Path: utzoo!dciem!nrcaer!sce!ulysses!garym
From: garym@ulysses.UUCP (Gary Murphy)
Newsgroups: comp.lang.prolog
Subject: Re: Turbo Prolog (was Re: logic programs -> procedural lang?)
Keywords: Prolog, typing, compiler efficiency
Message-ID: <7169@ulysses.UUCP>
Date: 2 Oct 89 12:30:40 GMT
References: <27335@shemp.CS.UCLA.EDU> <869@gamera.cs.utexas.edu> <10822@eerie.acsu.Buffalo.EDU> <2181@munnari.oz.au> <1989Sep29.144838.16225@jarvis.csri.toronto.edu> <880@gamera.cs.utexas.edu>
Reply-To: garym@cognos.UUCP (Gary Murphy)
Organization: Cognos Inc., Ottawa, Canada
Lines: 31

In article <880@gamera.cs.utexas.edu> bradley@cs.utexas.edu (Bradley L. Richards) writes:
>
>The primary problem (from my view) is that programs cannot assert and
>retract program clauses.  The typing can be a problem if you aren't used
>to it, but in the end is probably a good feature.  But without the ability
>for a program to change its universe, a whole class of logic programs goes
>out the window.
>

TurboProlog also does not allow passing a predicate call as an argument,
removing yet another large class of applications.  Although there are
internal predicates which accept predicate arguments (such as 'trap')
there is no provision in the compiler to write new prdicates which do
the same.  In many ways, it's not Prolog, but then in many ways it's
not a serious compiler at all.

Other 'problems' are not so serious, such as the heavy reliance on .SYM
files, which require that a module compiled within a project be defined
as part of that project; to re-use a module, the source must be
recompiled with the new project's name.  On the other hand, there are
many positive sides, such as a builtin lexical scanner, a complete array
of Borland window, editor and graphics operations and some fancy tricks
at jump optimization within single-segment modules.  As a prototyping
tool for PC based applications, or as a delivery vehicle for Turbo C
I found it unsurpassed, but as a vehicle for logic programming, there
are just too many shortcomings.
-- 
     Gary Murphy - Cognos Incorporated - (613) 738-1338 x5537    
  3755 Riverside Dr - P.O. Box 9707 - Ottawa Ont - CANADA K1G 3N3
          e-mail: decvax!utzoo!dciem!nrcaer!cognos!garym         
  Cosmic Irreversibility: 1 pot T -> 1 pot P, 1 pot P /-> 1 pot T