Back to the future Pointcuts as Predicates over Traces

Pointcuts in aspect-oriented languages can be seen as predicates over events in the computation of a program. The ability to express temporal relations between such events is a key feature towards more expressive pointcut languages. In this paper, we describe the design and implementation of a pointcut language within which pointcuts are predicates over the complete execution trace of the program. In particular, pointcuts may refer to events that will happen in the future. In this model, advice application is an iterative process that stops once a fixed-point is reached. On the negative side, we do not have a “killer example” for these kinds of pointcuts, there are still some serious limitations, and our implementation strategy is not suitable for a practical language. However, we think that considering pointcuts as predicates over the whole computation and advice application as a fixed point problem is an interesting new perspective on pointcuts for the FOAL audience.