C# Variable.getValue方法代码示例

        /// <summary>
        /// Return true if there is a dynamic or static predicate with name and arity.
        /// This returns false for built-in predicates.
        /// </summary>
        /// <param name="name"></param>
        /// <param name="arity"></param>
        /// <param name="declaringClass">used to resolve references to the default 
        /// module Atom.a(""). If a declaringClass is needed to resolve the reference but it is
        ///   null, return false</param>
        /// <returns></returns>
        public static bool isCurrentPredicate(Atom name, int arity, Type declaringClass)
        {
            CompilerState state = new CompilerState();
            Variable FunctionName = new Variable();
            foreach (bool l1 in functorCallFunctionName(state, name, arity, FunctionName))
            {
                Atom functionNameAtom = ((Atom)FunctionName.getValue());
                if (functionNameAtom == Atom.NIL)
                    // name is for a dynamic predicate.
                    return YP.isDynamicCurrentPredicate(name, arity);

                string methodName = functionNameAtom._name;

                if (methodName.StartsWith("YP."))
                    // current_predicate/1 should fail for built-ins.
                    return false;
                if (methodName.Contains("."))
                    // We don't support calling inner classes, etc.
                    return false;
                if (declaringClass == null)
                    return false;

                foreach (MemberInfo member in declaringClass.GetMember(methodName))
                {
                    MethodInfo method = member as MethodInfo;
                    if (method == null)
                        continue;
                    if ((method.Attributes | MethodAttributes.Static) == 0)
                        // Not a static method.
                        continue;
                    if (method.GetParameters().Length == arity)
                        return true;
                }
            }

            return false;
        }

        // disable warning on l1, don't see how we can
        // code this differently
        #pragma warning disable 0168, 0219,0164,0162

        /// <summary>
        /// Use makeFunctionPseudoCode, convertFunctionCSharp and compileAnonymousFunction
        /// to return an anonymous YP.IClause for the Head and Body of a rule clause.
        /// </summary>
        /// <param name="Head">a prolog term such as new Functor2("test1", X, Y).
        /// Note that the name of the head is ignored.
        /// </param>
        /// <param name="Body">a prolog term such as 
        /// new Functor2(",", new Functor1(Atom.a("test2", Atom.a("")), X), 
        ///              new Functor2("=", Y, X)).
        /// This may not be null.  (For a head-only clause, set the Body to Atom.a("true").
        /// </param>
        /// <param name="declaringClass">if not null, the code is compiled as a subclass of this class
        /// to resolve references to the default module Atom.a("")</param>
        /// <returns>a new YP.IClause object on which you can call match(object[] args) where
        /// args length is the arity of the Head</returns>
        public static YP.IClause compileAnonymousClause(object Head, object Body, Type declaringClass)
        {
            object[] args = YP.getFunctorArgs(Head);
            // compileAnonymousFunction wants "function".
            object Rule = new Functor2(Atom.RULE, Functor.make("function", args), Body);
            object RuleList = ListPair.make(new Functor2(Atom.F, Rule, Atom.NIL));

            StringWriter functionCode = new StringWriter();
            Variable SaveOutputStream = new Variable();
            foreach (bool l1 in YP.current_output(SaveOutputStream))
            {
                try
                {
                    YP.tell(functionCode);
                    Variable PseudoCode = new Variable();
                    foreach (bool l2 in makeFunctionPseudoCode(RuleList, PseudoCode))
                    {
                        if (YP.termEqual(PseudoCode, Atom.a("getDeclaringClass")))
                            // Ignore getDeclaringClass since we have access to the one passed in.
                            continue;

                        convertFunctionCSharp(PseudoCode);
                    }
                    YP.told();
                }
                finally
                {
                    // Restore after calling tell.
                    YP.tell(SaveOutputStream.getValue());
                }
            }
            return YPCompiler.compileAnonymousFunction
                (functionCode.ToString(), args.Length, declaringClass);
        }

        /// <summary>
        /// If the functor with name and args can be called directly as determined by
        ///   functorCallFunctionName, then call it and return its iterator.  If the predicate is
        ///   dynamic and undefined, or if static and the method cannot be found, return
        ///   the result of YP.unknownPredicate.
        /// This returns null if the functor has a special form than needs to be compiled 
        ///   (including ,/2 and ;/2).
        /// </summary>
        /// <param name="name"></param>
        /// <param name="args"></param>
        /// <param name="declaringClass">used to resolve references to the default 
        /// module Atom.a(""). If a declaringClass is needed to resolve the reference but it is
        ///   null, this throws a PrologException for existence_error</param>
        /// <returns></returns>
        public static IEnumerable<bool> getSimpleIterator(Atom name, object[] args, Type declaringClass)
        {
            CompilerState state = new CompilerState();
            Variable FunctionName = new Variable();
            foreach (bool l1 in functorCallFunctionName(state, name, args.Length, FunctionName))
            {
                Atom functionNameAtom = ((Atom)FunctionName.getValue());
                if (functionNameAtom == Atom.NIL)
                    // name is for a dynamic predicate.
                    return YP.matchDynamic(name, args);

                string methodName = functionNameAtom._name;
                // Set the default for the method to call.
                Type methodClass = declaringClass;

                bool checkMode = false;
                if (methodName.StartsWith("YP."))
                {
                    // Assume we only check mode in calls to standard Prolog predicates in YP.
                    checkMode = true;

                    // Use the method in class YP.
                    methodName = methodName.Substring(3);
                    methodClass = typeof(YP);
                }
                if (methodName.Contains("."))
                    // We don't support calling inner classes, etc.
                    return null;

                if (methodClass == null)
                    return YP.unknownPredicate
                        (name, args.Length,
                         "Cannot find predicate function for: " + name + "/" + args.Length + 
                         " because declaringClass is null.  Set declaringClass to the class containing " +
                         methodName);
                try
                {
                    if (checkMode)
                    {
                        assertYPPred(state);
                        object functor = Functor.make(name, args);
                        if (CompilerState.isDetNoneOut(state, functor))
                        {
                            methodClass.InvokeMember
                                (methodName, BindingFlags.InvokeMethod, null, null, args);
                            return YP.succeed();
                        }
                        if (CompilerState.isSemidetNoneOut(state, functor))
                        {
                            if ((bool)methodClass.InvokeMember
                                 (methodName, BindingFlags.InvokeMethod, null, null, args))
                                return YP.succeed();
                            else
                                return YP.fail();
                        }

                    }
                    return (IEnumerable<bool>)methodClass.InvokeMember
                      (methodName, BindingFlags.InvokeMethod, null, null, args);
                }
                catch (TargetInvocationException exception)
                {
                    throw exception.InnerException;
                }
                catch (MissingMethodException)
                {
                    return YP.unknownPredicate
                        (name, args.Length,
                         "Cannot find predicate function " + methodName + " for " + name + "/" + args.Length + 
                         " in " + methodClass.FullName);
                }
            }

            return null;
        }

            public static bool isSemidetNoneOut(object State, object Term)
            {
                State = YP.getValue(State);
                object functorName = YP.getFunctorName(Term);
                object[] functorArgs = YP.getFunctorArgs(Term);

                Variable pred = new Variable();
                foreach (bool l1 in ((CompilerState)State)._pred.match
                    (new object[] { functorName, functorArgs.Length, pred, Atom.a("semidet") }))
                {
                    if (CompilerState.isNoneOut(YP.getFunctorArgs(pred.getValue())))
                    {
                        return true;
                    }
                }

                return false;
            }