Safe Dynamic Multiple Inheritance

Combination of descriptive entities—i.e. multiple inheritance and related mechanisms—is usually only supported at compile time in statically typed languages. The language gbeta is statically typed and has supported run-time creation of classes and methods since 1997, by means of the pattern combination operator ‘&’. However, with certain combinations of operands the ‘&’ operator fails; as a result, creation of new classes and methods at run-time had to be considered a dangerous operation. This paper presents a large and useful class of combinations, and proves that combinations in this class will always succeed.