pTAL Reference Manual (H06.03+)

Statements
HP pTAL Reference Manual—523746-005
12-19
DROP
DROP
The DROP statement removes either a label (from the symbol table) or a temporary
variable that was created by the statement USE on page 12-45.
identifier
is the identifier of either a label or a temporary variable.
Dropping Labels
You can drop a label only if you have already declared the label or used it to label a
statement. Before you drop a label, be sure there are no further references to the label.
If a GOTO statement refers to a dropped label, a run-time error occurs. After you drop
a label, you can, however, use the identifier to label a statement preceding the GOTO
statement that refers to the label.
Example 12-16. DO-UNTIL Statement With Hardware Indicator
INT exit_loop;
...
exit_loop := FALSE;
DO
BEGIN
...
READ(...);
IF <> THEN exit_loop := TRUE;
END
UNTIL exit_loop;
Example 12-17. DO-UNTIL Statement With GOTO Statement
DO
BEGIN
...
READ(...);
IF <> THEN GOTO out;
END
UNTIL false;
out:
...
DROP identifier
,
VST047.vsd