Coeffects for MiniJava: Cf-Mj

We propose an imperative Java-like calculus where declared variables can be annotated by coeffects specifying constraints on their use, e.g., affinity or privacy levels. Coeffects are heterogeneous, in the sense that different kinds of coeffects can be used in the same program. This paper extends previous work by the authors in which a functional core of a Java-like calculus was considered. Java annotations are used to identify classes implementing coeffects and coeffects decorating variable declarations. Moreover, a prototype implementation of the type and coeffect checker is given.