/* Fact Utils */
/// <summary>
/// Populates the Variable predicates of a target Atom, using another Atom as a template
/// and a Fact as the source of data, i.e. Individual predicates.
/// </summary>
/// <param name="data">The data for populating the Atom.</param>
/// <param name="template">The template of Atom being populated.</param>
/// <param name="members">The members to populate.</param>
internal static void Populate(Fact data, Atom template, IPredicate[] members)
{
for(int i=0;i<members.Length;i++)
if (members[i] is Variable) {
// try to locate a Variable with the same name in the template
int j = Array.IndexOf(template.Members, members[i]);
if (j >= 0) {
members[i] = data.Members[j];
}
else {
// try to locate a Slot with the same name in the template
j = Array.IndexOf(template.SlotNames, members[i].Value);
if (j >= 0) members[i] = data.Members[j];
}
}
}
/// <summary>
/// Retracts (removes) a Fact from the current working memory.
/// </summary>
/// <param name="fact">The Fact to retract.</param>
public void Retract(Fact fact)
{
IE.Retract(fact);
}
/// <summary>
/// Modify a Fact by Retracting it and Asserting the replacement one.
/// If the new Fact has no label (null or Empty), then the Label of the existing fact is kept.
/// </summary>
/// <param name="currentFactLabel">The label of the Fact to modify.</param>
/// <param name="newFact">The Fact to modify to.</param>
/// <returns>True if <term>currentFact</term> has been retracted from the FactBase, otherwise False ; this whether <term>newFact</term> already exists in the factbase, or not.</returns>
public bool Modify(string currentFactLabel, Fact newFact)
{
return IE.Modify(currentFactLabel, newFact);
}
/// <summary>
/// Returns true if a Fact exists in the current working memory.
/// </summary>
/// <param name="fact">The Fact to check existence.</param>
/// <returns>True if the Fact exists.</returns>
public bool FactExists(Fact fact)
{
return IE.FactExists(fact);
}
protected override void WriteFact(XmlElement target, Fact fact)
{
XmlElement eFact = Document.CreateElement("fact", DatalogNamespaceURL);
WriteLabel(eFact, fact.Label);
XmlElement head = Document.CreateElement("_head", DatalogNamespaceURL);
WriteAtom(head, fact, true);
eFact.AppendChild(head);
target.AppendChild(eFact);
}
public virtual void SimilarNafMatching()
{
// regression test for bug 1332214
ie.LoadRuleBase(NewTestAdapter());
Assert.IsTrue(ie.Assert(new Fact("naf-probe",
new Individual(123),
new Individual("bar"))), "Asserted naf-probe");
Assert.IsTrue(ie.Assert(new Fact("naf-switch",
new Individual(123),
new Individual("pivot"),
new Individual("baz"))), "Asserted first naf-switch");
Fact switchToKill = new Fact("naf-switch",
new Individual(123),
new Individual("pivot"),
new Individual("foo"));
Assert.IsTrue(ie.Assert(switchToKill), "Asserted second naf-switch");
Process();
Assert.AreEqual(0, deducted, "Deducted");
Assert.IsTrue(ie.Retract(switchToKill));
Process();
Assert.AreEqual(1, deducted, "Deducted");
}
public void MutexSupport()
{
ie.LoadRuleBase(NewTestAdapter());
Fact locker = new Fact("locker", "flag", new Individual("lock"), new Individual("mutexLock"));
ie.Assert(locker);
ie.Assert(new Fact("flag", new Individual("probe"), new Individual("triggeredA")));
ie.Assert(new Fact("flag", new Individual("probe"), new Individual("triggeredB")));
