MPE/iX Intrinsics Reference Manual (32650-90905)
24 Chapter2
Intrinsic Use
Functional Returns
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.