Re: Gtk2::TreeModel - foreach

[muppet <scott asofyet org>]

On Nov 19, 2009, at 4:15 PM, Jeff Hallock wrote:

> > -----Original Message-----
> > From: gtk-perl-list-bounces gnome org [mailto:gtk-perl-list- 
> > bounces gnome org] On Behalf Of Zettai Muri
> > Sent: Thursday, November 19, 2009 3:56 PM
> > To: Martin Schlemmer; gtk-perl-list gnome org
> > Subject: Re: Gtk2::TreeModel - foreach
> >
> > Where does the $user_data (scalar) part of the method come into play?
> > Is it possible to get an extended example that shows how this is  
> > used?

> > Is this data within the ListStore or some other data passed to the  
> > method?  How does the method act on this data?
> >
> > Again thanks for the help.
>
>
> If you supply $user_data - then you it will be passed in as the last  
> argument to the ForEach function.

If you're thinking, "but i can just use a closure for that", then  
you're already thinking perlishly.

The C api has user data pointers all over the place, because C doesn't  
have closures.  In perl, you get the option of using a closure or  
passing different parameters to a single function.  You'd choose to  
use the single function plus user data instead of a closure in a  
situation in which the closure would introduce a reference cycle.   
Pretty much any other time, you'd use a closure.


--
I can't believe i'm having to arbitrate who gets to have what dress on  
whose monkey.
  -- Me, exasperated at the ridiculousness of parenthood.