On Jan 31, 2008, at 1:39 PM, Lars Jensen wrote:
>> True enough - but this seems like extra work to me. Why not just keep
>> track of everything as you create it? That way you'll always know
>> what's going on instead of having to repeatedly cycle through all the
>> windows to find the one you want.
>
> "Keeping track of" is another way of saying "caching information
> about". Caching is an optimization. Premature optimization is bad
> because it increases complexity and therefore risk of bugs. Therefore,
> unless you have a need to keep track of something (e.g. for
> performance reasons), it's generally better practice to ask the system
> for current information.
>
> Put another way: always ask the system, and if the system needs to
> cache the info, it can. That way, the benefit of caching is spread
> while the complexity remains contained.
Yikes! So I shouldn't keep track of document windows when they are
created? It's not as if a document window is going spontaneously
materialize behind my application's back - document windows only come
into existence when my app creates or opens a document. And when I go
to shut down my application, I can cycle through each document object
and tell it to close its window (instead of cycling through all the
windows in memory, figuring out if they are document windows, and
sending them a close command). This seems to me to be the very
underpinnings of object orientation.
I agree that premature optimization can be bad, but when you are
dealing with a reference-counting garbage collector, I personally
think it's a good idea to know where your objects are. That doesn't
seem like an optimization to me, merely good accounting. On the other
hand, if you are dealing with a resource that is shared amongst
multiple processes - for example, USB-based serial ports that can be
easily unplugged- it is always good practice to reflect the current
state of the system.
Eric Williams
Oxalyn Software
http://software.oxalyn.com/
AE Monitor
http://software.oxalyn.com/AEMonitor/
_______________________________________________
Unsubscribe or switch delivery mode:
<http://www.realsoftware.com/support/listmanager/>
Search the archives:
<http://support.realsoftware.com/listarchives/lists.html>
|