Package ca.uqac.lif.cep.fsm

Class MooreMachine

  • All Implemented Interfaces:
    ca.uqac.lif.azrael.Printable, ca.uqac.lif.azrael.Readable, ca.uqac.lif.cep.Contextualizable, ca.uqac.lif.cep.Duplicable, ca.uqac.lif.cep.DuplicableProcessor, ca.uqac.lif.cep.Stateful
    public class MooreMachine
extends ca.uqac.lif.cep.SynchronousProcessor
implements ca.uqac.lif.cep.Stateful
    A finite-state automaton with output symbols associated to its states. Its input arity is not fixed to 1, i.e. it can read events from multiple traces at once. (Although, theoretically, this can be reduced to the unary case, so this is not a genuine generalization.)

    A "classical" finite-state automaton is a particular case of Moore machine where one simply ignores any output symbols. In that context, accepting and rejecting states can simply be associated to two different, arbitrary symbols (e.g. true and false).

    Author:
    Sylvain Hallé

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  MooreMachine.Transition
      Represents a transition in the Moore machine

      • Nested classes/interfaces inherited from class ca.uqac.lif.cep.SynchronousProcessor

        ca.uqac.lif.cep.SynchronousProcessor.InputPushable, ca.uqac.lif.cep.SynchronousProcessor.OutputPullable

      • Nested classes/interfaces inherited from class ca.uqac.lif.cep.Processor

        ca.uqac.lif.cep.Processor.InternalProcessorState

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected int m_currentState
      The current state the machine is in
      protected java.util.Set<ca.uqac.lif.cep.functions.ContextAssignment> m_initialAssignments
      The initial assignments given to each variable
      protected int m_initialState
      The initial state of the machine
      protected java.util.Map<java.lang.Integer,​java.lang.Integer> m_lastOccurrences
      A map storing the last event position for each state
      protected java.util.List<java.lang.Integer> m_looplessPath
      A map storing the last loopless path
      protected java.util.Map<java.lang.Integer,​ca.uqac.lif.cep.functions.Function[]> m_outputSymbols
      Associates output symbols to the states of the machine
      protected java.util.Map<java.lang.Integer,​java.util.List<MooreMachine.Transition>> m_relation
      A map from a state to the list of transitions from that state

      • Fields inherited from class ca.uqac.lif.cep.SynchronousProcessor

        m_inputPushables, m_outputPullables, m_tempQueue

      • Fields inherited from class ca.uqac.lif.cep.Processor

        m_context, m_eventTracker, m_hasBeenNotifiedOfEndOfTrace, m_inputArity, m_inputCount, m_inputPullables, m_inputQueues, m_notifiedEndOfTraceDownstream, m_outputArity, m_outputCount, m_outputPushables, m_outputQueues, MAX_PULL_RETRIES, s_versionString

    • Constructor Summary

      Constructors 
      Constructor Description
      MooreMachine​(int in_arity, int out_arity)  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addInitialAssignment​(ca.uqac.lif.cep.functions.ContextAssignment asg)  
      MooreMachine addSymbol​(int state, ca.uqac.lif.cep.functions.Function symbol)
      Associates an output symbol (i.e.
      MooreMachine addSymbols​(int state, ca.uqac.lif.cep.functions.Function... symbols)
      Associates output symbols (i.e.
      MooreMachine addTransition​(int source, MooreMachine.Transition t)
      Adds a transition to the machine
      protected void assignToContext​(ca.uqac.lif.cep.functions.ContextAssignment asg)  
      protected boolean compute​(java.lang.Object[] inputs, java.util.Queue<java.lang.Object[]> outputs)  
      MooreMachine duplicate​(boolean with_state)  
      protected boolean fire​(MooreMachine.Transition t, java.lang.Object[] inputs, java.lang.Object[] outputs)
      Fires a transition and updates the machine's state
      java.lang.Object getState()  
      void reset()  
      protected void updatePathHistory()  
      protected void updateProvenance()  

