Non-Conforming Inheritance: the SmartEiffel Experiment of a High-Level Mechanism

Non-conforming inheritance (NC-inheritance) is a mecha-nism recently introduced in the new Eiel denition. The NC-inheritance mechanism is similar to traditional inher-itance but it disallows polymorphism. This simple mech-anism appears to be useful in many situations because it allows the designer to capture more design decisions in the source code itself. Furthermore this mechanism helps com-pilers to statically remove more dynamic dispatch code. NC-inheritance incurs no type-system soundness problems even when arguments are redened covariantly or when the ex-portation is restricted in the subclass. Out of the Eiel world, the NC-inheritance mechanism can be useful to add a no-penalty and no-risk multiple-inheritance-like facility. For instance the Java language, initially designed for simple-inheritance, could be a possible candidate for an NC-inherit-ance extension