Recently I split the repository with my port of the Elm compiler into the following three repositories:
- elm-compiler-in-elm: contains only the compiler backend, but no UI
- elm-compiler-in-elm-ui: adds a simple
elm reactor-like user interface (the same as before) - elm-repl-worker: an Elm
Platform.workerthat runselm replinternally
The REPL worker is kind of new. It allows you to integrate the Elm REPL into your Elm app. You send the user’s input to the worker via one port and get the REPL’s response back via another port. The repository contains a simple Elm app to test it:
After you have loaded the entry page, you no longer need an internet connection. It even runs on my wife’s old Android 7 phone, but it’s a bit slow there…
I’m aware that documentation is almost non-existent 
I’ll be happy to answer questions in Elm Slack, Discord, or Discourse and hopefully add them to the documentation in the appropriate repository.