[fpc-pascal] Re: Why this evaluates on "if" wrong ? (GMP)

Tom Verhoeff T.Verhoeff at tue.nl
Mon Oct 29 21:09:39 CET 2007

On Mon, Oct 29, 2007 at 06:36:11PM +0100, Micha Nelissen wrote:
> It's possible to create a type that stores the numerator and
> denominator, but then you would need to "simplify" to extract common
> factors on every calculation, otherwise it would quickly run out of
> range (Integer or whatever you choose). Extracting common factors takes
> exponential time, so it's quite slow. The range would be quite limited
> as well, it's as wide as the numerator.

In fact, the GMP (GNU Multiple Precision Arithmetic Library <gmplib.org>)
offers this and more.  Unfortunately, there does not seem to be a complete
FreePascal interface for it.  Maybe it is easy to adapt (if necessary?)
the GNU Pascal interface for GMP <http://www.gnu-pascal.de/gpc/GMP.html>.
I would be interested.

There is also an initial attempt <http://fjf.gnu.de/misc/gmpop.inc>
to make the GMP functions available as operators under GNU Pascal.
The (ultimate) goal is that you can simply write things like
r := (a + b) * c where a, b, and c have a GMP number type,
instead of writing things like mpq_add ( r, a, b ) ; mpq_mul ( r, r, c ) .

E-MAIL: T.Verhoeff @ TUE.NL     | Dept. of Math. & Comp. Science
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