org.apache.lucene.util.automaton

Class Automaton.Builder

java.lang.Object

org.apache.lucene.util.automaton.Automaton.Builder

Enclosing class:

Automaton

public static class Automaton.Builder
extends Object

Records new states and transitions and then finish() creates the Automaton. Use this when you cannot create the Automaton directly because it's too restrictive to have to add all transitions leaving each state at once.

Constructor Summary

Constructors

Constructor and Description
Builder() Default constructor, pre-allocating for 16 states and transitions.
Builder(int numStates, int numTransitions) Constructor which creates a builder with enough space for the given number of states and transitions.

Method Summary

Modifier and Type	Method and Description
void	addEpsilon(int source, int dest) Add a [virtual] epsilon transition between source and dest.
void	addTransition(int source, int dest, int label) Add a new transition with min = max = label.
void	addTransition(int source, int dest, int min, int max) Add a new transition with the specified source, dest, min, max.
void	copy(Automaton other) Copies over all states/transitions from other.
void	copyStates(Automaton other) Copies over all states from other.
int	createState() Create a new state.
Automaton	finish() Compiles all added states and transitions into a new Automaton and returns it.
int	getNumStates() How many states this automaton has.
boolean	isAccept(int state) Returns true if this state is an accept state.
void	setAccept(int state, boolean accept) Set or clear this state as an accept state.

Methods inherited from class java.lang.Object

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

Constructor Detail

Builder

public Builder()

Default constructor, pre-allocating for 16 states and transitions.

Builder

public Builder(int numStates,
               int numTransitions)

Constructor which creates a builder with enough space for the given number of states and transitions.

Parameters:

numStates - Number of states.

numTransitions - Number of transitions.

Method Detail

addTransition

public void addTransition(int source,
                          int dest,
                          int label)

Add a new transition with min = max = label.

addTransition

public void addTransition(int source,
                          int dest,
                          int min,
                          int max)

Add a new transition with the specified source, dest, min, max.

addEpsilon

public void addEpsilon(int source,
                       int dest)

Add a [virtual] epsilon transition between source and dest. Dest state must already have all transitions added because this method simply copies those same transitions over to source.

finish

public Automaton finish()

Compiles all added states and transitions into a new Automaton and returns it.

createState

public int createState()

Create a new state.

setAccept

public void setAccept(int state,
                      boolean accept)

Set or clear this state as an accept state.

isAccept

public boolean isAccept(int state)

Returns true if this state is an accept state.

getNumStates

public int getNumStates()

How many states this automaton has.

copy

public void copy(Automaton other)

Copies over all states/transitions from other.

copyStates

public void copyStates(Automaton other)

Copies over all states from other.