Process();
Assert.AreEqual(1, deducted, "(1) Deducted");
// no garantee if A or B is deducted because they implications have same priority level
ie.Retract(locker);
Process();
Assert.AreEqual(1, deducted, "(2) Deducted");
// C should be deducted
ie.Assert(new Fact("flag", new Individual("probe"), new Individual("triggeredC")));
deductionsToCheck = new string[] {"mutexC{probe}"};
NewFactEvent honf = new NewFactEvent(HandleOrderedNewFact);
ie.NewFactHandler += honf;
Process();
Assert.AreEqual(1, deducted, "(3) Deducted");
Assert.IsFalse(wrongDeduction, "Deductions OK");
ie.NewFactHandler -= honf;
deductionsToCheck = null;
// nothing must be rededucted as
Process();
Assert.AreEqual(0, deducted, "(3) Deducted");
}
public void FactExistence()
{
ie.LoadRuleBase(NewTestAdapter());
Assert.IsTrue(ie.FactExists("Porsche Luxury"), "Existing fact label");
Assert.IsFalse(ie.FactExists("Porsche Regular"), "Non-existing fact label");
Fact factHondaRegular = new Fact("regular", new Individual("Honda"));
Fact factHondaLuxury = new Fact("luxury", new Individual("Honda"));
Assert.IsTrue(ie.FactExists(factHondaRegular), "Existing fact");
Assert.IsFalse(ie.FactExists(factHondaLuxury), "Non-existing fact");
}
private void CommonDiscountVisio2003(IRuleBaseAdapter rba)
{
ie.LoadRuleBase(rba);
Process();
Assert.AreEqual(3, deducted, "(1) Deducted");
Assert.AreEqual(6, ie.FactsCount, "(2) Total Facts Count");
deductionsToCheck = new string[] {"Discount{Peter Miller,Honda,5.0}",
"Discount{Peter Miller,Porsche,7.5}"};
qrs = ie.RunQuery(new Query(new AtomGroup(AtomGroup.LogicalOperator.And,
new Atom("Discount", new Variable("customer"),
new Variable("product"),
new Variable("amount")))));
Assert.AreEqual(2, qrs.Count, "(1) Query Result Size");
ParseResult();
Assert.IsFalse(wrongDeduction, "(1) Query Results");
// Spending JQDoe
Assert.IsTrue(ie.Assert(new Fact("Spending",
new Individual("John Q. Doe"),
new Individual(2004),
new Individual(123.45f))),
"jqdoeSpending asserted");
Fact jqdoePremiumRating = new Fact("Customer Rating",
new Individual("John Q. Doe"),
new Individual("Premium"));
Assert.IsTrue(ie.Assert(jqdoePremiumRating), "jqdoePremiumRating asserted");
// SpendingJDupont
Assert.IsTrue(ie.Assert(new Fact("Spending",
new Individual("Jean Dupont"),
new Individual(2004),
new Individual(3245.25f))),
"jdupontSpending asserted");
Process();
Assert.IsFalse(ie.FactExists(jqdoePremiumRating), "jqdoePremiumRating was retracted");
Assert.AreEqual(4, deducted, "(2) Deducted");
Assert.AreEqual(12, ie.FactsCount, "(2) Total Facts Count");
// Run named queries
deductionsToCheck = new string[] {"Discount{Peter Miller,Honda,5.0}",
"Discount{Peter Miller,Porsche,7.5}",
"Discount{Jean Dupont,Honda,5.0}",
"Discount{Jean Dupont,Porsche,7.5}"};
qrs = ie.RunQuery("Calculated Discounts");
Assert.AreEqual(4, qrs.Count, "(2) Query Result Size");
ParseResult();
Assert.IsFalse(wrongDeduction, "(2) Query Results");
deductionsToCheck = new string[] {"Customer Rating{Peter Miller,Premium}",
"Customer Rating{John Q. Doe,Regular}",
"Customer Rating{Jean Dupont,Premium}"};
qrs = ie.RunQuery("Customer Ratings");
Assert.AreEqual(3, qrs.Count, "(3) Query Result Size");
ParseResult();
Assert.IsFalse(wrongDeduction, "(3) Query Results");
}
public void Discount()
{
