guile-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: The relationship between SCM and scm_t_bits.


From: Paul Jarc
Subject: Re: The relationship between SCM and scm_t_bits.
Date: Wed, 05 May 2004 10:58:51 -0400
User-agent: Gnus/5.110002 (No Gnus v0.2) Emacs/21.3 (gnu/linux)

Marius Vollmer <address@hidden> wrote:
> I haven't looked myself but I think that STRICTNESS == 2 wont put
> SCM values into registers or something.

Ah, ok.  Well, that depends on the compiler - maybe more recent
compilers are better with this.  (Though we still have to think about
older ones too for a while.)  The definition of SCM for STRICTNESS ==
2 also has the advantage that an SCM object can be accessed through an
scm_t_bits* pointer.

> Isn't there the added advantage with level 2 that it doesn't accept
> SCM values in conditions?

Oops, right.  I had only been thinking of getting a diagnostic when
using one type where the other specifically was expected -
assignments, function arguments, etc.

> Yes, to all.  We need it to store arbitrary pointers for smobs.  When
> you define a new smob type, you get to decide what to do with the
> words of the smob cell: you can use them for SCMs, or for anything
> else that fits into a SCM.

Hmm.  A union including void* would be perfect, if not for the
register problem.


paul




reply via email to

[Prev in Thread] Current Thread [Next in Thread]