REALLY close stack - no, really

[Richard Gaskin]

John Rule wrote:

> Does this feature actually benefit anyone? In all of the years I have used
> MC or RR I have been fighting this 'Purge' annoyance (and I have lost some
> work because of it). I now just make sure that the 'Destroy' attributes are
> set (destroy window and destroy stack)...this works 'mostly', but not
> always. I wish it would just be taken out of the engine itself....when I
> close a window, I am closing it! If I want to keep it in memory, I will
> 'hide' it myself.

I agree that destroyStack should be on by default, but I very much 
appreciate that it gives us control over how we manage memory.

Just today I was working on a system in which it's necessary to keep a 
database distributed among 36 stackfiles, but each one is relatively 
small so collectively they don't take up much RAM.  Moreover, with the 
destroyStack set to true the lookups across multiple stack files slow to 
a crawl, but with it off those lookups are lightning fast but, unlike 
haaving them open and hidden, I never have to worry about messaging 
issues or special-casing them to exclude them from my Windows menu, etc.

In contrast, I have another app I've been working on which support 
multiple documents, and for that one I have the destroyStack set to true 
to completely "put down" a document when it's closed, so it completely 
mirrors traditional application behaviors.

When you cut your teeth on other systems without such options, yes, 
learning how to use destroyStack effectively takes about as long as the 
first time you learned about cantAbort or cantModify or any other useful 
stack property.

Ah, but once you get the hang of it the world is your oyster. :)

FWIW, while I've seen many questions on both of the Transcript lists 
about how to use destroyStack effectively, in practice I've found it to 
be very reliable.  It's an old property that's been field-tested in 
hundreds of apps for about a decade, so if there were issues with its 
reliability they would likely have been more prevalent.

I say this not to suggest that you're not seeing what you're seeing. On 
the contrary, my aim is simply to help get a better understanding of 
what you're seeing.

It may be the case that a bug was introduced in more recent versions 
that has made destroyStack less reliable.  It may also be that what 
you're seeing is a function of the IDE and not the engine.

For the latter, you can use the Message Box to verify a property 
setting, or more conveniently you could double-check it with something 
like my 4W Props utility (available in RevNet).

If indeed the property is set as the IDE shows but is not being honored 
by the engine,  if you can toss together a simple example that 
demonstrates this anomaly and post it to Bugzilla it'll likely be fixed 
ASAP.  The destroyStack property plays such a key role in so many system 
designs that it would be unlikely that such a bug would be tolerated for 
long if a good recipe is included with the bug report.

-- 
  Richard Gaskin
  Fourth World Media Corporation
  ___________________________________________________________
  Ambassador at FourthWorld.com       http://www.FourthWorld.com