Using interface definition languages to support path expressions and programming by contract

The paper describes how path expressions and programming by contract can be supported in interface definition languages (IDLs) without the need for any IDL extensions or new keywords. The programming by contract model described here contains extensions which allow clients to place constraints on method calls at runtime, to improve system reliability and performance. As no IDL extensions are used, this system can be incorporated into new and existing systems and improve the quality and reliability of distributed object oriented systems. An example of the specification and a demonstration of its use are also presented