ie.LoadRuleBase(new RuleML08DatalogAdapter(ruleFilesFolder + "discount.ruleml", FileAccess.Read));
Process();
Assert.AreEqual(3, deducted, "(1) Deducted");
Assert.AreEqual(6, ie.FactsCount, "(1) Total Facts Count");
deductionsToCheck = new string[] {"discount{Peter Miller,Honda,5.0 percent}",
"discount{Peter Miller,Porsche,7.5 percent}"};
qrs = ie.RunQuery(new Query(new AtomGroup(AtomGroup.LogicalOperator.And,
new Atom("discount", new Variable("customer"),
new Variable("product"),
new Variable("amount")))));
Assert.AreEqual(2, qrs.Count, "(1) Query Result Size");
ParseResult();
Assert.IsFalse(wrongDeduction, "(1) Query Results");
// Fact 4 - this is a bummer
Fact fact4 = new Fact("bummer",
"spending",
new Individual("John Q. Doe"),
new Individual("min 5000 euro"),
new Individual("previous year"),
new Individual("current year"));
ie.Assert(fact4);
// Fact 5
ie.Assert(new Fact("spending",
new Individual("Jean Dupont"),
new Individual("min 5000 euro"),
new Individual("previous year")));
Process();
Assert.AreEqual(3, deducted, "(2) Deducted");
Assert.AreEqual(11, ie.FactsCount, "(2) Total Facts Count");
// Run anonymous (not named) query
deductionsToCheck = new string[] {"discount{Peter Miller,Honda,5.0 percent}",
"discount{Peter Miller,Porsche,7.5 percent}",
"discount{Jean Dupont,Honda,5.0 percent}",
"discount{Jean Dupont,Porsche,7.5 percent}"};
qrs = ie.RunQuery(0);
Assert.AreEqual(4, qrs.Count, "(2) Query Result Size");
ParseResult();
Assert.IsFalse(wrongDeduction, "(2) Query Results");
}
protected abstract void WriteFact(XmlElement target, Fact fact);
/// <summary>
/// Instantiates a new Fact event definition.
/// </summary>
/// <remarks>
/// DO NOT ASSERT OR RETRACT FACTS WHEN HANDLING THIS EVENT!
/// </remarks>
/// <param name="fact">The Fact that generated the event.</param>
/// <param name="otherFact">The Other Fact that generated the event.</param>
/// <param name="context">The context of the event.</param>
public NewFactEventArgs(Fact fact, Fact otherFact, IEventContext context)
{
this.fact = fact;
this.otherFact = otherFact;
this.context = context;
}
/// <summary>
/// Instantiates a new Fact event definition.
/// </summary>
/// <remarks>
/// DO NOT ASSERT OR RETRACT FACTS WHEN HANDLING THIS EVENT!
/// </remarks>
/// <param name="fact">The Fact that generated the event.</param>
/// <param name="otherFact">The Other Fact that generated the event.</param>
public NewFactEventArgs(Fact fact, Fact otherFact)
: this(fact, otherFact, null)
{
}
/// <summary>
/// Instantiates a new Fact event definition.
/// </summary>
/// <remarks>
/// DO NOT ASSERT OR RETRACT FACTS WHEN HANDLING THIS EVENT!
/// </remarks>
/// <param name="fact">The Fact that generated the event.</param>
/// <param name="context">The context of the event.</param>
public NewFactEventArgs(Fact fact, IEventContext context)
: this(fact, null, context)
{
}
/// <summary>
/// Instantiates a new Fact event definition.
/// </summary>
/// <remarks>
/// DO NOT ASSERT OR RETRACT FACTS WHEN HANDLING THIS EVENT!
/// </remarks>
/// <param name="fact">The Fact that generated the event.</param>
public NewFactEventArgs(Fact fact)
: this(fact, null, null)
{
}
private Fact(Fact source, IPredicate[] members) : base(source, members)
{
this.label = source.label;
}
/// <summary>
/// Retracts (removes) a Fact from the current working memory.
