Return Values

A procedure that returns a value is essentially a user-defined function, similar to a built-in function. To define a return value for a subprocedure, you must

1. Define the return value on both the prototype and procedure-interface definitions of the subprocedure.
2. Code a RETURN operation with an expression in the extended-factor 2 field that contains the value to be returned.

You define the length and the type of the return value on the procedure-interface specification (the definition specification with PI in positions 24-25). The following keywords are also allowed:

DATFMT(fmt)

The return value has the date format specified by the keyword.

DIM(N)

The return value is an array with N elements.

LIKE(name)

The return value is defined like the item specified by the keyword.

LIKEDS(name)

The return value is a data structure defined like the data structure specified by the keyword.

LIKEREC(name{,type})

The return value is a data structure defined like the record name specified by the keyword.

PROCPTR

The return value is a procedure pointer.

TIMFMT(fmt)

The return value has the time format specified by the keyword.

To return the value to the caller, you must code a RETURN operation with an expression containing the return value. The expression in the extended-factor 2 field is subject to the same rules as an expression with EVAL. The actual returned value has the same role as the left-hand side of the EVAL expression, while the extended factor 2 of the RETURN operation has the same role as the right-hand side. You must ensure that a RETURN operation is performed if the subprocedure has a return value defined; otherwise an exception is issued to the caller of the subprocedure.