COMPUTER LANGUAGE STRUCTURE FOR PROCESS CONTROL APPLICATIONS AND METHOD OF TRANSLATING SAME INTO PROGRAM CODE TO OPERATE THE COMPUTER

A language structure and translator specifically adapted for use in constructing computer programs for controlling chemical and physical processing. The translator converts to compilable code programs written as statements expressing control intentions or results. Each textual function and statement is expressed as a data structure which expresses the function, as configured, and the state and values most recently calculated for the relevant variables. Provision is made for treating the program structure (i.e., control connections, program order and components, etc.) as a part of the dynamic state of the application. Graphical symbols, or icons, are employed to draw the eye to critical features in the control program and to lead the eye through critical interrelationships among the several commands of a complicated control system. At the same time, the translator treats the keystrokes generating these icons as statements (i.e., commands) which define the relationships among other associated program statements (which are usually textual commands), to control the order in which the operations represented by those statements are executed.