Is there a tutorial for custom widget in haskell?

[Abastro]

I just found this repository, which is a great example for writing a custom widget.
As quite a time has passed, I am curious if there are proper tutorial for implementing a custom widget. Thank you!

[noughtmare]

There is some more context for this repository in this haskell-gi issue: haskell-gi/haskell-gi#311

I don't think there is a tutorial for doing this with haskell-gi. I think this repository is the first attempt at making a custom widget.

[Abastro]

Oh, I see. I wished someone dedicated would have made a tutorial.