[compiz] Re: Extension languages and Compiz.

[Robert Carr]

It's worth noting that another alternative is ifdefing code for
specific interpreters in various plugins (and insuring the plugins
that need to set up the interpreter enviroment load first) and having
./configure --with-scheme --with-python --without-ruby. Or something
of the vein. But I don't think we really want this either.


On 4/26/07, Robert Carr <racarr at beryl-project.org> wrote:
> My recent work on Compiz-scheme has brought to my attention several
> problems preventing a real compiz extension language.
>
> Note that when I refer to an extension language, I am not referring to
> the ability to add plugins in some other languages, but more of
> something in the vein of emacs lisp.
>
> The major problem right now is extension languages are locked in to
> one plugin and what core exposes. What I mean by this is it's easy to
> add support for something like:
> (window-rule (make-rule (set-opacity-when (window-is tooltipp) 0.5)))
> However it's impossible to add support for something like:
> (scale-window-when (window-is negativep)).
>
> There are two possible solutions to this:
>
> 1. Add basic support for a specific interpreter in core. Core would
> expose wrapper functions around the interpreter to easily enable
> plugins to add C functions to the interpreter. On one hand, we
> probably want to avoid binding core to a specific interpreter, on the
> other hand this sounds rather pleasant compared to the alternative.
>
> 2. Add an interpreter interface, with wrappable functions for plugins
> embedding a specific interpreter to wrap. I think it is abundantly
> obvious why such an interface would be unreasonably complex and likely
> bug ridden, exposing no specifics of an interpreter to individual
> plugins, but still having conversion from interpreter types->native
> types (a variable number of arguments per function + return types),
> plus adding new types and other constructs is exceedingly difficult,
> and complex to the point where I don't think we would want it.
>
> Does anyone else have any thoughts?
>
> Regards,
> Robert
>