A Methodology for Writing Class Contracts

One of the principles of Design by Contract is that contracts for software components must be written in a declarative way, using a formal, mathematically founded notation. When we apply the Design by Contract methodology in a naive and straightforward way, we risk ending up with unwanted duplication. In this paper, we describe a methodology for writing class contracts that avoids specification duplication and that gives rise to uniform class specifications with a clear and fixed structure. A Methodology for Writing Class Contracts Nele Smeets*, Eric Steegmans Katholieke Universiteit Leuven, Department of Computer Science, Celestijnenlaan 200A, 3001 Leuven, Belgium {Nele.Smeets, Eric.Steegmans}@cs.kuleuven.ac.be *Research Assistant of the Fund for Scientific Research Flanders (Belgium) Abstract. One of the principles of Design by Contract is that contracts for software components must be written in a declarative way, using a formal, mathematically founded notation. When we apply the Design by Contract methodology in a naive and straightforward way, we risk ending up with unwanted duplication. In this paper, we describe a methodology for writing class contracts that avoids specification duplication and that gives rise to uniform class specifications with a clear and fixed structure. One of the principles of Design by Contract is that contracts for software components must be written in a declarative way, using a formal, mathematically founded notation. When we apply the Design by Contract methodology in a naive and straightforward way, we risk ending up with unwanted duplication. In this paper, we describe a methodology for writing class contracts that avoids specification duplication and that gives rise to uniform class specifications with a clear and fixed structure.