Abstract

Despite Java's popularity, several practical limitations imposed by the language's type system have become increasingly apparent in recent years. A particularly glaring omission is the lack of a generic mechanism. As a result of this shortcoming, many recent projects have extended Java to support polymorphism in the style of C++ templates or Ada generics. One project, GJ [BOSW98], adds F-bounded parametric polymorphism [CCH 89] to Java via a homogeneous translation (such that only one class file results from each compiled source file), and produces bytecode that is compatible with the standard Java Virtual Machine. However while GJ's simple translation based on erasure allows for maximum interaction with existing Java code, the new parameterized types that it supports do not operate consistently with Java's semantics for lightweight reflection (i.e., checked type-casts and instanceof operations).

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