[PD-dev] Some (not so?) basic external questions

[Albert Graef]

Hi everybody,

I've been mostly lurking here until now, so let me just briefly
introduce myself as the guy from the computer music department at the
University of Mainz (Germany) who wrote the functional scripting
language Q (http://q-lang.sf.net/), as well as the interfaces between Pd
and Q and Yann Orlarey's functional DSP programming language Faust
(http://faust.grame.fr/). The LAC regulars among you might already know
me. ;-)

I have some questions I need to answer in order to further improve the
Faust and Q externals. After googling around and searching pd-dev for
quite a while I still haven't figured out how to do these things, so any
advice will be deeply appreciated.

1. Dynamic reloading of externals

I ran into this while teaching a Faust programming course last semester,
where we used Pd as a convenient environment to test and run Faust programs.

Right now, when we recompile a (Faust-generated) external, we need to
restart Pd so that it picks up the new dll (.pd_linux file). It would be
*very* convenient if there was a menu command to quickly reload all
loaded externals and reconfigure the affected objects. I can imagine
that this is not easy to implement, but it would certainly make the
edit/compile/run cycle for externals much much easier. :)

Even with the current Pd it might be possible to reload a dll through a
"wrapper" external, but that still leaves the problem of reconfiguring
the inlets and outlets of affected objects on the fly (which would be
quite useful for scripting externals as well). I've seen that this has
been discussed on the ml before, but I couldn't figure out whether this
already works in the current Pd, and how.

2. Patch environment

A problem I have with the Pd/Q external is that the embedded Q
interpreter can only load a single main script per process. So I would
like to be able to specify the name of that script somewhere in the
hosting patch, as it would be rather clumsy if the user had to specify
the same script name over and over in each [q] object. I see that the
[declare] object provides that kind of functionality, but AFAICT only
for Pd's search path and lib environment. It would be great if externals
(loaded beforehand with -lib) could hook into that mechanism in some
way, so that one could write something like, e.g., [declare -script
foobar.q] and have this information available when the external starts
creating objects. Is it possible to do this?

Many thanks in advance,
Albert

-- 
Dr. Albert Gr"af
Dept. of Music-Informatics, University of Mainz, Germany
Email:  Dr.Graef at t-online.de, ag at muwiinfa.geschichte.uni-mainz.de
WWW:    http://www.musikinformatik.uni-mainz.de/ag