Effects for "Environment-aware" Computations

We adapt the alias type technology to dealwith primitives supporting environment-awareness (that is, the ability to adapt the behavior of an object according to the capabilities of the environment). In particular, we propose a type and effect system for an imperative object-based calculus with a primitive for discriminating the presence or absence of the object's attributes. Both the shape of the environment which guarantees the correct execution of expressions and the effect of expression evaluation on the environment are specified via suitable aliasing constraints.