Final Data Types and Their Specification

Abstract

data type specification is a description of the properties of a data abstraction for the benefit of its users and implementers. The data abstraction has realizations, all of which behave in a certain way. It is those properties implied by this behavior which we consider essential; properties specific to some realization are extraneous. The specification problem is to present all of the essential properties and no extraneous ones. We propose a specification method based upon the notion of “final data type.” A final data type is the smallest structure having a given behavior; every other structure having that behavior maps onto it homomorphically. This property makes the final data type specification a particularly good source of information about the abstraction it realizes, and eliminates “implementation bias” from the method. © 1983, ACM. All rights reserved.