| theme | class | highlighter | fonts | ||||||
|---|---|---|---|---|---|---|---|---|---|
default |
text-center |
MaskRay |
|
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| use num_derive::{FromPrimitive, ToPrimitive}; | |
| use num_traits::{FromPrimitive, ToPrimitive}; | |
| #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, FromPrimitive, ToPrimitive)] | |
| #[allow(non_camel_case_types)] | |
| #[repr(u16)] | |
| enum SyntaxKind { | |
| L_PAREN = 0, // '(' | |
| R_PAREN, // ')' | |
| ATOM, // '+', '15' |
edmundsmith
/ writeup.md
Created
July 7, 2019 20:47
Method for Emulating Higher-Kinded Types in Rust
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: