TAL Reference Manual

Equivalenced Variables
TAL Reference Manual—526371-001
10-7
Example of Equivalenced Definition Structure
Declaration
Example of Equivalenced Definition Structure Declaration
The following example declares an extended indirect definition structure equivalent to a
previously declared extended indirect structure:
Equivalenced Referral Structure
An equivalenced referral structure declaration associates a new structure with a
previously declared variable.
. (period)
is the standard indirection symbol and denotes 16-bit indirect addressing. An
absence of any indirection symbol (. or .EXT) denotes 16-bit direct addressing.
.EXT
is the extended indirection symbol and denotes 32-bit indirect addressing. An
absence of any indirection symbol (. or .EXT) denotes 16-bit direct addressing.
VST1007.vsd
.
.
.
ptr to XSTR1
ptr to XSTR2
XSTR1
.
.
.
XSTR2
Primary area of user data segment
Automatic extended data segment
STRUCT .EXT xstr1;
BEGIN
STRING old_name[0:20];
END;
STRING old_addr[0:50];
END;
STRUCT .EXT xstr2 = xstr1;
BEGIN
STRING new_name[0:30];
STRING new_addr[0:40];
VST1008.vsd
(
[
index
]
+
offset
-
=
referral
identifier
STRUCT
.
.EXT
previous-identifier
;
)