Mixin-based inheritance (OOPSLA '90)

[kavon]

https://dl.acm.org/citation.cfm?id=97982

The diverse inheritance mechanisms provided by Smalltalk, Beta, and CLOS are interpreted as different uses of a single underlying construct. Smalltalk and Beta differ primarily in the direction of class hierarchy growth. These inheritance mechanisms are subsumed in a new inheritance model based on composition of mixins, or abstract subclasses. This form of inheritance can also encode a CLOS multiple-inheritance hierarchy, although changes to the encoded hierarchy that would violate encapsulation are difficult. Practical application of mixin-based inheritance is illustrated in a sketch of an extension to Modula-3.