Abstract: "The purpose of this paper is to make a contribution towards the integration of Object-Orientation and logic programming. We introduce the notion of differential programs, logic programs annotated to make their external interfaces explicit. Similarly to classes in the O-O paradigm, di...

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Format:	Buch
Sprache:	English
Veröffentlicht:	Amsterdam 1993
Schriftenreihe:	Centrum voor Wiskunde en Informatica <Amsterdam> / Department of Computer Science: Report CS 93,63
Schlagworte:	Logic programming Object-oriented programming (Computer science)
Zusammenfassung:	Abstract: "The purpose of this paper is to make a contribution towards the integration of Object-Orientation and logic programming. We introduce the notion of differential programs, logic programs annotated to make their external interfaces explicit. Similarly to classes in the O-O paradigm, differential programs can be organized in isa hierarchies. The isa-composition of differential programs captures the semantics of several mechanisms such as static and dynamic overriding inheritance as well as a form of extension inheritance defined in term of composition by union of clauses. The application of the programming discipline we propose is illustrated on a concrete programming example We give a proof-theoretic semantics for isa-hierarchies: we define an inference system which extends SLD resolution to take into account the inheritance mechanisms encompassed by the isa operator. Then we introduce a corresponding operator which provides a syntactic counterpart of the isa-composition. The new operator, denoted by [symbol], transforms any isa hierarchy HP into an equivalent 'flat' program HP[subscript [symbol]] whose proof theoretic semantics is defined in terms of the standard notion of SLD derivation. Finally we define a fixed point semantics which is [symbol]-compositional and which models correctly the answer substitutions of programs By virtue of the aforesaid correspondence between isa-hierarchies and [symbol]-composite programs, we obtain a compositional semantics for isa hierarchies. The semantics of differential programs generalizes previous work on OR-compositional semantics for logic programs. It is obtained by resorting to the notion of context-sensitive interpretations, an extension of the [omega]-denotations of [3] defined as sets of non- ground clauses.
Beschreibung:	49 S.