      • Methods inherited from class ca.uqac.lif.cep.SynchronousProcessor

        getPullableOutput, getPushableInput, setEventTracker

      • Methods inherited from class ca.uqac.lif.cep.Processor

        allNotifiedEndOfTrace, allNull, associateTo, associateToInput, associateToOutput, copyInputQueue, copyOutputQueue, duplicate, duplicateInto, equals, getAt, getContext, getContext, getEmptyQueue, getEventTracker, getId, getInputArity, getInputCount, getInputQueue, getInputType, getInputTypesFor, getLeaves, getLeaves, getOutputArity, getOutputCount, getOutputQueue, getOutputType, getPullableInput, getPullableOutput, getPushableInput, getPushableOutput, hashCode, leftShift, newContext, onEndOfTrace, or, or, print, printState, read, readState, rightShift, setContext, setContext, setPullableInput, setPushableOutput, start, startAll, stop, stopAll

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • m_relation

        protected java.util.Map<java.lang.Integer,​java.util.List<MooreMachine.Transition>> m_relation
        A map from a state to the list of transitions from that state

      • m_outputSymbols

        protected java.util.Map<java.lang.Integer,​ca.uqac.lif.cep.functions.Function[]> m_outputSymbols
        Associates output symbols to the states of the machine

      • m_currentState

        protected int m_currentState
        The current state the machine is in

      • m_initialState

        protected int m_initialState
        The initial state of the machine

      • m_lastOccurrences

        protected java.util.Map<java.lang.Integer,​java.lang.Integer> m_lastOccurrences
        A map storing the last event position for each state

      • m_looplessPath

        protected java.util.List<java.lang.Integer> m_looplessPath
        A map storing the last loopless path

      • m_initialAssignments

        protected java.util.Set<ca.uqac.lif.cep.functions.ContextAssignment> m_initialAssignments
        The initial assignments given to each variable

    • Constructor Detail

      • MooreMachine

        public MooreMachine​(int in_arity,
                    int out_arity)

    • Method Detail

      • addInitialAssignment

        public void addInitialAssignment​(ca.uqac.lif.cep.functions.ContextAssignment asg)

      • assignToContext

        protected void assignToContext​(ca.uqac.lif.cep.functions.ContextAssignment asg)

      • reset

        public void reset()
        Overrides:
        reset in class ca.uqac.lif.cep.Processor

      • addSymbols

        public MooreMachine addSymbols​(int state,
                               ca.uqac.lif.cep.functions.Function... symbols)
        Associates output symbols (i.e. event) to a state of the Moore machine
        Parameters:
        state - The state
        symbols - The symbols to associate. This will be the output event produced whenever the machine takes a transition ending in that state. There should be as many symbols as the output arity of the machine
        Returns:
        A reference to the current Moore machine

      • addSymbol

        public MooreMachine addSymbol​(int state,
                              ca.uqac.lif.cep.functions.Function symbol)
        Associates an output symbol (i.e. event) to a state of the Moore machine
        Parameters:
        state - The state
        symbol - The symbol to associate. This will be the output event produced whenever the machine takes a transition ending in that state. There should be as many symbols as the output arity of the machine. Therefore this method should only be called on a Moore machine of output arity 1.
        Returns:
        A reference to the current Moore machine

      • addTransition

        public MooreMachine addTransition​(int source,
                                  MooreMachine.Transition t)
        Adds a transition to the machine
        Parameters:
        source - The source state
        t - The transition to add
        Returns:
        A reference to the current Moore machine

      • compute

        protected boolean compute​(java.lang.Object[] inputs,
                          java.util.Queue<java.lang.Object[]> outputs)
                   throws ca.uqac.lif.cep.ProcessorException
        Specified by:
        compute in class ca.uqac.lif.cep.SynchronousProcessor
        Throws:
        ca.uqac.lif.cep.ProcessorException

      • updatePathHistory

        protected void updatePathHistory()

      • updateProvenance

        protected void updateProvenance()

      • fire

        protected boolean fire​(MooreMachine.Transition t,
                       java.lang.Object[] inputs,
                       java.lang.Object[] outputs)
        Fires a transition and updates the machine's state
        Parameters:
        t - The transition to fire
        inputs - The inputs that caused the transition to fire
        outputs - Any output symbol associated with the destination state, null otherwise
        Returns:
        true if an output symbol is produced, false otherwise

      • duplicate

        public MooreMachine duplicate​(boolean with_state)
        Specified by:
        duplicate in interface ca.uqac.lif.cep.Duplicable
        Specified by:
        duplicate in class ca.uqac.lif.cep.Processor

      • getState

        public java.lang.Object getState()
        Specified by:
        getState in interface ca.uqac.lif.cep.Stateful