(That aside, very excited!)
(That aside, very excited!)
I imagine in a visual environment, being able to make useful suggestions on potential ways to use/combine different nodes/types would help as well as an auto-complete for the user's intent.
I'm actually also a bit reminded here of MS Excel Power Query, which also offered a GUI for data transformation, see e.g. [this pic](https://blogs.office.com/wp-content/uploads/2015/07/6-update...).
I bring this up because I see you covered visualizing the steps, while they focused on showing the data (though after finishing a transformation the script could be generalized into a reusable function). I wonder if adding a dimension like that could be helpful for Luna as well.
If you target non-programmers, showing things as concrete as possible (e.g. their data transformed by whatever function they just pulled together) sounds like it might help make things even more accessible.
They wanted simplicity and to control the language and syntax -- not to tie themselves to some Haskell-like environment.