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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.
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