Optimizing Dynamic Class Composition in a Statically Typed Language

In statically typed languages the set of classes and similar classifiers is commonly fully determined at compile time. Complete classifier representations can then be loaded at run-time, e.g., from a an executable file or a class file. However, some typing constructs—such as virtual classes—enable a type safe treatment of classifiers and their associated types and instances, even in the case where classifiers are created dynamically. This opens the opportunity to make dynamic class computations available as an integrated part of the language semantics. The language gbeta is an example where this is achieved based on mixins and linearization. In this paper we focus on the virtual machine related challenges of supporting dynamic class composition. In particular we present some core algorithms used for creating new classes, as well as some performance enhancements in these algorithms.