CAL: A Language for Aggregating Functional and Extrafunctional   Constraints in Streaming Networks
  In this article we present the {\em Constraint Aggregation Language} (CAL), a declarative language for describing properties of stateless program components that interact by exchanging messages. CAL allows one to describe functional as well as extra-functional behaviours, such as computation latency. The CAL language intention is to be able to describe the behaviour of so-called boxes in the context of S-Net. However, the language would find application in other coordination models based on stateless components. 
Alex Shafarenko and Raimund Kirner
cs.PL cs.DC