pTAL Reference Manual (H06.03+)

Equivalenced Variables
HP pTAL Reference Manual—523746-005
11-19
Declaring Equivalenced Definition Structures
The code in Figure 11-5 on page 11-19 declares an extended indirect definition
structure equivalent to a previously declared extended indirect structure.
If the new structure is to occupy the same location as the previous variable, their
addressing modes must match. You can declare a direct or indirect structure
equivalent to the following previous variables:
If the previous variable is a structure pointer, the new structure is really a pointer.
Figure 11-5. Equivalenced Definition Structure for CISC Architecture
STRUCT .EXT xstrl;
BEGIN
STRING old_name[0:20];
STRING old_addr[0:50];
END;
STRUCT .EXT xstr2;
BEGIN
STRING new_name[0:30];
STRING new_addr[0:40];
END;
New Structure Previous Variable
Direct structure Simple variable
Direct structure
Direct array
Standard indirect structure Standard indirect structure
Standard indirect array
Standard structure pointer
Extended indirect structure Extended indirect structure
Extended indirect array
Extended structure pointer
ptr to xstr1
xstr1
.
.
.
ptr to xstr1
xstr1
.
.
.
Primary area of user data segment
VST315.vsd