IBM AS/400 manual Using the PLIST Operation, the Fixed-Form Call Operations

				Using	the Fixed-Form Call Operations
If	insufficient		parameters	are	specified when calling a procedure,
when	an	unresolved	parameter	is	used by the called procedure. To a
you	can	either:

¹Check %PARMS to determine the number of parameters passed. For an example using %PARMS, see “Checking for the Number of Passed Parameters” on page 141.

¹Specify *OMIT in the result field of the PARM operations of the parameters. The called procedure can then check to see if the been omitted by checking to see if the parameter has value of %ADDR(parameter) = *NULL. For more information, refer to “Omitting Parameters” on page 139.

Keep in mind the following when specifying a PARM operation:

¹	One	or	more PARM	operations	must	immediately	follow	a	PLIST		operation.
¹	One or more PARM operations can immediately						follow	a	CALL	or	CALLB ope
	ation.
¹	When	a	multiple	occurrence	data	structure	is specified in the R
	PARM operation, all occurrences of the data						structure			are	passed
	field.

¹Factor 1 and the Result field of a PARM operation cannot contain

look-ahead field, a named constant, or a user-date reserved word.

¹ The following rules apply to *OMIT for non-prototyped parameters:

– *OMIT	is only	allowed	in	PARM	operations that immediately follows a
CALLB	operation	or in	a	PLIST	used with a CALLB.

–Factor 1 and Factor 2 of a PARM operation must be blank, if *O specified.

– *OMIT is not allowed in a PARM operation that is part of a *ENTR

¹ There are other restrictions that apply when using the PARM operat For a detailed description of these restrictions,ILE RPG for seeAS/400 the Reference.

For examples of the PARM operation see:

¹ Figure 47 on page 105

¹ Figure 42 on page 95

¹Figure 116 on page 239

Using the PLIST Operation

The PLIST operation:

¹Defines a name by which a list of parameters can be reference parameters is specified by PARM operations immediately following the operation.

¹Defines the entry parameter list (*ENTRY PLIST).

Factor 1 of the PLIST operation must contain the PLIST name. This name specified in the Result field of one or more call operations. If the entry parameter list of a called procedure, then Factor 1 must

Chapter 10. Calling Programs and Procedures151