Using a preprocessor to implement a data manipulation language for a minicomputer data base system

This paper reports on the implementation of a powerful data manipulation language (DML) of a data base system for minicomputers. The technique of language preprocessing is employed: The preprocessor translates each DML-statement into an internal form; however, in addition to a mere translation of statements the preprocessor has the function of executing so called 'compile-time tasks', i.e. those subtasks of the evaluation of a DML-statement, which can be done at compile-time already. This processing takes place in the course of program compilation and thus the size of the run-time module as well as execution-times can be reduced. The data base system FADABS is used to illustrate this approach.