/// </summary>
/// <param name="fact">The Fact to retract.</param>
/// <returns>True if the Fact has been retracted from the FactBase, otherwise False.</returns>
public bool Retract(Fact fact)
{
CheckInitialized();
return WM.FB.Retract(fact);
}
/// <summary>
/// Prepare the atom to be pattern matched by replacing in a fact:
/// - all the predicates that match function predicates in the passed atom with
/// the string representation of these function predicates,
/// - all the predicates that match individual predicates in the passed atom with
/// the string representation of these individual predicates.
/// </summary>
/// <remarks>
/// This operation must be done *if and only if* the fact matches the atom.
/// </remarks>
/// <param name="factToResolve">The fact that must be resolved.</param>
/// <param name="atom">The atom with which the current fact matches.</param>
/// <returns>A new fact with only String individuals.</returns>
internal static Fact Resolve(Fact factToResolve, Atom atom)
{
return Resolve(true, factToResolve, atom);
}
public void ImplicationModifySupport()
{
ie.LoadRuleBase(NewTestAdapter());
Assert.IsTrue(ie.Assert(new Fact("modifyTrigger",
new Individual("foo"),
new Individual("bar"))), "Asserted trigger fact");
ie.NewWorkingMemory(WorkingMemoryTypes.Isolated);
Process();
Assert.AreEqual(0, deducted, "(1) Deducted");
deductionsToCheck = new string[] {"modifyTarget{bar,after}"};
// test with non labeled fact
ie.NewWorkingMemory(WorkingMemoryTypes.Isolated);
Fact toModify = new Fact("modifyTarget",
new Individual("bar"),
new Individual("before"));
Assert.IsFalse(ie.FactExists(toModify), "(2) Target fact not present");
Assert.IsTrue(ie.Assert(toModify), "(2) Asserted target fact");
Assert.IsTrue(ie.FactExists(toModify), "(2) Target fact present");
int initialFactsCount = ie.FactsCount;
Process();
Assert.AreEqual(initialFactsCount, ie.FactsCount, "(2) Stable FactsCount");
Assert.AreEqual(0, deducted, "(2) Deducted");
Assert.AreEqual(0, deleted, "(2) Deleted");
Assert.AreEqual(1, modified, "(2) Modified");
Assert.IsFalse(ie.FactExists(toModify), "(2) Target fact retracted");
// test with labeled fact
ie.NewWorkingMemory(WorkingMemoryTypes.Isolated);
string label = "label of modifyTarget";
toModify = new Fact(label,
"modifyTarget",
new Individual("bar"),
new Individual("before"));
Assert.IsFalse(ie.FactExists(toModify), "(3) Target fact not present");
Assert.IsFalse(ie.FactExists(label), "(3) Target fact label not present");
Assert.IsTrue(ie.Assert(toModify), "(3) Asserted target fact");
Assert.IsTrue(ie.FactExists(toModify), "(3) Target fact present");
Assert.IsTrue(ie.FactExists(label), "(3) Target fact label present");
initialFactsCount = ie.FactsCount;
Process();
Assert.AreEqual(initialFactsCount, ie.FactsCount, "(3) Stable FactsCount");
Assert.AreEqual(0, deducted, "(3) Deducted");
Assert.AreEqual(0, deleted, "(3) Deleted");
Assert.AreEqual(1, modified, "(3) Modified");
Assert.IsFalse(ie.FactExists(toModify), "(3) Target fact retracted");
Assert.IsTrue(ie.FactExists(label), "(3) Target fact label present");
}
/// <summary>
/// Prepare the atom to be pattern matched by replacing in a fact:
/// - all the predicates that match function predicates in the passed atom with
/// the string representation of these function predicates,
/// - in fully mode, all the predicates that match individual predicates in the passed atom with
/// the string representation of these individual predicates.
