At 03:00 PM 3/8/2001 +0000, David Mitchell wrote:
> > The C structure that represents a bigint is:
> >
> > struct bigint {
> > void *num_buffer;
> > UV length;
> > IV exponent;
> > UV flags;
> > }
> >
>[snip]
> > The C<num_buffer> pointer points to the buffer holding the actual
> > number, C<length> is the length of the buffer, C<exponent> is the base
> > 10 exponent for the number (so 2e4532 doesn't take up much space), and
> > C<flags> are some flags for the bigint.
>
>Err... what representation is enivsaged for bigints? I had assumed it
>would be (length*8)-bit 2's complement,
I was thinking maybe (length/4)*31-bit 2s complement to make portable
overflow detection easier, but that would be only if there wasn't a good C
library for this available to snag.
>but the the later bit about
>base-10 exponents and digits made me wonder if you were actually intending
>a string (or BCD) represenation?
It probably ought to be left undefined, in case we switch implementations
later.
>In either case, the PDD needs to make it clear. (And if the latter,
>then permission to say "yuk!")
Yep. (And who ever needed permission on a perl development list to say
"yuck"? Or anything else, for that matter... :)
>bignum perhaps also needs some clarification.
No doubt.
Dan
--------------------------------------"it's like this"-------------------
Dan Sugalski even samurai
[EMAIL PROTECTED] have teddy bears and even
teddy bears get drunk
