Re: 1.6.0 and guardians

[Michael Livshin]

[ sorry for late response, I was out of the country and purposefully
  avoiding computers. ]

Dirk Herrmann <address@hidden> writes:

> On 7 Sep 2001, Michael Livshin wrote:
> 
> > Dirk Herrmann <address@hidden> writes:
> > 
> > > I don't see the need for such a functionality, but given there is some
> > > sense in it (in interactive development), the possibility to provide
> > > 'guarded?' and 'unguard' functions seems to be a better solution, since it
> > > allows to achieve the same goals on an per-object base.  Further, it
> > > does not lead to 'destroyed' guardian objects hanging around.
> > 
> > do closed file ports bother you similarly?
> 
> They are a potential source for errors, yes.

I don't think you can meaningfully reconcile this particular fear with
using a latently-typed-language-with-side-effects. :)

> And destroyed guardians are as well.  We can't get around closed
> file ports because of R5RS, but IMO destroyed guardians are
> something we can avoid.

we can, by not providing a way to destroy them.  of course.  and we'll
be left with a potential for resource leaks.

> But, again, why do you prefer the destruction of a guardian over using
> 'guarded?' and 'unguard' functions to achieve the same goals on an
> per-object base?  In some previous mail you said this wouldn't do the
> trick.  Why not?

I fail to see *why* do I have to deal with this on a per-object base.
if it's a guardian I'm getting rid of, then it makes all the sense in
the world to to deal with the guardian itself.  how are `guarded?'
and `unguard!' any cleaner and/or more straightforward?

perhaps there was a context loss on my part, or maybe we are just
talking past each other?

confused,
--mike

-- 
Well, I wish you'd just tell me rather than trying to engage my enthusiasm,
because I haven't got one.