Re: Filters

[Richard M. Stallman <RMS at MIT-AI>]

   Such a "Filter" can do everything that a LISPM "optimizer" can -- if
   it's the intention of the LISPM community not to have the more general
   mechanism, then that seems reason enough to let the more general,
   user-oriented facility have a different name.

These filters are a good idea, and I wouldn't mind if we had them.
But one thing filters are not so good for is WORKING ONLY IN THE
COMPILER.  There is a definite need for transformations which apply
only in the compiler, and that's why I implemented the OPTIMIZERS
property.  By emphasizing the need for these, I'm not trying to oppose
also allowing transformations that work in the interpreter too.

THIS feature, the feature of transformations in the compiler only,
really does deserve to be called "optimizers".  The other feature, of
transformations that would work in the interpreter too, certainly
should not be called "optimizers".  If they are what you have in mind,
then we are talking about two different things and not really
disagreeing.