DPLAN-A data base oriented programing ianguage

This paper describes the design of a language intended for use in a data base environment. The language is of interest for several reasons. It is used as a vehicle to introduce the concept of transformation grammar as a basis for describing a high level programming language. We will show that a transformational grammar may define a natural English-like language while providing an efficient method for language recognition. Another important aspect of the language is its data view, in that data files are the processing unit, rather than in dividual records. Finally, the language is well suited to the programming orientation of viewing a program in terms of data mappings, allowing a more structured approach to programming. The examples presented in this paper are framed in terms of logical data structures. Because of the modular nature of the language processor, any physical data organization and data base implementation can be supported. In particular, both CODASYL-type and relational data bases C 1,23 can be handled via the appropriate transformations. This paper has two basic goals. One is to describe the language in both theoretical and practical terms. This is done primarily through the use of examples. The second goal is the introduction of the linguistic techniques used to define the language. These include transformational grammars. The purpose is not to be tutorial, but to indicate the nature of the technique.