Re: [TCLCORE] Empty list is not a list -- using twoPtrValue for NULL type

[Alexandre F. <ale...@gm...>]

On Jan 17, 2008 2:29 AM, Kevin Kenny <ke...@re...> wrote:
> Alexandre Ferrieux asks about the code in GetBignumFromObj:
> > Now I'm having a hard time understanding this: what if the string rep
> > is not NULL (for example if the bignum has just been printed) ? It
> > would seem that in this case, the object is reset to a pure string,
> > namely that representing the bignum. While if it was NULL (for example
> > just after a bignum computation), the string rep is empty. Why that
> > dichotomy ? And why touch the ptrAndLong ?
>
> [...] There are quite a few cases where a bignum object is unshared,
> and where we know that it will be dismissed as soon as we're done
> with it.

Yes, I can understand this. But why the strange manipulations on the
string rep (with two very different outcomes depending on a "simple
twist of fate" -- presence/absence of a string rep previously), if we
know the object is just about to be freed by the Tcl_Obj scavenger,
which takes care of all cases of presence/absence of string ant int
rep ?

-Alex