Re: Transient environment with standard functions

[Basa Centro]

> Yes, the graph is equivalent to an s-expr (with subgraphs being nested scopes).
>
> The reason that I’m not just representing the graph as a single expression is
> for
> efficiency – I’m doing incremental updates and change tracking, so you can
> update
> one of the node's expressions and have the changes propagate through the graph
> with a minimum number of re-evaluations.
>
> A similar Python engine is documented here:
> http://www.mattkeeter.com/projects/graph/
Matt [and List],

Sorry if your reply bounced, I was having email issues today. :(

Wow, I think I finally comprehend what you are doing.  I seem to 
remember looking at the code for a 3D scene graph in Scheme--where 
escapes me right now.  I think they used Scheme "promises" to cache 
values, again a lambda technique.

In any event, if you are translating from Python, I would encourage you 
to rethink what you are doing in light of Scheme's facilities.  A 
constraint solver might be straight-forward, as well.  Scheme is really 
good at what you are trying to do, built-in.

[
And if anyone else has ideas on this topic of optimizing the update of 
an S-exp as Matt has explained--I would be interested too.  It would be 
awesome to have something like Matt's Antimony done in Guile, trust me:

http://www.mattkeeter.com/projects/antimony/3/
]

Have fun,

(Basa)