TAL Programmer's Guide

New and Changed Information
096254 Tandem Computers Incorporated iii
The TAL Programmer’s Guide gives guidelines for using TAL. This edition incorporates
new features introduced in the D20 release and corrects text in response to reader
comment forms.
This edition includes the following new features:
For INT, REAL, and UNSIGNED data types and parameter types, a width
argument can consist of any constant expression, including LITERALs and
DEFINEs.
FIXED(
*
) is now a data type and a parameter type.
A variable can have the same identifier as the encompassing BLOCK declaration.
In addition to the implicit block named #GLOBAL, TAL creates an implicit block
for each template structure declared outside a BLOCK declaration.
The compiler ignores extra commas in, or adjacent to, procedure attribute lists.
In CALL statements, the CALL keyword is optional.
The RETURN statement lets you specify a condition-code value and a return
expression.
$OPTIONAL, a new standard function, lets you conditionally pass parameters to
VARIABLE and EXTENSIBLE procedures.
DEFINETOG, a new directive, lets you create named and numeric toggles. It
leaves new toggles turned off but does not change the settings of existing toggles.
The IF, IFNOT, and ENDIF directives now support named toggles.
The operating system for Tandem NonStop systems, formerly called the Guardian
operating system, is now called the Tandem NonStop Kernel. This change reflects
Tandem's current and future operating system enhancements that further enable open
systems and application portability.