Eiffel: A language and environment for software engineering

Abstract The Eiffel language and environment address the problem of building quality software in practical development environments. Two software quality factors were deemed essential in the design of the language: reusability and reliability. They led to the following choices: language features that support the underlying bottom-up software design methodology; modular structures based on the object-oriented approach, with support for both generic parameters and multiple inheritance (including a new extension, repeated inheritance); automatic storage management; highly dynamic execution model; support for polymorphism and dynamic binding; fully static typing; information hiding facilities; assertions and invariants that may be monitored at run-time. The Eiffel programming environment, using C as an intermediate language, supports separate compilation of classes and achieves a good run-time performance in both space and time. The environment takes care of automatically recompiling classes as needed after a change, ensuring that only up-to-date versions of classes are used, but avoiding unnecessary recompilations. A set of tools is provided to support the development of sizable software systems. An important part of the environment is the library of reusable classes. Significant extracts of this library are given in the appendix to this article, providing a set of model reusable software components, carefully designed for robustness and extendibility.