HLASM Language Reference

Macro Instruction Format
Source Module
┌────────────────────────────────────────────────┐
Macro │ MACRO │
Definition
├────────────────────────────────────────────────┤
│ POSPAR &POS1,&POS2,&POS3 │
│ . ▲ ▲ ▲ │
│ . │ │ │ │
│ MEND │ │ │ │
├──────────────────────────┼─────┼─────┼─────────┤
│ . │ │ │ │
│ . ▌1▐ ▌1▐ ▌1▐ │
│ START │ │ │ │
│ . │ ┌──┘ ┌───┘ │
│ . │ │ │ │
Macro │ POSPAR ONE,TWO,THREE ▌2▐ │
Instruction │ . │
│ . │
│ END │
└────────────────────────────────────────────────┘
Figure 77. Positional Operands
Notes:
1. An omitted operand has a null character value.
| 2. Each positional operand can be up to 1024 characters long.
3. If the DBCS assembler option is specified, the positional operand can be a
string containing double-byte data. The string need not be quoted.
The following are examples of macro instructions with positional operands:
MACCALL VALUE,9,8
MACCALL &A,'QUOTED STRING'
MACCALL EXPR+2,,SYMBOL
MACCALL (A,B,C,D,E),(1,2,3,4)
MACCALL &A,''
The following list shows what happens when the number of positional operands in
the macro instruction is equal to or differs from the number of positional parameters
declared in the prototype statement of the called macro definition:
Equal
Greater than
Less than
Valid, if operands are correctly specified.
Meaningless, unless &SYSLIST is specified in definition to refer to
excess operands.
Omitted operands give null character values to corresponding
parameters (or &SYSLIST specification).
Keyword Operands
You can use a keyword operand to pass a value through a keyword parameter into
a macro definition. The values you specify in keyword operands override the
default values assigned to the keyword parameters. The default value should be a
value you use frequently. Thus, you avoid having to write this value every time you
code the calling macro instruction.
Chapter 8. How to Write Macro Instructions 301