Guardian Procedure Calls Reference Manual (G06.25+)

Introduction to Guardian Procedure Calls
Guardian Procedure Calls Reference Manual—522629-013
1-8
TAL Syntax for a Guardian Procedure Call
1 This indicates that the procedure is a function procedure; it
returns a value of the indicated type (in this case INT) when
referenced in an expression. You can specify the variable as
retval, status, error^code, or some other appropriate
name in other function procedure calls.
For function procedures that set the condition code, you must
declare the return variable as a simple variable. If you declare it
as a subscripted variable or a structure element, assigning a
value to it can alter the condition code.
“CALL” is a TAL CALL statement. Any procedure that does not
return a value must be invoked by a TAL CALL statement. In
addition, you can use a CALL statement to invoke a function
procedure if you do not need the returned value.
2 This is the name of the procedure that is called. The name is not
case-sensitive but otherwise must appear in the program exactly
as shown.
3 You must enclose the list of parameters in parentheses. Use
commas to separate parameters when there is more than one. If
you omit optional parameters, a placeholder comma (,) must be
present for each omitted parameter unless you omit it from the
end of the list. An optional parameter is indicated in a syntax
diagram by a parameter name enclosed in square brackets.
Two parameters separated by a colon are treated as a unit. If
they are optional parameters, both members of the pair must be
either present or absent. If you omit the pair within a list of
parameters, use only a single placeholder comma. In references
to the ordinal numbers of parameters, the pair is considered one
parameter.
4 The exclamation point indicates that a comment follows. The
comment can be an “i”, an “o”, or “i,o”, indicating that the
parameter is either an input (i) parameter, an output (o)
parameter, or both. In the example shown, “i:i” indicates that
nodename and length are both input parameters.
5 This line also indicates whether the parameter is an input
parameter, an output parameter, or both. In the example shown,
“input:input” indicates that
nodename and length are both
input parameters.
6 This line indicates the parameter type. In the example shown,
the types for
nodename and length are both given, separated
by a comma. The possible parameter types include: