DML Precompiler-Directive Statements

This chapter presents syntax for precompiler-directive statements.

Function of Precompiler Directives

To use DML statements that request CA IDMS/DB and DC/UCF services, you must include precompiler-directive statements in your application program. Precompiler-directive statements:

Ensure that the assembler performs the proper expansion of DML statements into calling sequences appropriate to the CA IDMS environment
Identify the dictionary resources (subschema and/or maps) required by the program
Cause predefined source modules to be copied into the program from the dictionary
Generate source data description code

Summary of Statements

The DML precompiler-directive statements are summarized below:

@MODE initializes all global SET symbols that control the expansion of subsequent macros and DML commands into calling sequences appropriate to the CA IDMS/DB environment. You must code the @MODE directive before all procedural statements in the program, including DML commands for CA IDMS/DB and DC/UCF requests.
@INVOKE identifies all dictionary resources used by the application program. The @INVOKE statement must precede all procedural statements in the program, including DML commands for CA IDMS/DB and DC/UCF requests. This statement will generate non-executable source code when the MAP= operand is used for a map with multiple occurring fields.
@COPY IDMS copies the source data description code associated with CA IDMS/DB database records, the IDMS communications block, map records, and the map request block, as well as other predefined source modules and records, into the program from the dictionary at the location of the @COPY IDMS statement.
#MRB establishes a map request block (MRB), which is required for the mapping mode of terminal I/O operations. The MRB is a variable storage area in the application program and is used for communications between the program and the mapping compiler during a mapping I/O request.
#MAPBIND initializes the MRB for mapping requests issued by the application program. #MAPBIND generates executable code.
@SSCTRL generates the source data description code associated with the IDMS communications block in the program.
@SSLRCTL generates the source data description code associated with the LRC block in the program.

This section contains the following topics:

@MODE—initializes global SET symbols