Exemple #1
0
        /// <summary>
        /// Tests clauses in a randomized order (but still exhaustively).
        /// Uses Shuffler to generate a random permutation.
        /// </summary>
        IEnumerable <CutState> TestShuffledClauses(object[] args, PrologContext context, ushort myFrame)
        {
            entriesListUsed = true;
            var mark        = context.MarkTrace();
            var shuffler    = new Shuffler((ushort)Entries.Count);
            var argIndexers = PredicateArgumentIndexer.ArglistIndexers(args);

            while (!shuffler.Done)
            {
                var entry = Entries[shuffler.Next()];
                if (entry.Prematch(argIndexers))
                {
                    // This shouldn't be here...
                    //context.PushGoalStack(Name, args, myFrame);
                    context.SetCurrentRule(entry);
                    foreach (var cutState in entry.Prove(args, context, myFrame))
                    {
                        if (cutState == CutState.ForceFail)
                        {
                            if (KnowledgeBase.Trace || Trace)
                            {
                                context.TraceOutput("Cut: {0}", new Structure(Name, args));
                            }
                            goto fail;
                        }
                        if (KnowledgeBase.Trace || Trace)
                        {
                            context.TraceOutput("Succeed: {0}", new Structure(Name, args));
                        }
                        yield return(CutState.Continue);

                        if (KnowledgeBase.Trace || Trace)
                        {
                            context.TraceOutput("Retry: {0}", new Structure(Name, args));
                        }
                    }
                }
            }
fail:
            context.RestoreVariables(mark);
            if (KnowledgeBase.Trace || Trace)
            {
                context.TraceOutput("Fail: {0}", new Structure(Name, args));
            }
            //context.UnwindStack(Name, args);
            context.UnwindStack(myFrame);
        }
Exemple #2
0
        private static IEnumerable<CutState> RandomMemberImplementation(object[] args, PrologContext context)
        {
            if (args.Length != 2) throw new ArgumentCountException("random_member", args, "element", "list");
            object objectArg = Term.Deref(args[0]);
            object listArg = Term.Deref(args[1]);
            if (listArg == null)
                yield break;
            var arg = listArg as LogicVariable;
            if (arg != null)
                throw new InstantiationException(arg, "List argument to random_member/2 must be instantiated to a proper list.");
            var length = Prolog.PrologListLength(listArg);
            var shuffler = new Shuffler((ushort)length);
            while (!shuffler.Done)
#pragma warning disable 414, 168, 219
                // ReSharper disable once UnusedVariable
                foreach (var ignore in Term.Unify(objectArg, Prolog.PrologListElement(listArg, shuffler.Next())))
#pragma warning restore 414, 168, 219
                    yield return CutState.Continue;
        }
Exemple #3
0
 /// <summary>
 /// Tests clauses in a randomized order (but still exhaustively).
 /// Uses Shuffler to generate a random permutation.
 /// </summary>
 IEnumerable<CutState> TestShuffledClauses(object[] args, PrologContext context, ushort myFrame)
 {
     entriesListUsed = true;
     var mark = context.MarkTrace();
     var shuffler = new Shuffler((ushort)Entries.Count);
     var argIndexers = PredicateArgumentIndexer.ArglistIndexers(args);
     while (!shuffler.Done)
     {
         var entry = Entries[shuffler.Next()];
         if (entry.Prematch(argIndexers))
         {
             // This shouldn't be here...
             //context.PushGoalStack(Name, args, myFrame);
             context.SetCurrentRule(entry);
             foreach (var cutState in entry.Prove(args, context, myFrame))
             {
                 if (cutState == CutState.ForceFail)
                 {
                     if (KnowledgeBase.Trace || Trace)
                         context.TraceOutput("Cut: {0}", new Structure(Name, args));
                     goto fail;
                 }
                 if (KnowledgeBase.Trace || Trace)
                     context.TraceOutput("Succeed: {0}", new Structure(Name, args));
                 yield return CutState.Continue;
                 if (KnowledgeBase.Trace || Trace)
                     context.TraceOutput("Retry: {0}", new Structure(Name, args));
             }
         }
     }
     fail:
     context.RestoreVariables(mark);
     if (KnowledgeBase.Trace || Trace)
         context.TraceOutput("Fail: {0}", new Structure(Name, args));
     //context.UnwindStack(Name, args);
     context.UnwindStack(myFrame);
 }