[PD-dev] pdlua: volatile objects...?

[Claude Heiland-Allen]

zmoelnig at iem.at wrote:
> hi list, hi claude.
> 
> using the great pdlua extension it is easy to create object(classe)s in lua.
> however, the class is registered on loading and then kept in memory of pd.

The problem is Pd doesn't give loaders the chance to load a class if it 
is already loaded, but there is a way around it, I think.

> for rapid prototyping it would sometimes be nice to be able to do a  
> "volatile" load (just like abstractions) of an object: so when i  
> change the code and re-instantiate the object, i will get a new version.

It's certainly possible, here's a quick hack method:


-- volatile.lua
volatile = pd.Class:new():register("volatile")

function volatile:initialize(s, m)
   dofile(m[1] .. ".lua")   -- note, only searches current dir!
   return run(self, m)
end


-- volatile-test.lua
function run(self, m)
   pd.post("just testing stuff")
   self.inlets = 0
   self.outlets = 0
   return true
end


Sorta works, but not elegant.  Should be possible to do it so that the 
volatile user code is minimally different from the normal user code. 
Something like

-- volatile-test.lua
pd.volatile(function()
-- normal class code here
end)

where pd.volatile(f) would munge the environment before calling the 
function argument, then unmunge the environment afterwards.  Munging 
would take the form of replacing pd.Class with pd.VolatileClass or so. 
All VolatileClass objects would have the same real class registered in 
Pd,, but the loader can keep reloading classes that are not found 
because no new classes are really registered.

> would this be easy to implement?

Not too hard, hopefully, but not trivial either.  It's a nice idea that 
would be useful, it's a pain having to restart Pd when testing.

Also I plan [lua] to have an inlet/method where you can send names of 
scripts to be executed, which could be useful for quickly modifying some 
classes/objects without having to restart Pd.


Claude