MASPEGHI 2004 Mechanisms for Speialization, Generalization and Inheritance

Rapport de Recherche Projet OCL, N° I3S/RR-2004-15-FRInternational audienceMASPEGHI 2004 is the third edition of the MASPEGHI workshop. This year the organizers of both the ECOOP 2002 Inheritance Workshop and MASPEGHI 2003 came together to enlarge the scope of the workshop and to address new challenges. We succeeded in gathering a diverse group of researchers and practitioners interested in mechanisms for managing specialization and generalization of programming language components. The workshop contained a series of presentations with discussions as well as group work, and the interplay between the more than 22 highly skilled and inspiring people from many different communities gave rise to fruitful discussions and the potential for continued collaboration

Wishes for object-oriented languages

For a long time, I have liked to compare the parameter-passing modes of Algol 60 (some of you are probably old enough to remember) with speakers at scientific conferences. Namely, call by value vs. call by name in Algol, and authors of regular papers vs. invited speakers at conferences. This time I am lucky enough to be in the latter category; I also used to sa

Exheritance - Class Generalisation Revived

Abstract. We develop further the old idea that object-oriented languages could support also the inverse of inheritance (specialisation): generalisation or “exheritance”. It is easy as far as only interfaces are concerned, but attributes and method implementations cause problems. Renaming appears to be a very desirable language feature for exheritance. Combinations of inheritance and exheritance can be interesting and useful. 1. The basic idea Already in 1989, Claus H. Pedersen suggested that a generalisation mechanism be added to object-oriented languages, as a converse of inheritance, which typically means specialisation [Pedersen 1989]. The idea immediately looked nice and logical, but I have neither seen it developed further in the literature nor noted its adoption into any concrete language. On reading the paper again, I noticed a rather significant flaw (see Section 3), but it can be remedied. The paper [Pedersen 1989]is not explicitly aimed only at statically typed languages, but some of its suggestions are mainly relevant to these. Here, static typing will be assumed, but some points are relevant also to dynamically typed languages. One of Pedersen’s main arguments was that it is often natural to define more concrete an