Overloaded vs variable?

Overloaded vs variable?

[Keith Seitz]

Hi,

In my ongoing effort to cleanup managedwin, I've noticed a trend to do 
things like:

Class ManagedWin {

   public method something {} { return 1 }

   public method frob {} {
     if {[something]} {
       _frob_it
     }
 }

Class MyWin {
  inherit ManagedWin

  public method something {} { return 0 }

}

This is supposed to dictate to ManagedWin not to frob MyWin. Question 
is: Why is this any better than just using a protected variable? It 
would seem to me to be a lot cleaner...

Keith

Re: Overloaded vs variable?

[Fernando Nasser]

I guess whoever wrote it had the following in mind (I am just guessing,
I was not around at the time):

MyWin::something can perform a calculation (check something) whenever
ManagedWin::frob is invoked.

I.e., cause the test for a condition specific to a subclass whenever the
base class method is invoked.  This could not be done with a variable
because the invocation is what is determining *when* the evaluation is
done.

I have no idea where this is useful in our code.  

Also, the degenerate case (a constant value) does map to a protected
variable.  It may be more clear to test for the protected variable than
to use method overloading in that case.  I don't have any strong
feelings about it.

As far as I am concerned feel free to change it wherever it makes sense,
if it is more to your taste.

Cheers,
Fernando

Keith Seitz wrote:
> 
> Hi,
> 
> In my ongoing effort to cleanup managedwin, I've noticed a trend to do
> things like:
> 
> Class ManagedWin {
> 
>    public method something {} { return 1 }
> 
>    public method frob {} {
>      if {[something]} {
>        _frob_it
>      }
>  }
> 
> Class MyWin {
>   inherit ManagedWin
> 
>   public method something {} { return 0 }
> 
> }
> 
> This is supposed to dictate to ManagedWin not to frob MyWin. Question
> is: Why is this any better than just using a protected variable? It
> would seem to me to be a lot cleaner...
> 
> Keith

-- 
Fernando Nasser
Red Hat Canada Ltd.                     E-Mail:  fnasser@redhat.com
2323 Yonge Street, Suite #300
Toronto, Ontario   M4P 2C9