/// </summary>
/// <remarks>
/// This operation must be done *if and only if* the fact matches the atom.
/// </remarks>
/// <param name="fully">Forces resolution of non-string individual to String.</param>
/// <param name="factToResolve">The fact that must be resolved.</param>
/// <param name="atom">The atom with which the current fact matches.</param>
/// <returns>A new fact with only String individuals.</returns>
internal static Fact Resolve(bool fully, Fact factToResolve, Atom atom)
{
IPredicate[] predicates = new IPredicate[factToResolve.Members.Length];
for(int i=0; i<factToResolve.Members.Length; i++) {
if ((atom.Members[i] is Function)
|| ((fully) && (atom.Members[i] is Individual) && (!(factToResolve.Members[i].Value is System.String)))) {
predicates[i] = new Individual(atom.Members[i].ToString());
}
else {
predicates[i] = factToResolve.Members[i];
}
}
return (Fact)factToResolve.CloneWithNewMembers(predicates);
}
public void RetractingImplication()
{
ie.LoadRuleBase(NewTestAdapter());
Fact factToRetract = new Fact("toRetract", new Individual("easy target"));
Assert.IsFalse(ie.FactExists(factToRetract), "1st Pre-check before target assertion");
ie.Assert(factToRetract);
Assert.IsTrue(ie.FactExists(factToRetract), "2nd Pre-check before target assertion");
// this process should leave the target unchanged
Process();
Assert.IsTrue(ie.FactExists(factToRetract), "1st process: fact unchanged");
Assert.AreEqual(0, deleted, "1st process: deleted");
Assert.AreEqual(0, deducted, "1st process: deleted");
// after asserting the trigger, process should retract the target
Fact factRetractionTrigger = new Fact("retractionTrigger", new Individual("easy target"));
Fact factRetractionConfirmation = new Fact("retractionConfirmation", new Individual("easy target"));
ie.Assert(factRetractionTrigger);
Process();
Assert.IsFalse(ie.FactExists(factToRetract), "2nd process: fact retracted");
Assert.IsTrue(ie.FactExists(factRetractionConfirmation), "2nd process: retracting implication positive pre-conditionned");
Assert.AreEqual(1, deleted, "2nd process: deleted");
Assert.AreEqual(1, deducted, "2nd process: deducted");
}
private int RunImplication(Implication implication)
{
int implicationResultsCount = 0;
IList<IList<FactBase.PositiveMatchResult>> processResults = WM.FB.ProcessAtomGroup(implication.AtomGroup);
if (implication.Action == ImplicationAction.Count)
{
if (Logger.IsInferenceEngineVerbose) Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, "Counting Implication '" + implication.Label + "' counted: " + processResults.Count);
bool variableFound = false;
IPredicate[] members = (IPredicate[])implication.Deduction.Members.Clone();
for(int i=0; !variableFound && i<members.Length; i++) {
if (members[i] is Variable) {
members[i] = new Individual(processResults.Count);
variableFound = true;
break;
}
}
if ((strictImplication) && (!variableFound))
throw new BREException("Strict counting implication rejected the assertion due to lack of variable predicate: " + implication.Deduction);
Fact deductedFact = new Fact(implication.Deduction.Type, members);
implicationResultsCount++;
// counting implication factbase action
bool result = WM.FB.Assert(deductedFact);
if ((result) && (NewFactHandler != null)) {
if (exposeEventContext) {
NewFactHandler(new NewFactEventArgs(deductedFact,
EventContextFactory.NewEventContext(processResults, implication)));
} else {
NewFactHandler(new NewFactEventArgs(deductedFact));
}
}
if (Logger.IsInferenceEngineVerbose) {
Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, (result?"Asserted":"Ignored Assertion of ") + " Fact: " + deductedFact.ToString());
}
}
