Package apple.gameplaykit

Class GKRuleSystem

  • All Implemented Interfaces:
    NSObject
    public class GKRuleSystem
extends NSObject
    A rule system consists of 3 things: - The current state, which upon creation is considered the inital state. - The current set of rules. - The current set of facts. Each time a fact is added to the system, the set of rules are evaluated in order and their actions executed in the system if their predicates are true. Rules can be fuzzy, allowing predicates and facts to be asserted to a degree of confidence instead of just boolean on/off. The facts can be any kind of objects as long as they correctly determine equality using isEqual: The simplest approach is to use strings or dictionaries as they provide the most flexibility in defining facts, but user defined classes work just as well and may describe the problem space better. The fact set is at all times a fuzzy set, as defined by fact membership in the set being modulated by their grade of membership. The rules may use the grade of membership to predicate their actions and in such a manner create fuzzy logic. The fuzzy logic Zadeh operators are available on the system itself in order to query multiple facts for combined membership grade.

    • Constructor Detail

      • GKRuleSystem

        protected GKRuleSystem​(org.moe.natj.general.Pointer peer)

    • Method Detail

      • accessInstanceVariablesDirectly

        public static boolean accessInstanceVariablesDirectly()

      • allocWithZone

        public static java.lang.Object allocWithZone​(org.moe.natj.general.ptr.VoidPtr zone)

      • automaticallyNotifiesObserversForKey

        public static boolean automaticallyNotifiesObserversForKey​(java.lang.String key)

      • cancelPreviousPerformRequestsWithTarget

        public static void cancelPreviousPerformRequestsWithTarget​(java.lang.Object aTarget)

      • cancelPreviousPerformRequestsWithTargetSelectorObject

        public static void cancelPreviousPerformRequestsWithTargetSelectorObject​(java.lang.Object aTarget,
                                                                         org.moe.natj.objc.SEL aSelector,
                                                                         java.lang.Object anArgument)

      • classFallbacksForKeyedArchiver

        public static NSArray<java.lang.String> classFallbacksForKeyedArchiver()

      • classForKeyedUnarchiver

        public static org.moe.natj.objc.Class classForKeyedUnarchiver()

      • debugDescription_static

        public static java.lang.String debugDescription_static()

      • description_static

        public static java.lang.String description_static()

      • hash_static

        public static long hash_static()

      • instanceMethodSignatureForSelector

        public static NSMethodSignature instanceMethodSignatureForSelector​(org.moe.natj.objc.SEL aSelector)

      • instancesRespondToSelector

        public static boolean instancesRespondToSelector​(org.moe.natj.objc.SEL aSelector)

      • isSubclassOfClass

        public static boolean isSubclassOfClass​(org.moe.natj.objc.Class aClass)

      • keyPathsForValuesAffectingValueForKey

        public static NSSet<java.lang.String> keyPathsForValuesAffectingValueForKey​(java.lang.String key)

      • new_objc

        public static java.lang.Object new_objc()

      • resolveClassMethod

        public static boolean resolveClassMethod​(org.moe.natj.objc.SEL sel)

      • resolveInstanceMethod

        public static boolean resolveInstanceMethod​(org.moe.natj.objc.SEL sel)

      • setVersion_static

        public static void setVersion_static​(long aVersion)

      • superclass_static

        public static org.moe.natj.objc.Class superclass_static()

      • version_static

        public static long version_static()

      • addRule

        public void addRule​(GKRule rule)
        Adds a rule to the system. Also adds it to the agenda in salience order.

      • addRulesFromArray

        public void addRulesFromArray​(NSArray<? extends GKRule> rules)
        Adds rules to the system. Also adds them to the agenda in salience order.

      • agenda

        public NSArray<? extends GKRule> agenda()
        The current set of rules to be evaluated, in salience order, where if the salience is equivalent the order of insertion into the agenda is used to decide which is first. Adjust salience of your rules to adjust the order the next time the agenda is reset. Changing salience on a rule currently in the agenda does not change its order in the agenda. This is at all times the difference between the rules and executed sets.
        See Also:
        rules(), executed(), reset()

      • assertFact

        public void assertFact​(NSObject fact)
        Asserts a fact with membership grade of 1.0. This will cause the current rules to be evaluated, which may in turn assert or retract more facts or change the state of the system. This is shorthand for calling assertFact:grade: with a grade of 1.0
        See Also:
        evaluate()

      • assertFactGrade

        public void assertFactGrade​(NSObject fact,
                            float grade)
        Asserts a fact with the supplied membership grade. This will cause the current rules to be evaluated, which may in turn assert or retract more facts or change the state of the system.
        See Also:
        evaluate()

      • evaluate

        public void evaluate()
        Explicitly evaluate the agenda of the rule system based on the current state and the current set of facts. This may in turn assert or retract more facts or change the state of the system, including activating more rules in the agenda.

      • executed

        public NSArray<? extends GKRule> executed()
        The current set of rules that have already executed. Rules in this set will not be executed again until the system is reset. This is at all times the difference between the rules and agenda sets.
        See Also:
        rules(), agenda(), reset()

      • facts

        public NSArray<?> facts()
        The current set of facts. Facts have a grade of membership that is >= 0.0. Query the system for the individual grades of membership with gradeForFact:

      • gradeForFact

        public float gradeForFact​(NSObject fact)
        Returns the current membership grade for the given fact, which is 0.0 if the fact is not a member of the current set of facts.
        Returns:
        The membership grade of the given fact, in the range [0.0, 1.0].

      • init

        public GKRuleSystem init()
        Initializes a clean rule system with no state, rules or facts.
        Overrides:
        init in class NSObject

      • maximumGradeForFacts

        public float maximumGradeForFacts​(NSArray<?> facts)
        Returns the maximum membership grade for the any one of the given facts. This performs the logical OR operation between the given facts.
        Returns:
        The membership grade by applying the OR operator on the given facts, in the range [0.0, 1.0].

      • minimumGradeForFacts

        public float minimumGradeForFacts​(NSArray<?> facts)
        Returns the combined membership grade for the all the given facts. This performs the logical AND operation between the given facts.
        Returns:
        The membership grade by applying the AND operator on the given facts, in the range [0.0, 1.0].

      • removeAllRules

        public void removeAllRules()
        Removes all rules from the system. This also removes them from the agenda and executed sets.

      • reset

        public void reset()
        Clears the agenda and executed sets and removes all facts currently in the system. It then fills the agenda with rules from the rule set, in salience order.
        See Also:
        rules(), facts()

      • retractFact

        public void retractFact​(NSObject fact)
        Retracts a fact, setting its membership grade to 0, which also removes it from the fact set. This will cause the current rules to be evaluated, which may in turn assert or retract more facts or change the state of the system. This is short hand for calling retractFact:grade: with a grade of 1.0
        See Also:
        evaluate()

      • retractFactGrade

        public void retractFactGrade​(NSObject fact,
                             float grade)
        Retracts a fact, reducing its membership grade by the supplied grade. If this brings the grade to 0 it is also removed from the fact set. This will cause the current rules to be evaluated, which may in turn assert or retract more facts or change the state of the system.
        See Also:
        evaluate()

      • rules

        public NSArray<? extends GKRule> rules()
        The current set of rules that will be used to set the agenda when rules are first added to the system. They will also be used to refill the agenda whenever it is set. This is at all times the union of the agenda and executed sets.
        See Also:
        agenda(), executed()

      • state

        public NSMutableDictionary<?,​?> state()
        The implementation-defined state. If any changes are made on this outside the system you must call evaluate to have the system take account of the changes.
        See Also:
        evaluate()