Delegation is inheritance

Abstract

Inheritance and delegation are alternate methods for incremental definition and sharmg. It has commonly been believed that delegation provides a more powerful model. This paper demonstrates that there is a "natural" model of inheritance which captures all of the properties of delegation.Independently, certain constramts on the ability of delegation to capture inheritance are demonstrated. Finally, a new framework which fully captures both delegation and inheritance is outlined, and some of the ramifications of this hybrid model are explored.

Feature‐oriented programming: A new way of object composition

“…This explains the relations with known techniques and also compares both techniques. In fact, we will show two cases where aggregation is more expressive than inheritance, refining earlier results [7].…”

“…Hence this also serves to compare the feature model with both of these approaches and will highlight two cases where both differ. The equivalence of the two translations is easy to see and similar to the formal comparison of delegation (or aggregation) and inheritance, presented in [7].…”

Grace's Inheritance.

“…Since Lieberman and Stein's work of the mid-1980s [Lie86,Ste87], delegation has been seen as, more-or-less, an object-based version of inheritance [LSU87]. In delegation, one or more of the fields of an object r can refer to a delegate object; these fields are often called "parent" fields, following Self [CUCH91].…”

Introduction to Object-Oriented Programming

“…Prototyping {delegation) [Lieb86,Stei87,SLU89,Wegn87] is probably the most notable variation on OOP. With inheritance, an object is defined by its class.…”