edmundsmith

Method for Emulating Higher-Kinded Types in Rust

Intro

I've been fiddling about with an idea lately, looking at how higher-kinded types can be represented in such a way that we can reason with them in Rust here and now, without having to wait a couple years for what would be a significant change to the language and compiler.

There have been multiple discussions on introducing higher-ranked polymorphism into Rust, using Haskell-style Higher-Kinded Types (HKTs) or Scala-looking Generalised Associated Types (GATs). The benefit of higher-ranked polymorphism is to allow higher-level, richer abstractions and pattern expression than just the rank-1 polymorphism we have today.

As an example, currently we can express this type:

Diggsey

Looking into the Future

futures-rs is the library which will hopefully become a shared foundation for everything async in Rust. However it's already become renowned for having a steep learning curve, even for experienced Rustaceans.

I think one of the best ways to get comfortable with using a library is to look at how it works internally: often API design can seem bizarre or impenetrable and it's only when you put yourself in the shoes of the library author that you can really understand why it was designed that way.

In this post I'll try to put down on "paper" my understanding of how futures work and I'll aim to do it in a visual way. I'm going to assume you're already somewhat familiar with Rust and why futures are a useful tool to have at one's disposal.

For most of this post I'll be talking about how things work today (as of September 2017). At the end I'll touch on what's being proposed next and also make a case for some of the changes I'd like to see.

If you're interested in learning more ab

jFransham

Achieving warp speed with Rust

Contents:

• Number one optimization tip: don't
• Never optimize blindly
• Don't bother optimizing one-time costs
• Improve your algorithms
• CPU architecture primer
• Keep as much as possible in cache
• Keep as much as possible in registers