SPIL: A language for construction of reliable system software

Structured programming is gaining wide acceptance as a technique for increasing the reliability and understandability of software. Nowhere is the need for better software felt more keenly than in the area of systems programming. In the near future it is likely that systems will be programmed in structured programming languages, just as systems have been programmed in higher level languages in the past. This paper describes SPIL: a structured programming language intended to be used for system design and implementation. The paper discusses how the objectives of structured programming and system programming may be realized in a programming language, and delineates the influence of the objectives on the design of SPIL. The most important features of the language are briefly described. The paper concludes by evaluating SPIL as a language for system design and implementation.