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A library for spelling-correction based on Levenshtein Automata.
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// Generated by delombok at Sun May 29 12:10:02 UTC 2016
package com.github.liblevenshtein.distance;
import com.github.liblevenshtein.collection.SymmetricImmutablePair;
/**
* Memoizes the distance between two terms, where the distance is calculated
* using the standard Levenshtein distance extended with merge and split.
* @author Dylon Edwards
* @since 2.1.0
*/
public class MemoizedMergeAndSplit extends AbstractMemoized {
private static final long serialVersionUID = 1L;
/**
* {@inheritDoc}
*/
@Override
@SuppressWarnings("checkstyle:finalparameters")
public int memoizedDistance(String v, String w) {
final com.github.liblevenshtein.collection.SymmetricImmutablePair key = new SymmetricImmutablePair(v, w);
int distance = memo.getInt(key);
if (distance != DEFAULT_RETURN_VALUE) {
return distance;
}
if (v.isEmpty()) {
distance = w.length();
memo.put(key, distance);
return distance;
}
if (w.isEmpty()) {
distance = v.length();
memo.put(key, distance);
return distance;
}
char a = v.charAt(0);
String x = v.substring(1);
char b = w.charAt(0);
String y = w.substring(1);
// Discard identical characters
while (a == b && x.length() > 0 && y.length() > 0) {
a = x.charAt(0);
v = x;
x = v.substring(1);
b = y.charAt(0);
w = y;
y = w.substring(1);
}
// x.length() == 0 or y.length() == 0
if (a == b) {
distance = x.isEmpty() ? y.length() : x.length();
memo.put(key, distance);
return distance;
}
distance = memoizedDistance(x, w);
if (0 == distance) {
memo.put(key, 1);
return 1;
}
int minDistance = distance;
distance = memoizedDistance(v, y);
if (0 == distance) {
memo.put(key, 1);
return 1;
}
if (distance < minDistance) {
minDistance = distance;
}
distance = memoizedDistance(x, y);
if (0 == distance) {
memo.put(key, 1);
return 1;
}
if (distance < minDistance) {
minDistance = distance;
}
if (w.length() > 1) {
distance = memoizedDistance(x, f(w, 1));
if (0 == distance) {
memo.put(key, 1);
return 1;
}
if (distance < minDistance) {
minDistance = distance;
}
}
if (v.length() > 1) {
distance = memoizedDistance(f(v, 1), y);
if (0 == distance) {
memo.put(key, 1);
return 1;
}
if (distance < minDistance) {
minDistance = distance;
}
}
distance = 1 + minDistance;
memo.put(key, distance);
return distance;
}
}