This way, simple lists can be specified via juxtaposition:
a b c
And then more complex lists
thing 1, thing 2, thing 3
and still more complex lists like
A complex thing; with data, and more data
can be specified in a way that is potentially still human-legible and easily editable.
Combined with ~instant feedback while typing and, ideally, a “brushing” system to allow selection of parts of the textual model via the linked drawing, I am hopeful that this can be solved resiliently, at least for the most common use cases.
(Part of why I am excited about OP’s work here though is that while I have done a fair bit in my own project on drawing a related kind of diagrams, I have myself only begun thinking about how to make the resulting drawings nicely stylable/themeable.)
[1] https://mstone.info/depict/ -> https://github.com/mstone/depict
It's a disappointment or even failure of our current language scanning and parsing tools or, really, the way we used them, that this is not an easy exercise.