PDP_GUILE - a scheme interpreter for pd/pdp

Copyright (c) by Tom Schouten <pdp@zzz.kotnet.org>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

The GNU Public Licence can be found in the file COPYING

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pdp_guile starts a scheme interpreter is started on pd's standard io. 
there is a simple send/receive interface in pd to communicate with the 
running scheme interpreter trough an input and output queue. pd can 
send messages, including pdp packets, to guile with the [ss tag] object.

guile can read using the (in) fuction, which returs a two element list:
the tag and the object (a float, a symbol, a list or a packet) i.e. if 
you connect a [pdp_v4l] object to a [ss some-tag-symbol] object and bang 
the v4l object, you can retreive the packet in guile using something 
like this:

(in)
=> (some-tag-symbol #<pdp 0 image/YCrCb/320x240>)

(in) retreives the oldest message from the input queue. if there are no 
more messages, (in) returns #f

guile can write using the (out tag object) function, which will send the
object to a [r tag] pd reciever. i.e. if you connect a 
[r some-tag-symbol] object to a [pdp_xv] object, you can display a 
packet (here contained in variable p) by doing:

(out 'some-tag-symbol p)


guile is connected to pdp's forth scripting language (pdp's "rpn 
calculator") using the (forth stack wordlist) statement. it returns the 
processed stack. i.e.:

(define p0 (make-pdp 'image/grey/320x240))
(define p1 (make-pdp 'image/grey/320x240))
(forth `(,p0 ,p1) '(add))
=> (#<pdp 2 image/grey/320x240>)


see pdp_guile.scm and pdp_guile.pd for an example of how pdp_guile 
could be used.

this is mainly for experimental interactive work and testing pdp's forth 
scripting. there's no documentation, apart from this file, the example 
and the source code. if you like to have more info, just drop me a 
line.

if you want to write externals in scheme, this is probably not for you.

requirements: libguile 1.6.x


enjoy,

tom