com.saxonica.schema.fsa
Class AutomatonState

java.lang.Object
  com.saxonica.schema.fsa.AutomatonState

All Implemented Interfaces:

State, Serializable

Direct Known Subclasses:

DeterminizedState, NonDeterminizedState

public abstract class AutomatonState
extends Object
implements State

Defines a state of a finite state machine used when validating an instance against a complex type. Each State knows about the possible transitions to other states, and knows whether it is a final state. The initial state is referenced from the FiniteStateMachine object, which is itself a property of the UserComplexType against which validation is being performed.

This class is designed for internal use only.

See Also:

Serialized Form

Field Summary

static Edge[]	EMPTY_EDGE_ARRAY
protected Edge[]	wildcardEdges

Constructor Summary

AutomatonState(FiniteStateMachine machine)
Create a new state

Method Summary

void	addSpecificTransition(Edge edge, SchemaCompiler compiler) Add a specific transition from this state to another state.
void	addWildcardTransition(SchemaCompiler compiler, Edge transition) Add a wildcard transition from this state to another state.
void	display(HashMap<AutomatonState,Integer> map) Display the finite state machine reachable from this state.
void	displayLambdaTransitions() Display the lambda transitions available from this state
void	displayState(PrintStream err) Display the finite state machine reachable from this state.
Iterator<Edge>	getEdges() Get an iterator over all the transitions (edges) allowed from this state
Edge	getMaxTransition() Get the transition to be used when the maxOccurs value is reached for a counting state.
int	getStateNumber() Get the state number
Edge	getTransition(int token, UserComplexType type) Find the edge representing the transition from this state to another state, that is triggered by a given input token
Edge[]	getWildcardEdges() Get an iterator over the wildcard transitions (edges) allowed from this state.
boolean	isConditionallyFinalState() Test whether this state is a final state assuming the counter has reached its minimum value
boolean	isFinalState() Test whether this state is a final state
CharSequence	listAllowedElements() List the allowed elements in this state as a string, for use in error messages
boolean	requiresCounter() Ask whether this is a counting state
void	serialize(SchemaModelSerializer serializer) Serialize this state as part of the serialization of a schema component model
void	setFinalState(boolean finalState) Set this state to be (or not to be) a final state
void	setLimits(int min, int max) Set the counter limits
void	setMaxTransition(Edge edge) A counting state may have a special Edge that is used when the maxOccurs value is reached.

Methods inherited from class java.lang.Object

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

Field Detail

wildcardEdges

protected Edge[] wildcardEdges

EMPTY_EDGE_ARRAY

public static final Edge[] EMPTY_EDGE_ARRAY

Constructor Detail

AutomatonState

public AutomatonState(FiniteStateMachine machine)

Create a new state

Parameters:

machine - the finite state machine to which this State belongs

Method Detail

isFinalState

public boolean isFinalState()

Test whether this state is a final state

Specified by:

isFinalState in interface State

Returns:

true if this is a final state

isConditionallyFinalState

public boolean isConditionallyFinalState()

Test whether this state is a final state assuming the counter has reached its minimum value

Returns:

true if this state is a final state when the minimum number of occurrences is reached

setFinalState

public void setFinalState(boolean finalState)

Set this state to be (or not to be) a final state

Parameters:

finalState - true if this state is final

getStateNumber

public int getStateNumber()

Get the state number

Returns:

the state number

addSpecificTransition

public void addSpecificTransition(Edge edge,
                                  SchemaCompiler compiler)
                           throws SchemaException

Add a specific transition from this state to another state. This transition accepts a specific element name only.

Parameters:

edge - the transition to be added

compiler - the schema compiler

Throws:

SchemaException - if there are two transitions for the same element declaration, that is, if the content model is ambiguous

addWildcardTransition

public void addWildcardTransition(SchemaCompiler compiler,
                                  Edge transition)
                           throws SchemaException

Add a wildcard transition from this state to another state.

Parameters:

compiler - the schema compiler

transition - the edge representing the transition

Throws:

SchemaException - if the transition cannot be added because it would generate an inconsistency

setLimits

public void setLimits(int min,
                      int max)

Set the counter limits

Parameters:

min - the minimum number of occurrences of counting edges before a non-counting edge is used

max - the maximum number of occurrences of counting edges before a non-counting edge is used; the value -1 means unbounded

requiresCounter

public boolean requiresCounter()

Ask whether this is a counting state

Returns:

true if this state requires a counter to be maintained

getTransition

public Edge getTransition(int token,
                          UserComplexType type)

Find the edge representing the transition from this state to another state, that is triggered by a given input token

Specified by:

getTransition in interface State

Parameters:

token - the input token, specifically the fingerprint of an element name

type - the complex type we are validating against

Returns:

the Edge representing the selected transition of the finite state machine, or null if this token is not accepted when in this State (which implies a validation error).

listAllowedElements

public CharSequence listAllowedElements()

List the allowed elements in this state as a string, for use in error messages

Specified by:

listAllowedElements in interface State

Returns:

the list of permitted elements as a string containing comma-separated element names

getWildcardEdges

public Edge[] getWildcardEdges()

Get an iterator over the wildcard transitions (edges) allowed from this state.

Specified by:

getWildcardEdges in interface State

Returns:

an Iterator over the edges that represent element wildcards. The objects returned by this Iterator are Edge objects.

getEdges

public Iterator<Edge> getEdges()

Get an iterator over all the transitions (edges) allowed from this state

Specified by:

getEdges in interface State

Returns:

an Iterator over all the edges from this state. The objects returned by this Iterator are Edge objects.

display

public void display(HashMap<AutomatonState,Integer> map)

Display the finite state machine reachable from this state. This is a diagnostic method for internal use. Output is written to System.err. At present, wildcard transitions are not shown.

Parameters:

map - a Hashmap mapping states already processed to the integer values used to represent that state. The method should be called initially with an empty map.

displayState

public void displayState(PrintStream err)

Display the finite state machine reachable from this state. This is a diagnostic method for internal use. Output is written to System.err. At present, wildcard transitions are not shown.

Parameters:

err - the output destination destination

displayLambdaTransitions

public void displayLambdaTransitions()

Display the lambda transitions available from this state

setMaxTransition

public void setMaxTransition(Edge edge)

A counting state may have a special Edge that is used when the maxOccurs value is reached. This method sets this edge.

Parameters:

edge - the transition to be used when the maxOccurs value is reached

getMaxTransition

public Edge getMaxTransition()

Get the transition to be used when the maxOccurs value is reached for a counting state.

Returns:

the max transition if there is one, else null.

serialize

public void serialize(SchemaModelSerializer serializer)
               throws XPathException

Serialize this state as part of the serialization of a schema component model

Parameters:

serializer - used to output the model

Throws:

XPathException - if any failure occurs