Retain cycle

[nicklockwood]

I’m not at a computer right now so I can’t verify this, but it looks to me like your approach to handling forward references (using the Deferred class) might introduce a retain cycle.

My own Consumer library has a similiar design to yours, and I originally used a similar approach of using a class as a proxy for forward references, but I couldn’t find a way to break the cycle, because the parser enum is a value type.

One option is to wrap the parser enum in a class so it can be weakly referenced, but that seems like it would hurt performance, and it makes the API less elegant.

In the end I solved it by referencing using a string label instead of a pointer.