HLASM Language Reference

Figure 103. Substring Notation in Conditional Assembly Instructions
Used in Used as Example
SETC instruction
operand
AIF or SETB
instruction operand
(logical expression)
Operand
Part of
operand
Character value
in comparand of
character relation
&C1 SETC 'ABC'(1,3)
&C2 SETC '&C1'(1,2).'DEF'
AIF ('&STRING'(1,4) EQ 'AREA').SEQ
&B SETB ('&STRING'(1,4).'9' EQ 'FULL9')
Value
assigned to
SETC Symbol
ABC
ABDEF
---
The substring notation must be specified as follows:
'CHARACTER STRING'(e1,e2)
where the CHARACTER STRING is a character expression from which the substring is
to be extracted. The first subscript (e1) shows the position of the first character
that is to be extracted from the character string. The second subscript (e2) shows
the number of characters to be extracted from the character string, starting with the
character indicated by the first subscript. Thus, the second subscript specifies the
length of the resulting substring.
The second subscript value of the substring notation can be specified as an
asterisk (), to indicate that all the characters beginning at the position of the first
expression should be used. The extracted string is equal to the length of the
character expression, less the number of characters before the starting character.
The character string must be a valid character expression with a length, n, in the
| range 1 through 1024 characters. The length of the resulting substring must be in
| the range 0 through 1024.
The subscripts, e1 and e2, must be arithmetic expressions.
| When you use subscripted variable symbols in combination with substring notation,
| take care to distinguish variable subscripts from substring-operation subscripts.
| LCLC &DVAR(1),&SVAR,&C(1)
| &C(1) SETC '&DVAR(5)' Select 5th element of &DVAR
| &C(2) SETC '&SVAR'(1,3) Select substring of &SVAR
| &C(3) SETC '&DVAR(5)'(1,3) Select substring of &DVAR(5)
| &C(4) SETC '&SYSLIST(1,3)'(1,3) Select substring of &SYSLIST(1,3)
Evaluation of Substrings: The following examples show how the assembler
processes substrings depending on the value of the elements n, e1, and e2.
In the usual case, the assembler generates a correct substring of the specified
length:
Value of Variable Character Value
Notation Symbol of Substring
'ABCDE'(1,5)
ABCDE
'ABCDE'(2,3)
BCD
'ABCDE'(2,)
BCDE
'ABCDE'(4,)
DE
'&C'(3,3) ABCDE CDE
'&PARAM'(3,3) ((A+3)1) A+3
372 HLASM V1R5 Language Reference