The object-oriented style of programming facilitates program adaptation and enhances program genericness, but at the expense of efficiency. Automatic program specialization can be used to generate specialized, efficient implementations for specific scenarios, but requires the program to be structured appropriately for specialization and is yet another new concept for the programmer to understand and apply. We have unified automatic program specialization and inheritance into a single concept,

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... d implemented this approach in a modified version of Java named JUST. When programming in JUST, inheritance is used to control the automatic application of program specialization to class members during compilation to obtain an efficient implementation. This paper presents the language JUST, which integrates object-oriented concepts, block structure, and techniques from automatic program specialization to provide both a generative programming language where object-oriented designs can be efficiently implemented and a simple yet powerful automatic program specializer for an object-oriented language.