[Maxima] common lisp complex numbers, also common lisp rational numbers

[Richard Fateman]

On 3/1/2012 1:30 PM, Steve Haflich wrote:
>
> One could of course modify an exiting CL implementation to make all the
> desired functions generic, but this would be a larger,
> more-destabilizing, and more performance-killing job than one first
> might think.  But I do agree it would be a neat thing to have!
a generic arithmetic system for CL with many (all?) the "data types" in 
Maxima
is posted in http://www.cs.berkeley.edu/~fateman/generic,   using mpfr for
bigfloats.  It also has some data types not in Maxima like intervals, 
quad-precision.
It  even has a compiler.  The difficulty remains that many of the 
coercions are
not obvious.  what do you do with interval + complex + symbol.  etc.

This code is more of a proof of concept than otherwise. Though I've used
parts of it repeatedly.  It uses allegro common lisp / foreign function 
interface
for some things; this can be run in a free version,  or you can leave off
those pieces relying on external libmpfr.dll, libgmp, qd.dll