[fpc-pascal] multiple inheritence

[David Emerson]

On Sat 3 Oct 2009, dmitry boyarintsev wrote:
> t_double_list = class (t_list_frame)
> private
>   flist1  : t_list_frame;
>   flist2  : t_list_frame;
>   function internal_add (const class_in : class_type) : boolean;
> end;

The idea behind my concept of t_double_list is that it is essentially 
one list which is both sorted and sequential at the same time.

One of the great things about OOP is that it helps reduce coding 
redundancy. That was one of the primary objectives in my design: code 
the stuff for unsorted lists once, code the stuff for sorted lists 
once, and code the common ancestor stuff once. I don't want to have to 
maintain three nearly-identical versions of find_via_binary_search.

The construct you've created here and named "t_double_list" is not a 
list at all; rather, it is a container which holds two lists which must 
be maintained independently of one another. Instead of simply inheriting 
the methods I need, I must completely rewrite them as methods of the 
container class. So this really isn't what I'm looking for.

Thanks for replying, though!

For now I've just inherited from t_unsorted_list, redundantly adding the 
sorted_list stuff. Not at all the elegant solution I'm looking for, but 
it seems to be the best that can be done.

Cheers,
David