org.apache.lucene.util.automaton

Class LevenshteinAutomata.ParametricDescription

java.lang.Object

org.apache.lucene.util.automaton.LevenshteinAutomata.ParametricDescription

Direct Known Subclasses:

Lev1ParametricDescription, Lev1TParametricDescription, Lev2ParametricDescription, Lev2TParametricDescription

Enclosing class:

LevenshteinAutomata

abstract static class LevenshteinAutomata.ParametricDescription
extends java.lang.Object

A ParametricDescription describes the structure of a Levenshtein DFA for some degree n.

There are four components of a parametric description, all parameterized on the length of the word w:

1. The number of states: size()
2. The set of final states: isAccept(int)
3. The transition function: transition(int, int, int)
4. Minimal boundary function: getPosition(int)

Field Summary

Fields

Modifier and Type	Field and Description
private static long[]	MASKS
private int[]	minErrors
protected int	n
protected int	w

Constructor Summary

Constructors

Constructor and Description
ParametricDescription(int w, int n, int[] minErrors)

Method Summary

Modifier and Type	Method and Description
(package private) int	getPosition(int absState) Returns the position in the input word for a given state.
(package private) boolean	isAccept(int absState) Returns true if the state in any Levenshtein DFA is an accept state (final state).
(package private) int	size() Return the number of states needed to compute a Levenshtein DFA
(package private) abstract int	transition(int state, int position, int vector) Returns the state number for a transition from the given state, assuming position and characteristic vector vector
protected int	unpack(long[] data, int index, int bitsPerValue)

Methods inherited from class java.lang.Object

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

Field Detail

w

protected final int w

n

protected final int n

minErrors

private final int[] minErrors

MASKS

private static final long[] MASKS

Constructor Detail

ParametricDescription

ParametricDescription(int w,
                      int n,
                      int[] minErrors)

Method Detail

size

int size()

Return the number of states needed to compute a Levenshtein DFA

isAccept

boolean isAccept(int absState)

Returns true if the state in any Levenshtein DFA is an accept state (final state).

getPosition

int getPosition(int absState)

Returns the position in the input word for a given state. This is the minimal boundary for the state.

transition

abstract int transition(int state,
                        int position,
                        int vector)

Returns the state number for a transition from the given state, assuming position and characteristic vector vector

unpack

protected int unpack(long[] data,
                     int index,
                     int bitsPerValue)