Xerox 6180N Using LCDS Print Description Language - Page 181

3. Using logical processing Logical, or special, processing enables you to specify logical functions that will be performed on a record or a set of records. During job processing, the system tests the value of a specified test expression and directs the flow of processing based on the result of the test. In order to specify a logical processing function, you must define constants (character strings or values) for which the system will look in the job data records, and the criteria (such as "equal," "greater than," and so forth) that will be used to compare the record to the specified constant. Types of commands for logical processing Two types of commands are used to specify logical processing: • Constant definition commands. Two commands, CRITERIA and TABLE, define the constants or conditions in the job for which the system will test during job processing. • Logical processing commands. These commands specify which criteria the system will test for, and the action the system will perform when it encounters one of these criteria. Coding order of command types When you are creating a JSL that uses logical processing, you code the component commands in the following order: 1. Code the TABLE command first to define your constants (if any are needed). These must precede the CRITERIA CONSTANT command that references them. 2. Code the CRITERIA commands next. These commands must come after the tables they reference. 3. Code the logical processing commands after you have coded the CRITERIA commands that they reference. Using LCDS Print Description Language 3-1