[fpc-pascal] Visitor pattern (was: Weird interface behavior)

[Juha Manninen]

Michael Van Canneyt kirjoitti sunnuntai 23 tammikuu 2011 17:41:13:
> On Sun, 23 Jan 2011, leledumbo wrote:
> > WARNING: it won't be simple
> > 
> > I'm using visitor pattern in my project and to the best of my knowledge,
> > the visitor should be implemented as an interface.
> 
> Why ?
> tiOPF uses the visitor pattern extensively, and it is implemented as a
> class.

Is this visitor pattern something that I should care about?
I have programmed quite much and never needed it.

I found many Java examples from internet and they all were good examples of 
"over-engineering" IMO. A simple thing made complicated.
Virtual methods or method references (kind of event handlers) solve those 
cases in a cleaner way.

Guess I need to study tiOPF finally. It is on my ToDo list anyway.

Juha