Path: utzoo!attcan!uunet!aplcen!uakari.primate.wisc.edu!zaphod.mps.ohio-state.edu!usc!apple!snorkelwacker!bloom-beacon!eru!luth!sunic!ericom!eua.ericsson.se!euakan From: euakan@eua.ericsson.se (Theo.Kanter) Newsgroups: comp.lang.prolog Subject: OOP vs Logic Programming II Keywords: OOP, Logic Programming, Prolog Message-ID: <1990Jun29.123957.16727@eua.ericsson.se> Date: 29 Jun 90 12:39:57 GMT Sender: news@eua.ericsson.se Distribution: comp.lang.prolog Organization: Ellemtel Telecom Systems Labs, Stockholm, Sweden Lines: 123 THANKS! My humble question on how logic programming and object oriented programming styles could be combined turned out to be stated vaguely enough to be answered in many ways. Certainly I have my own opinion, but there are always others who know other things than you do, and therefore I thank you for being so kind to share your knowledge. STANDPOINT. At this stage I am more interested in how parts of a system prototype can be modelled on the language in question. That is not to say that I do not care about any theoretical discussions, about whether OOP and LP mix at all and it what ways. PRAGMATICS. It seems that one can get far by employing the same strategy of a message-passing style for Prolog as Abelson and Sussman did in the book "Structure and Interpretation of Computer Programs". Jonas Nygren (below) showed how one can add syntactic sugar to Prolog and implement inheritance. Mark Plotnick (below) mentions a company which has taken this farther an sells a *product* built on top of Quintus. One step farther and your over the edge into another language, which does not make things better, but in my opinion, merely changes the view or performance. THEORY? Ulrich N. (below) reminded me of one aspect of the OO paradigm. Namely, that objects have states. Now, neither mathematical logic or lambda calculus on which we try to base pure logical and functional languages provide for something called states. It seems to me that something is missing here, and that concurrency as in GHC and the like has little to do with it. LETTERS. Last but not least I have enclosed a list of references out of personal letters: Once again, thank you for your effort. --Theo ----------------------------------------------------------------------- Theo Kanter ELLEMTEL Telecommunication Systems Laboratories Box 1505, S-125 25 [lvsj| (AElvsjoe), Sweden Office: +46 8 727 35 93 Fax : +46 8 647 82 76 Telex : 12452 EUA S Mail : Theo.Kanter@eua.ericsson.se -------------------------- LETTERS -------------------------------------- -------------------------- LETTERS -------------------------------------- -------------------------- LETTERS -------------------------------------- From: norvell@csri.toronto.edu Organization: CSRI, University of Toronto ----------------------------------------- >Take a look at Ait-Kacii's language called Login. It is described >in a MCC technical report and is about prolog extended with Inhertance. >In a similar vein, but more complex is David Maier's O-logic. From: novick@ogicse.ogc.edu (David G. Novick) Organization: Oregon Graduate Institute (formerly OGC), Beaverton, OR --------------------------------------------------------------------- > P. Albert (1985). Prolog et les objets. Proceedings of the > Fifth International Workshop on Expert Systems and their Application, > Avignon, pp. 331-350. > J. Conery (1988). HOOPS manual. Technical report, University of > Oregon. From: mark@infolog.se (Mark Plotnick) Organization: Infologics AB, Box 91, 191 22 Sollentuna, Sweden. --------------------------------------------------------------- Mark wrote that he knew about 2 commercial alternatives: > Prolog++ from LPA > LAP built on top of Quintus by a french company ELSA From: yoshida@icot.or.jp (Yoshida Kaoru) ---------------------------------------- Commented Nils Hagner's respons to my article in the newsgroup, being the designer of A'UM. From: Inst.f.Prakt.Info 1802 (Ulbricht Neumerkel) Organization: Technical University of Vienna, EDP-Center -------------------------------------------------------- Wrote an interesting and lengthy letter. It's essence could be said to be that OOP does not mix well with declarative programming. I am probably doing him injustice, whatever I write.. From: jonas@falcon.ericsson.se (Jonas Nygren) Organization: Ericsson Telecom, Stockholm, Sweden ------------------------------------------------- Sent me a: > Sample POOPS class library: list{stack,queue,tree{binarytree{x}}} > In the spirit of same libraries described in > Object-Oriented Software Constuction, B Meyer, Prentice-Hall Which essentially is syntactic sugar on top of Prolog, Jonas wrote. From: ingvar@sics.se (Ingvar Olsson) Organization: Swedish Institute for Computer Science, Kista, Stockholm ---------------------------------------------------------------------- Wrote that his approach in his current project was a pragmatic one, and that he implemented a prototype using a message passing style of programming. Sounds like it resembles my own strategy. I will continue the discussions with Ingvar.