pTAL Reference Manual (G06.24+, H06.09+, J06.03+)

identifier
is the identifier of a previously declared procedure, subprocedure, or entry-point identifier.
param-name
is a variable identifier or an expression that defines an actual parameter to pass to a formal
parameter declared in identifier.
param-pair
is an actual parameter pair to pass to a formal parameter pair declared in identifier.
param-pair has the form:
string
is an expression of the type STRING . or STRING .EXT.
length
is an INT expression that specifies the length, in bytes, of string.
Use the CALL statement to call procedures and subprocedures (but usually not functions).
To call functions, you usually use their identifiers in expressions. If you call a function by using a
CALL statement, the caller does not use the returned value of the function.
Actual parameters are value or reference parameters and are optional or required depending on
the formal parameter specification in the called procedure or subprocedure declaration (described
in Chapter 14 (page 246)). A value parameter passes the content of a location; a reference parameter
passes the address of a location.
In a CALL statement to a VARIABLE procedure or subprocedure or to an EXTENSIBLE procedure,
you can omit optional parameters in two ways:
• You can omit parameters or parameter pairs unconditionally. Use an empty comma for each
omitted parameter or parameter pair up to the last specified parameter or parameter pair. If
you omit all parameters, you can specify an empty parameter list (parentheses with no commas)
or you can omit the parameter list altogether.
• You can omit parameters or parameter pairs conditionally. Use the $OPTIONAL built-in routine
as described in Chapter 15 (page 274).
After the called procedure or subprocedure completes execution, control returns to the statement
following the CALL statement that calls the procedure or subprocedure.
206 Statements