Re: Transient environment with standard functions

[Basa Centro]

I did think of one project that uses a Lisp (CL) to let you do CAD in an 
Emacs REPL, rather than a GUI, which is Gendl:

Demo:
https://www.youtube.com/watch?v=yTcxNaBKTOc

Repo:
https://gitlab.common-lisp.net/gendl/gendl

If you haven't seen it, it uses a declarative syntax to avoid some of 
the sandboxing issues needed for public model "commons", and I think it 
does have a constraint solver to do something similar to your graph.  It 
has web based tool to display models in X3DOM/WebGL.   It doesn't get 
enough attention, IMO.  Again it is something I wish we had in Guile or 
at least Scheme.

I myself have contemplated using an implicit modeling backend with 
Sussman et al's. propagator concept to do the constraint solving, but 
that is a ways off I am afraid.

(Basa)