Projectional / structural web editors with Elm - Progress video

Hi all,

I created a video showing some progress on an API I’m working on to build your own projectional / structural editors with Elm. This is experimental at best. Yet, I was wondering if some of you might be willing to look at the project and provide feedback.
The video first shows an example editor for a simple state machine language, before looking at the code to build it.

Notice that I haven’t found the time to add a README or anything like that to the repository. If I decide to follow up on this project more seriously, I will certainly do that.

I appreciate any feedback.