Interfacing an external package with Clean

[Pascal Serrarens]

letz@rd.grame.fr wrote:
> 
> Hi,
> 
> We would like to interface our Midi  operating system MidiShare with the
> Clean language.

> Using the Hotclean utility, we were able to compile a link some external C
> functions.

> On the Macintosh, we tried to look at the Mac toolbox implementation, but
> we get rapidly very confused!
 
> Does anybody has an experience in developing this kind of interface?


Yes, I have implemented a interface to OMS (open music system) on the
macintosh, only the MidiOut part at the moment, but that will probably change
in the future.

I based the interface on the new message passing system, treating the MIDI out
port as a channel on which messages can be send.

MIDI programs look like this:

Start w
   #!  (midiOut, w) = openMidiOut w
       w            = send midiOut (NoteOn 1 60 127) w
       w            = sleep 60 w      // wait 60 ticks = 1 sec
       w            = send midiOut (NoteOff 1 60 0) w
   = w

I found this approch very convenient: I could write a standard MIDI file
player in two days.

Unfortunately, I am going on vacation for a month next week, so I can't do
much work on it.

More information on mesage passing for clean can be found in the 'Explicit
Message Passing for Concurrent Clean' paper, which can be found on my
home-page (http://www.cs.kun.nl/~pascalrs).
 
-- 
Pascal Serrarens
Concurrent Clean developer
University of Nijmegen, NL