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:

charlietran

-- TerminalVim.app
-- This creates a shim Application that will enable you to open files from the Finder in vim using iTerm

-- To use this script: 
-- 1. Open Automator and create a new Application
-- 2. Add the "Run Applescript" action
-- 3. Paste this script into the Run Applescript section
-- 4. Save the application as TerminalVim.app in your Applications folder
-- 5. In the Finder, right click on a file and select "Open With". In that window you can set TerminalVim as a default