Re: single or double cell?

[Dirk Herrmann]

On Fri, 2 Feb 2001, Keisuke Nishida wrote:

> At 01 Feb 2001 19:30:05 +0200,
> Michael Livshin wrote:
> > 
> > > Is there any convenient way to know whether a given smob uses
> > > a single-cell representation or double-cell?
> > 
> > SCM_GC_CARD_DOUBLECELLP (SCM_GC_CELL_CARD (obj))
> 
> This seems working, though I had to write rather
> 
>   SCM_GC_CARD_DOUBLECELLP (SCM_GC_CELL_CARD (SCM_UNPACK (obj)))

Well, obviously my last mail was not really correct, since there _is_ a
way to determine whether an object uses a single or double cell for its
representation :-)

However, what I rather meant is whether it makes sense to use this
knowledge outside of the gc and the corresponding types.  In the last year
or so, a lot of work has been put into guile in order to break up
dependencies between parts of guile, for example the dependency between
the gc and the type system.  Thus, I am very skeptical towards approaches
that introduce such couplings.

Best regards,
Dirk Herrmann