To me, it is just plain broken, because the visitor can no longer decide what to visit and when. Of course, it is a decision of taste, but IMHO it should be the one or the other:

Either accept will recursively visit all nodes in the tree, or it should just call the single method. Not some in-between lame unknowable mixture.

To be brutally honest, I say it should always do the recursion itself, because otherwise, how is the visitor a visitor, if it effectively has to implement the traversal/iteration logic itself? And how is a visitor a visitor if it is to operate only on the Accepting node itself?

visitor = new Visitor(businessClass);
node.Accept(visitor);

then becomes a very expensive and illegible way to write

businessClass.method(node);

Well the rant is misplaced of course; I just wanted to thank you for carefully documenting my pain, which prevents me from doing the analysis myself

sorry you missed me last week!

I think that providing doughnuts would have the same effect!

However, that will be helpful to the motivated 80% of your developers who go to sessions and are receptive to new ideas. How do you get “in touch” with the other 20% who arguably have a much greater need for this sort of knowledge?

Disillusionedly yours,

Lasse

PS: that 80/20 split is of course extremely generous…