Proceduralism and parallelism in specification languages

摘要

We discuss the advantages and limitations of the “nonprocedural” mode of expression, in the context of languages for programming, system specification, and database access. A language is introduced which has some relevance to all three of the above processes. The syntax of LEGOL is based on the relational algebra, but incorporates procedural control structures for use when the underlying application logic demands. Using this language, solutions can be suggested for some example stock-control problems which are difficult to handle in a purely non-procedural way.