What comes in between predecessor and successor?

I'd like a good word for "current item in a succession of items".

Let's say I am looking ahead, towards my successor. Back behind me, I can also see my predecessor. What am I?

I'd hate to use the overly-verbose "current object of focus among a succession of such objects", and yet "current" doesn't quite cut it either. "Currentssor"?

The context is programming (coming up with descriptive variable names) but I'm really interested in what's true in general.

I think incumbent is what you're looking for.

holding an indicated position, role, office, etc., currently: the incumbent officers of the club.

(dictionary.com)

A locus is the position of a gene on a chromosome.

As part of a sequence, a locus has both predecessor and successor (either of which, as in any sequence, can be null).

When talking about, say, a linked list, I find it more elegant and concise to say the locus of the list iterator rather than the node to which list iterator is currently pointing.

Commenters have pointed out the hazards of borrowing an overloaded term like locus; if you want to use a more standard term, current element is well-understood.

You are a referrer referencing your predecessor and successor http://en.wiktionary.org/wiki/referrer