Reply-To: "killian" From: "killian" Newsgroups: comp.lang.prolog References: <3b6dbf98$1@nubby2.> Subject: Re: Typed Prolog Question Lines: 65 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2615.200 X-MIMEOLE: Produced By Microsoft MimeOLE V5.00.2615.200 Message-ID: Date: Mon, 06 Aug 2001 03:18:13 GMT NNTP-Posting-Host: 209.204.154.206 X-Complaints-To: abuse@sonic.net X-Trace: typhoon.sonic.net 997067893 209.204.154.206 (Sun, 05 Aug 2001 20:18:13 PDT) NNTP-Posting-Date: Sun, 05 Aug 2001 20:18:13 PDT [rev. 17feb03 - wdbh] Doug Ransom wrote in message news:3b6dbf98$1@nubby2.... > I have been reading the Visual Prolog manual and found this : > "Unlike other versions of Prolog, Visual Prolog is a typed Prolog > compiler; you declare the types of the objects that each predicate applies to". > > I am just starting out with Prolog. Is this typing going to result in > any problems? Other things being equal, all you have to do to port a VP program to non-typed Prolog is to delete all your DOMAIN and PREDICATE declarations. The difficulty is in going the opposite direction. I dislike VP because it is proprietary, because I think they charge way too much money for a license to use the binaries, and because I consider that Windows-style user interfaces and Prolog programming are antithetical. Windows-style user interfaces make you keep your question in mind while you go hunting for the cheese that answers it. Prolog takes your question and uses it to find the answers for you. I am therefore not much interested in using Prolog to build WIndows-style user interfaces and except for trival tasks. I don't like using Windows-style user interfaces myself, so the idea that my Prolog programming environment should have a Windows-style user interface is not something I get very excited about. On the other hand, programming in a language that does not supply powerful means of preventing compile-time mistakes is impermissible in real-world applications of any consequence. I would like to see something like Gnu Prolog with the parser and the inference engine modified to accomodate the system of index definitions and predicate declarations that I proposed in these pages several years ago [Message ID ]. --