While we're at it, I'd like to mention the ceammc library, that can be installed in Vanilla (or you can use it as part of the Pd-Ceammc fork) and carries extra data types. For reference, see
https://periodicos.unespar.edu.br/vortex/article/view/6783/4805
They have a data type for nested lists (with the same syntax as Lisp using parenthesis) and dictionaries (whose syntax is a little bit python-like, using brackets and the ability to load/save JSON files).
There are yet other data types and I think that adding that many more is kinda overkill (like a data type just for envelopes), but anyway, it's interesting and I'm getting inspired to add both (nested lists and dicts) into ELSE, I just don't really think I'd need to create a new data type into Pd for this and add complexity to Pd's syntax. I guess that maybe I can only deal with special syntax for nesting lists and dictionaries...
And now that we're also talking about adding these to Vanilla, I wonder and would like to know if the idea is to expand the data types and complexity of the syntax, or if it's also just a matter of syntax.
Cheers