HLASM Language Reference

Values in Operands
Notes:
1. Spaces appearing between commas (without surrounding single quotation
marks) do not signify an omitted positional operand or an omitted sublist entry;
they indicate the end of the operand field.
2. Adjacent commas indicate omission of positional operands; no comma is
needed to indicate omission of the last or only positional operand.
The following example shows a macro instruction preceded by its corresponding
prototype statement. The macro instruction operands that correspond to the third
and sixth operands of the prototype statement are omitted in this example.
EXAMPLE &A,&B,&C,&D,&E,&F macro prototype
EXAMPLE 17,+4,,AREA,FIELD(6) macro instruction
Unquoted Operands
The assembler normally retains the case of unquoted macro operands. However,
to maintain uppercase alphabetic character set compatibility with earlier
assemblers, High Level Assembler provides the COMPAT(MACROCASE)
assembler option. When you specify this option, the assembler internally converts
lowercase alphabetic characters (a through z) in unquoted macro instruction
operands to uppercase alphabetic characters (A though Z), before macro expansion
begins.
Special Characters
Any of the 256 characters of the EBCDIC character set can appear in the value of
a macro instruction operand (or sublist entry). However, the following characters
require special consideration:
Ampersands
A single ampersand indicates the presence of a variable symbol. The assembler
substitutes the value of the variable symbol into the character string specified in a
macro instruction operand. The resultant string is then the value passed into the
macro definition. If the variable symbol is undefined, an error message is issued.
Double ampersands must be specified if a single ampersand is to be passed to the
macro definition.
Examples:
&VAR
&A+&B+3+&C1
'&MESSAGE'
&&REGISTER
Single Quotation Marks
A single quotation mark is used:
To indicate the beginning and end of a quoted string
In a length, type, integer, opcode, or scale attribute reference notation that is
not within a quoted string
Examples:
308 HLASM V1R5 Language Reference