Open AccessStrong typing of object-oriented languages revisited
Author(s) -
Ole Lehrmann Madsen,
Boris Magnusson,
Birger Møller-Pedersen
Publication year - 1990
Publication title -
daimi pb
Language(s) - English
Resource type - Journals
eISSN - 2245-9316
pISSN - 0105-8517
DOI - 10.7146/dpb.v19i326.6716
Subject(s) - parameterized complexity , programming language , subtyping , computer science , type (biology) , relation (database) , class (philosophy) , algorithm , theoretical computer science , mathematics , artificial intelligence , ecology , database , biology
This paper is concerned with the relation between subtyping and subclassing and their influence on programming language design. Traditionally subclassing as introduced by Simula has also been used for defining a hierarchical type system. The type system of a language can be characterized as strong or weak and the type checking mechanism as static or dynamic . Parameterized classes in combination with a hierarchical type-system is an example of a language construct that is known to create complicated type checking situations. In this paper these situations are analyzed and several different solutions are found. It is argued that an approach with a combination of static and dynamic type checking gives a reasonable balance also here. It is also concluded that this approach makes it possible to base the type system on the class/subclass mechanism.