else if ((implication.Action == ImplicationAction.Assert)
|| (implication.Action == ImplicationAction.Retract))
{
// loop on each result and try to build a new fact out of the predicates coming for each result
foreach(IList<FactBase.PositiveMatchResult> processResult in processResults) {
Fact deductedFact = BuildFact(implication.Deduction, processResult);
if (deductedFact != null) {
implicationResultsCount++;
if (implication.Action == ImplicationAction.Retract) {
// retracting implication factbase action
bool result = WM.FB.Retract(deductedFact);
if ((result) && (DeleteFactHandler != null)) {
if (exposeEventContext) {
DeleteFactHandler(new NewFactEventArgs(deductedFact,
EventContextFactory.NewEventContext(processResult, implication)));
} else {
DeleteFactHandler(new NewFactEventArgs(deductedFact));
}
}
if (Logger.IsInferenceEngineVerbose) {
Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, (result?"Retracted":"Ignored Retraction of ") + " Fact: " + deductedFact.ToString());
}
}
else {
// asserting implication factbase action
bool result = WM.FB.Assert(deductedFact);
if ((result) && (NewFactHandler != null)) {
if (exposeEventContext) {
NewFactHandler(new NewFactEventArgs(deductedFact,
EventContextFactory.NewEventContext(processResult, implication)));
} else {
NewFactHandler(new NewFactEventArgs(deductedFact));
}
}
if (Logger.IsInferenceEngineVerbose) {
Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, (result?"Asserted":"Ignored Assertion of ") + " Fact: " + deductedFact.ToString());
}
}
}
}
}
else if (implication.Action == ImplicationAction.Modify)
{
foreach(IList<FactBase.PositiveMatchResult> processResult in processResults) {
// look for facts to modify by:
// - resolving variable predicates of the deduction
// - replacing formulas with variables
// and performing a search in the fact base
Atom modificationTargetLookup = FactBase.BuildQueryFromDeduction(implication.Deduction, processResult);
if (Logger.IsInferenceEngineVerbose) Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, "Modifying Implication '" + implication.Label + "' will target matches of: " + modificationTargetLookup);
foreach(Fact factToModify in FactBase.ExtractAllFacts(WM.FB.ProcessAtomGroup(new AtomGroup(AtomGroup.LogicalOperator.And, modificationTargetLookup)))) {
if (Logger.IsInferenceEngineVerbose) Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, "-> found target: " + factToModify);
// for each fact, perform the modification
Fact deductedFact = BuildFact(implication.Deduction,
FactBase.EnrichResults(processResult, modificationTargetLookup, factToModify));
if (Logger.IsInferenceEngineVerbose) Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, "-> modified target: " + deductedFact);
if ((deductedFact != null) && (!factToModify.Equals(deductedFact))) {
implicationResultsCount++;
bool result = WM.FB.Modify(factToModify, deductedFact);
if ((result) && (ModifyFactHandler != null)) {
if (exposeEventContext) {
ModifyFactHandler(new NewFactEventArgs(factToModify,
deductedFact,
EventContextFactory.NewEventContext(processResult, implication)));
} else {
ModifyFactHandler(new NewFactEventArgs(factToModify, deductedFact));
}
}
if (Logger.IsInferenceEngineVerbose) {
Logger.InferenceEngineSource.TraceEvent(TraceEventType.Verbose, 0, (result?"Modified":"Ignored Modification of ") + " Fact: " + factToModify.ToString());
}
}
}
}
}
else {
throw new BREException("Implication action not supported: " + implication.Action);
}
return implicationResultsCount;
}
private Fact(Fact source, IPredicate[] members)
: base(source, members)
{
this.label = source.label;
}
/// <summary>
/// Asserts (adds) a Fact in the current working memory.
