DUP (DataUnit Processing language) is a special-purpose, interpreted and functional programming language.
The DUP language looks like a mixture of C and ASN.1.
This makes it intuitive for a programmer used to C/C++ and ASN.1 to use the language.
It is possible to add CONST to the type which implies that the return value is constant and can not be changed.
All return values and arguments are passed as reference.