-http) and it has the things needed for handling requests and sending responses. But as far as actual full featured web frameworks, there is only one that I know of (discounting mre since it hasn't been updated in a long time) and that's because I am the creator of it. oxidize (https://github.com/jroweboy/oxidize) aims to be an inherently safe and fast web framework inspired by several other frameworks, but I don't consider oxidize to be even in a pre alpha state right now (pre alpha to me means, don't try to write code with it cause it will change drastically in the near future). I've rewritten the code for it twice already and a third time is sitting in a branch that doesn't compile right now. Progress has been a little slow lately since it became a group project for a class of mine, and that meant that I needed to manage several people working on it rather than actually contributing code. Over the summer I hope to get it in a good state and then make a post about it and fill out documentation, make tests, submit it to techempower benchmarks, and other necessities.

Having said that, I'm not confident yet that you want to be coding a web site in rust. In the name of safety, rust's compiler can be very difficult to please and in the name of speed it doesn't compile blazingly fast as well. Some people may have a different opinion from me, but besides writing a web app to learn the rust language, what advantages for the web does rust give you that go or haskell doesn't? When you are writing a web app, developer productivity is priority number one (in my opinion), and having to fight the borrow/lifetime checker and trying to find out why your struct doesn't fulfil `Send` are not things I would like to have to do when I'm making a web site. The tradeoff will be that hopefully a web site written in rust will be both fast and concurrently safe, but you will be sacrificing developer productivity for the reasons mentioned above. Irregardless of those issues, I'm still very determined to make a rust web framework that is both fast and easy to develop for (probably by providing examples of common web idioms in oxidize so people can see how to do it), just, I want people that use my framework to be aware of the tradeoffs that they will make. In short, I consider oxidize an experiment in trying to make a powerful, expressive, and extensible web framework in rust, and along the way I've started to question whether this will have any practical applications, but in spite of that, I still am trying to achieve the previous listed goals.

What I like about it is that it's pretty devoid of macros. I'm curious as to how you are planning to handle the environment of the webapp (configuration, connection pool, business objects...), given that you settled for plain functions with a given signature.

Thats the rework that I'm working on! I'm debating between making a context trait and having the static function signature include a context instead of a request and the everything request related would be included/appended in the context, or having the user implement "controller" trait on their struct that has a method I will call after settling the routes (something like https://github.com/jroweboy/oxidize/blob/incoming/tmp/matchb... where maybe a macro can generate this method from the urls. Note that this code doesn't compile though :) While I was initially fond of the latter, it's been very painful to work with in practice and I don't see it actually working, so I think that I'll be testing out to see if I can rework the static functions to have a context. I think the hardest part is that I want to eliminate any need to have any static variables, but that means I have to store them all in a struct that requires Send to be fulfilled and thats more over head for programmers. In the near future, I will be looking into using the different parts of rust-http directly rather than implementing the server trait to see if I can gain any benefits from that :)

Personally, I'd be inclined to have the context separate from the request, since they're really two different things. Also, you could introduce a FromRequest trait (trivially implemented by Request, returning self) to allow the user to build structures directly from a request (and its converse ToResponse), giving your function a signature of:

    fn (context: Context, req: FromRequest) -> ToResponse

    trait FromRequest {
      fn from_request<'a>(req: &'a Request) ->  &'a Self;
    }


    impl FromRequest for Request {
      fn from_request<'a>(req: &'a Request) ->  &'a Request {
        req
      }
    }

This would remove a lot of boilerplate for well-behaved applications. You'll also need a notion of middleware, which I guess would take a Request and return either a ToResponse or a request (eg, an authentication handler ought to return the response immediately in case of authentication failure), and similarly on the way out, something taking a Response and returning a Response.

Ah, obviously this wouldn't work, from_request would need to return Self and not a reference for it work, which means some overhead in the case of Request, since you'd have to clone it.

Not really. A lot of the infrastructure has kept changing for a while (eg, the IO facilities were recently rewritten), so code for older versions of Rust (like [1]) fall behind and do not get updated anymore.

With Chris Morgan's rust-http library (which I think is also used by Servo), you should have the base on which to build a web framework. Somebody apparently wrote (and still maintains) a pure Rust Postgresql driver ([2]), so you could in theory write a simple CRUD webapp, if you're willing to write the routing yourself.

1: https://github.com/erickt/mre

2: https://github.com/sfackler/rust-postgres

At present it's largely Watch This Space.

The language isn't stable enough yet and there are still a few pieces that need writing, anyway.

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