Featherweight Jigsaw: A Minimal Core Calculus for Modular Composition of Classes

We present FJig, a simple calculus where basic building blocks are classes in the style of Featherweight Java, declaring elds, methods and one constructor. However, inheritance has been generalized to the much more exible notion originally proposed in Bracha's Jigsaw framework. That is, classes play also the role of modules, that can be composed by a rich set of operators, all of which can be expressed by a minimal core. We keep the nominal approach of Java-like languages, that is, types are class names. However, a class is not necessarily a structural subtype of any class used in its dening expression. The calculus allows the encoding of a large variety of dierent mechanisms for software composition in class-based languages, including standard inheritance, mixin classes, traits and hiding. Hence, FJig can be used as a unifying framework for analyzing existing mechanisms and proposing new extensions. We provide two dierent semantics of an FJig program: attening and direct semantic...

• Type: Conference
• Year: 2009
• Where: ECOOP
• Authors: Giovanni Lagorio, Marco Servetto, Elena Zucca
• Keywords: ECOOP 2009, Inheritance Chain, Programming Languages, Sophisticated Composition Mechanism, Standard Inheritance