Re: packages, objection orientation, list of functions (was case sensitivity)

>>>>> "James" == James Amundson <amundson@users.sourceforge.net> writes:

    James> On Sun, 2004-10-10 at 16:52, Richard Fateman wrote:
    >> While we are keeping a list of system functions,
    >> (an index, even) let me suggest we also start a
    >> list of all possible error messages and where
    >> they come from.
    >> Some of the messages come from the underlying
    >> lisp system; whether these can be caught and
    >> made into Maxima messages in some "system independent"
    >> fashion is unclear to me.  Certainly it can be done
    >> in ANSI CL, with error handling, but maybe not
    >> in everyone's favorite lisp.

    James> Standardized error messages sounds like a promising idea. The only
    James> serious deviations from ANSI CL we allow these days are in GCL. The GCL
    James> developers are moving closer to the ANSI standard, so I don't think we
    James> need to worry about using the ANSI CL error handling.

I would certainly like to be able to use ANSI CL conditions.  

In the adaptive plotter, we have to use a gross hack that if the
called function causes an error, we return NIL to signal a "problem".
However, the error could have been caused by all sorts of things, like
the function not being defined, it didn't return a number (something
symbolic, say), or other stuff.  If the function could signal overflow
or undefined, we could handle that more gracefully instead of going
into an infinite loop trying to refine the plot grid when there was
actually an error in the function not related to numerical evaluation.

Ray