Defining Data Structure Parameters in a Prototype or Procedure Interface
To define a prototyped parameter as a data structure, you must first define the layout of the parameter by defining an ordinary data structure. Then, you can define a prototyped parameter as a data structure by using the LIKEDS keyword. To use the subfields of the parameter, specify the subfields qualified with parameter name: dsparm.subfield. For example
* PartInfo is a data structure describing a part.
D PartInfo DS QUALIFIED
D Manufactr 4
D Drug 6
D Strength 3
D Count 3 0
* Procedure "Proc" has a parameter "Part" that is a data
* structure whose subfields are the same as the subfields
* in "PartInfo". When calling this procedure, it is best
* to pass a parameter that is also defined LIKEDS(PartInfo)
* (or pass "PartInfo" itself), but the compiler will allow
* you to pass any character field that has the correct
* length.
D Proc PR
D Part LIKEDS(PartInfo)
P Proc B
* The procedure interface also defines the parameter Part
* with keyword LIKEDS(PartInfo).
* This means the parameter is a data structure, and the subfields
* can be used by specifying them qualified with "Part.", for
* example "Part.Strength"
D Proc PI
D Part LIKEDS(PartInfo)
C IF Part.Strength > getMaxStrength (Part.Drug)
C CALLP PartError (Part : DRUG_STRENGTH_ERROR)
C ELSE
C EVAL Part.Count = Part.Count + 1
C ENDIF
P Proc E