HP 3000 Manuals HP 3000 Manuals
Functional Returns
Certain intrinsics return a value to the calling program in functional
returns. These routines return a specified value type (for example,
16-bit signed integer, character, or 64-bit real) in its name.
Functional returns are declared in an assignment statement, where the
value returned is assigned to some variable of the same type as the
functional return. The symbol := is the assignment operator that is
"assigned the value of" or "receives the value of". The variable
receiving the functional return appears on the left-hand side of the
assignment operator, while the call to the intrinsic with a functional
return appears on the right-hand side.
For example, an intrinsic call description format for functional returns
appears below with the READ intrinsic, which returns to a 16-bit signed
integer indicating the length of the input read. The data type of each
variable is signified by a mnemonic above the variable name:
I16 U16A I16V
length:=READ(message,expected);
The READ intrinsic is read as a 16-bit signed integer procedure, where
message is a required 16-bit unsigned integer array passed by reference
and expected is a required 16-bit integer passed by value.
Other expressions that can contain calls to an intrinsic with a
functional return can appear in an output statement, the parameter list
of a procedure, or a conditional statement. Refer to the individual
programmer's language and reference manuals for details on functional
returns.