pTAL Guidelines for TAL Programmers

Differences Between TAL and pTAL
pTAL Guidelines for TAL Programmers—527256-002
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DO_PTAL Directive
DO_PTAL Directive
The DO_PTAL directive enables features of the TAL compiler that provide compatibility
with pTAL. These features include changes and additions to the syntax as well as
changes to the run-time behavior of certain TAL constructs.
DO_PTAL
enables new syntactic features in TAL that support pTAL constructs.
SYNTAX
ensures that TAL constructs from product version D20 and later behave the same
as they do in earlier product versions.
NODO_PTAL
disables the features that DO_PTAL enables. This is the default.
POPDO_PTAL
pushes the current setting (DO_PTAL [SYNTAX] or NODO_PTAL) onto the
DO_PTAL directive stack. Does not change the current setting.
PUSHDO_PTAL
pops the top value from the DO_PTAL directive stack and changes the current
setting to that value.
For an explanation of directive stacks, see the pTAL Reference Manual.
DO_PTAL SYNTAX:
•
Enables procedure pointers
•
Enables overflow trapping control
•
Ignores NOWARN directives with arguments greater than 1000
Note. The TAL compiler accepts this directive as of product version D40. The native compilers
ignore it.
DO_PTAL
NODO_PTAL
POPDO_PTAL
PUSHDO_PTAL
VST003.vsd
SYNTAX