Yield from function?

[Profile Anaysis via Digitalmars-d-learn]

I need to yield from a complex recursive function too allow 
visualizing what it is doing.

e.g., if it is a tree searching algorithm, I'd like to yield for 
each node so that the current state can be shown visually.

I realize that there are several ways to do this but D a yield 
version without additional threads would be optimal. I don't need 
concurrency or speed, just simple.