Re: PDD 4: Internal data types

[Hong Zhang]

> 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.

I believe Python uses (length/2)*15-bit 2's complement representation.

Because bigint and bitnum are complicated anyway, we should make the
them transparent and disallow direct field access. Some generic inline
functions and/or macros must be used to access individual digits.
The actual data structure should be defined the implementation,
and is irrelavent to rest of system. We can decide its size if
we really need.

Hong