/// </summary>
/// <param name="fact">The Fact to assert.</param>
/// <returns>True if the Fact was added to the Fact Base, i.e. if it was really new!</returns>
public bool Assert(Fact fact)
{
CheckInitialized();
return WM.FB.Assert(fact);
}
protected override void WriteFact(XmlElement target, Fact fact)
{
if (syntax == SaveFormatAttributes.Expanded) {
XmlElement formula = Document.CreateElement("formula", DatalogNamespaceURL);
WriteAtom(formula, fact, true);
target.AppendChild(formula);
}
else {
WriteAtom(target, fact, true);
}
}
/// <summary>
/// Returns true if a Fact exists in the current working memory.
/// </summary>
/// <param name="fact">The Fact to check existence.</param>
/// <returns>True if the Fact exists.</returns>
public bool FactExists(Fact fact)
{
CheckInitialized();
return WM.FB.Exists(fact);
}
/// <summary>
/// Modify a Fact by Retracting it and Asserting the replacement one.
/// If the new Fact has no label (null or Empty), then the Label of the existing fact is kept.
/// </summary>
/// <param name="currentFact">The Fact to modify.</param>
/// <param name="newFact">The Fact to modify to.</param>
/// <returns>True if <term>currentFact</term> has been retracted from the FactBase, otherwise False ; this whether <term>newFact</term> already exists in the factbase, or not.</returns>
public bool Modify(Fact currentFact, Fact newFact)
{
return IE.Modify(currentFact, newFact);
}
/// <summary>
/// Modify a Fact by Retracting it and Asserting the replacement one.
/// If the new Fact has no label (null or Empty), then the Label of the existing fact is kept.
/// </summary>
/// <param name="currentFact">The Fact to modify.</param>
/// <param name="newFact">The Fact to modify to.</param>
/// <returns>True if <term>currentFact</term> has been retracted from the FactBase, otherwise False ; this whether <term>newFact</term> already exists in the factbase, or not.</returns>
public bool Modify(Fact currentFact, Fact newFact)
{
CheckInitialized();
return WM.FB.Modify(currentFact, newFact);
}
/// <summary>
/// Creates a new Fact.
/// </summary>
/// <remarks>
/// This method is an helper of the regular Fact instantiation.
/// </remarks>
/// <param name="type">The Type of the new Fact to assert.</param>
/// <param name="individuals">The Individual predicatesthat the Fact will contain.</param>
/// <returns>A new Fact of desired Type and individuals.</returns>
public Fact NewFact(string type, params object[] individuals)
{
Fact newFact;
if (individuals.Length == 0) {
newFact = new Fact(type);
}
else if (individuals.Length == 1) {
newFact = new Fact(type, new Individual(individuals[0]));
}
else {
Individual[] members = new Individual[individuals.Length];
for (int i=0; i<individuals.Length; i++) members[i] = new Individual(individuals[i]);
newFact = new Fact(type, members);
}
return newFact;
}
/// <summary>
/// Modify a Fact by Retracting it and Asserting the replacement one.
/// If the new Fact has no label (null or Empty), then the Label of the existing fact is kept.
/// </summary>
/// <param name="currentFactLabel">The label of the Fact to modify.</param>
/// <param name="newFact">The Fact to modify to.</param>
/// <returns>True if <term>currentFact</term> has been retracted from the FactBase, otherwise False ; this whether <term>newFact</term> already exists in the factbase, or not.</returns>
public bool Modify(string currentFactLabel, Fact newFact)
{
Fact currentFact = GetFact(currentFactLabel);
if (currentFact != null) {
return WM.FB.Modify(currentFact, newFact);
}
else {
return false;
}
}
/// <summary>
/// Asserts (adds) a Fact in the current working memory.
/// </summary>
/// <param name="fact">The Fact to assert.</param>
/// <returns>True if the Fact was added to the Fact Base, i.e. if it was really new!</returns>
public bool Assert(Fact fact)
{
return IE.Assert(fact);
}
private Fact(Fact source, IPredicate[] members) : base(source.Label, source, members)
{
}