chicken-hackers
[Top][All Lists]
Advanced

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

Re: [Chicken-hackers] The use of the null-pointer and null-pointer? proc


From: Peter Bex
Subject: Re: [Chicken-hackers] The use of the null-pointer and null-pointer? procedures
Date: Wed, 11 May 2011 17:14:15 +0200
User-agent: Mutt/1.4.2.3i

On Wed, May 11, 2011 at 08:21:32AM -0400, Felix wrote:
> > On Wed, May 11, 2011 at 05:25:12AM -0400, Felix wrote:
> >> > I was wondering what use does (null-pointer?) has.
> >> 
> >> Historical. I will deprecate.
> > 
> > Thanks, Felix.  I noticed the documentation says
> > "Another way to say (address->pointer 0)".  Should the address->pointer
> > procedure return #f when given 0?
> 
> No, otherwise you couldn't create a pointer object containing a NULL
> pointer... :-) I think we can expect a user to be able to code this.

I understand that this wouldn't be possible. But what is the reason
this has to be possible, considering null pointers are represented
as #f everywhere else?  For consistency it would make sense to return
#f here too, but of course you could also argue that it would be more
consistent to always return a pointer...

Ah well

Cheers,
Peter
-- 
http://sjamaan.ath.cx
--
"The process of preparing programs for a digital computer
 is especially attractive, not only because it can be economically
 and scientifically rewarding, but also because it can be an aesthetic
 experience much like composing poetry or music."
                                                        -- Donald Knuth



reply via email to

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