This chapter contains these topics:
To work with Data Item Formula Revisions
To understand Program Design Language (PDL) statements and syntax
To understand PDL editing, parsing, and source generation
Use PDL to create specifications within the Detailed Programming Facility that causes specialized source code to generate. Use PDL for calculations or comparisons. When the program generates, the program generator converts the code into RPG source code.
Enter PDL code prior to the standard code that the program generator creates. If you want the PDL code to follow the standard code for a field, enter the PDL code on the field immediately following the field with which it is associated. The program generator creates all source code for fields in alphabetical order.
CASE stores PDL in the User Defined Procedures file (F93109) with one record per formula. The User Defined Procedures Detail file (F93110) divides the F93109 file into statements. The F93110 file contains multiple records for each formula.
PDL checks variable definitions as follows:
Checks the variable to see if it is a keyword
Checks for the variable in the RPG program
If not in the program, checks to see if it exists in the Data Dictionary Repository
If not in the Data Dictionary Repository, the user must define the variable
The PDL uses:
Data Item Formula Revisions screen
Blocks of Statements
Comments
Assignments
Database Operations
Calls
Loops
Conditions
Miscellaneous Keywords and Syntax
Perform the following tasks:
Work with Data Item Formula Revisions
Understand PDL Statements and Syntax
Understand Additional PDL Operations