calculating with bfloats (was: stuff not in 5.13 branch)

> One thing I (and I think other users) would very much like to see is a
> global key  which transparently turns on and off arbitrary
> precision. I realize that this may require redoing some intrinsic
> functions, so it may take time to do.  Are any of the current lisps
> set up to do this?

This is not a matter of the lisp implementation. AFAIK bfloats are
implemented entirely within the maxima source.

If you don't use floats (use rationals instead) you get exact
arithmetic by default.

I think the main change would be to make the parser read floats as
bfloats. I don't really see the point of that.

> I have tried to work on individual variables and functions (at this
> point involving algebraic functions no worse than square roots) by
> declaring all variables and functions to be bfloat, but for some
> reason it doesn't work. Certain of the operations still come back as
> float.  Maybe the square root is the problem. I have been using
> cmucl. Is that a potential problem?

Do you have example sessions, that show this behaviour? Probably there
are some bugs. I'd fix the bugs rather than inventing a new global
switch.

The only problem I'm aware of in this context is the numer flag.
But you shouldn't need to use that, if you work with bfloats from
the beginning.

HTH,
Harald