gate.fsm
Class FSMInstance

java.lang.Object
  gate.fsm.FSMInstance

All Implemented Interfaces:

Serializable, Cloneable, Comparable

public class FSMInstance
extends Object
implements Comparable, Cloneable, Serializable

The objects of this class represent instances of working Finite State Machine during parsing a gate document (annotation set). In order to completely define the state a FSM is in one needs to store information regarding: -the position in the FSM transition graph -the position in the annotation graph -the set of bindings that occured up to the current state. note that a set of bindings is an object of type Map that maps names (java.lang.String) to bags of annotations (gate.AnnotationSet)

See Also:

Serialized Form

Constructor Summary

FSMInstance(FSM supportGraph, State FSMPosition, Node startNode, Node AGPosition, HashMap bindings, Document document)
Creates a new FSMInstance object.

Method Summary

static void	clearInstances() Release all the FSMInstances that are not currently in use
Object	clone() Returns a clone of this object.
int	compareTo(Object obj) Implementation of the compareTo method required by the Comparable interface.
boolean	equals(Object other)
Node	getAGPosition() Returns the node up to which this FSM instance advanced in the Annotation graph during the matching process.
HashMap	getBindings() Gets the map representing the bindings that took place during the matching process this FSM instance performed.
int	getFileIndex() Returns the index in the Jape definition file of the rule that caused the generation of the FSM state this instance is in.
State	getFSMPosition() Returns the position in the support graph for this FSM instance
long	getLength() Returns the length of the parsed region in the document under scrutiny.
static FSMInstance	getNewInstance(FSM supportGraph, State FSMPosition, Node startNode, Node AGPosition, HashMap bindings, Document doc) Static method that provides new FSM instances.
Node	getStartAGPosition() Returns the node in the AnnotationSet from which this FSM instance started the matching process.
FSM	getSupportGraph() Returns the FSM transition graph that backs this FSM instance
int	hashCode() Overrides the hashCode method from Object so this obejcts can be stored in hash maps and hash sets.
static void	returnInstance(FSMInstance ins) Static method used to return a FSMInstance that is not needed anymore
void	setAGPosition(Node node) Sets the current position in the AnnotationSet.
void	setFSMPosition(State newFSMPos) Sets the position in the support transition graph for this FSM instance Convenience method for when the state is not known at construction time.
String	toString() Returns a textual representation of this FSM instance.

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

FSMInstance

public FSMInstance(FSM supportGraph,
                   State FSMPosition,
                   Node startNode,
                   Node AGPosition,
                   HashMap bindings,
                   Document document)

Creates a new FSMInstance object.

Parameters:

supportGraph - the transition graph of the FSM

FSMPosition - the state this instance will be in

startNode - the node in the AnnotationSet where this FSM instance started the matching

AGPosition - the node in the AnnotationSet up to which this FSM Instance advanced during the matching.

bindings - a HashMap that maps from labels (objects of type String) to sets of annotations (objects of type AnnotationSet). This map stores all the bindings that took place during the matching process. This FSMInstance started the matching on an AnnotationSet from "startNode" and advanced to "AGPosition"; during this process it traversed the path in the transition graph "supportGraph" from the initial state to "FSMPosition" and made the bindings stored in "bindings".

Method Detail

getSupportGraph

public FSM getSupportGraph()

Returns the FSM transition graph that backs this FSM instance

Returns:

an FSM object

getFSMPosition

public State getFSMPosition()

Returns the position in the support graph for this FSM instance

Returns:

an object of type State

setFSMPosition

public void setFSMPosition(State newFSMPos)

Sets the position in the support transition graph for this FSM instance Convenience method for when the state is not known at construction time.

getFileIndex

public int getFileIndex()

Returns the index in the Jape definition file of the rule that caused the generation of the FSM state this instance is in. This value is correct if and only if this FSM instance is in a final state of the FSM transition graph.

Returns:

an int value.

getStartAGPosition

public Node getStartAGPosition()

Returns the node in the AnnotationSet from which this FSM instance started the matching process.

Returns:

a gate.Node object

getAGPosition

public Node getAGPosition()

Returns the node up to which this FSM instance advanced in the Annotation graph during the matching process.

Returns:

a gate.Node object

setAGPosition

public void setAGPosition(Node node)

Sets the current position in the AnnotationSet. Convenience method for cases when this value is not known at construction time.

Parameters:

node - a position in the AnnotationSet

getBindings

public HashMap getBindings()

Gets the map representing the bindings that took place during the matching process this FSM instance performed.

Returns:

a HashMap object

getLength

public long getLength()

Returns the length of the parsed region in the document under scrutiny. More precisely this is the distnace between the Node in the annotation graph where the matching started and the current position.

Returns:

a long value

hashCode

public int hashCode()

Overrides the hashCode method from Object so this obejcts can be stored in hash maps and hash sets.

Overrides:

hashCode in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object

clone

public Object clone()

Returns a clone of this object. The cloning is done bitwise except for the bindings that are cloned by themselves

Overrides:

clone in class Object

Returns:

an Object value that is actually a FSMInstance object

compareTo

public int compareTo(Object obj)

Implementation of the compareTo method required by the Comparable interface. The comparison is based on the size of the matched region and the index in the definition file of the rule associated to this FSM instance (which needs to be in a final state) The order imposed by this method is the priority needed in case of a multiple match.

Specified by:

compareTo in interface Comparable

toString

public String toString()

Returns a textual representation of this FSM instance.

Overrides:

toString in class Object

getNewInstance

public static FSMInstance getNewInstance(FSM supportGraph,
                                         State FSMPosition,
                                         Node startNode,
                                         Node AGPosition,
                                         HashMap bindings,
                                         Document doc)

Static method that provides new FSM instances. This method handles some basic object pooling in order to reuse the FSMInstance objects. This is considered to be a good idea because during jape transducing a large number of FSMIntances are needed for short periods.

returnInstance

public static void returnInstance(FSMInstance ins)

Static method used to return a FSMInstance that is not needed anymore

clearInstances

public static void clearInstances()

Release all the FSMInstances that are not currently in use