Procedure Call and Return Statements

To call a procedure, use one of the following two forms:

1) <procexpr> "(" { <arg> "," ... } ")"
     where
   <arg> = [ <argname> ":=" ] <expr> 

2) EVAL <expr>

The first form is used to call a proper procedure (one that does not specify a return type and thus has no return value). The second is used to call a function procedure when you want to throw away the return value. For example:

IO.Put("Hello");    (* Call a proper procedure *)
EVAL IO.EOF();      (* Call a function procedure and throw away result *)

To return from a procedure, use the following statement:

RETURN [ <expr> ]

The RETURN statement is used inside procedures only to return control to the caller. A return value must be supplied if the procedure is a function procedure, but may not appear if the procedure is a proper procedure.