org.apache.lucene.spelt

Class TRStringDistance2

Object

TRStringDistance2

final class TRStringDistance2
extends Object

Calculates the edit distance between two strings, with special modifications to score transpositions and double-letter changes as lower cost than insertion/deletion/replacement.

Author:

Martin Haye

Field Summary

Fields

Modifier and Type	Field and Description
(package private) int[][][]	cache
(package private) int	n
(package private) char[]	sa

Constructor Summary

Constructors

Constructor and Description
TRStringDistance2(String target) Optimized to run a bit faster than the static getDistance().

Method Summary

Modifier and Type	Method and Description
private static int[][]	form(int n, int m)
int	getDistance(String other) Compute Damerau-Levenstein distance between the target string and another string.
private static int	min3(int a, int b, int c)

Methods inherited from class Object

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

Field Detail

sa

final char[] sa

n

final int n

cache

final int[][][] cache

Constructor Detail

TRStringDistance2

public TRStringDistance2(String target)

Optimized to run a bit faster than the static getDistance(). In one benchmark times were 5.3sec using ctr vs 8.5sec w/ static method, thus 37% faster.

Method Detail

getDistance

public final int getDistance(String other)

Compute Damerau-Levenstein distance between the target string and another string. Damerau-Levenstein is similar to Levenstein except that it also accounts for transposition in the set of edit operations. This more fully reflects a common source of misspellings.

form

private static int[][] form(int n,
                            int m)

min3

private static int min3(int a,
                        int b,
                        int c)