[Biojava-dev] WalkerFactory code proposal

[David Huen]

On Sun, 10 Aug 2003, Matthew Pocock wrote:

> I'm all for it.
> 
> The only issue that comes to mind is handeling
> data-structures that are cyclic - I think that's
> beyond the scope of the Walker/Visitor design pattern,
> but needs to either be made part of the scope or
> documented as a limitation.
> 
I've come across one other issue:-
Walker.walk(FeatureFilter filter, Visitor visitor)

is required for the Walker interface but it does hardwire to
FeatureFilter.

We could either:-
1) change to Object filter: bad for type checking but easy to implement.
We can runtime check it. :-(
or
2) define a marker interface WalkableFilter that marks filters that can be
walked: this will require FeatureFilter to inherit from WalkableFiler
though.

Which should we do?

Regards,
david