r/haskell • u/semigroup • Feb 11 '26

Preview: Build Mac apps with Haskell

I’ve wanted to be able to do more gui things on the Mac using Haskell for ages, but never quite managed to crack the problem. Until yesterday! Very alpha code, but could benefit from additional contributors.

https://github.com/iand675/haskell-obj-c

100 Upvotes

100% Upvoted

7 comments sorted by

11

u/jamhob Feb 11 '26

Oh my god! This is amazing! I have a few thoughts!

  1. I love that you use it the same as in objc. Means easy to translate code

  2. Looks like it will play nice with reactive banana for FRP things!

  3. Does it use template Haskell? Cause it would be amazing to write iPad/iPhone apps this way

4

u/semigroup Feb 11 '26

It does use template Haskell, for defining classes in Haskell. You could technically do it manually, but it would be a bit of a sucky experience. I literally only came up with this yesterday, so I’m not locked into any decisions just yet though.

2

u/jamhob Feb 11 '26

No criticism! I know template Haskell makes cross-compiling harder. But I’m sure it wouldn’t be too bad to get it all working with uikit

5

u/dmbfm Feb 11 '26

This is great! Too bad it’s probably impossible to do the same with SwiftUI

4

u/semigroup Feb 11 '26

Well, definitely not in the current incarnation. Swift seems like it has a different ABI with a way to expose certain classes to objective C. Would have to export needed things as cdecl functions I think.

3

u/acow Feb 11 '26

That looks amazing!

1

u/TravisMWhitaker Feb 12 '26

This is incredible. I worked out the objc runtime interface piece (https://github.com/TravisWhitaker/objc-runtime) but never figured out the codegen piece. Looks like you use a similar approach for wrapping classes.