Package org.apache.lucene.search.spell

# Class LuceneLevenshteinDistance

java.lang.Object
org.apache.lucene.search.spell.LuceneLevenshteinDistance

All Implemented Interfaces:
  `StringDistance`

public final class LuceneLevenshteinDistance extends Object implements StringDistance
Damerau-Levenshtein (optimal string alignment) implemented in a consistent way as Lucene's FuzzyTermsEnum with the transpositions option enabled.

Notes:

- This metric treats full unicode codepoints as characters
- This metric scales raw edit distances into a floating point score based upon the shortest of the two terms
- Transpositions of two adjacent codepoints are treated as primitive edits.
- Edits are applied in parallel: for example, "ab" and "bca" have distance 3.

NOTE: this class is not particularly efficient. It is only intended for merging results from multiple DirectSpellCheckers.

## Constructor Summary

Constructors
Constructor
Description
`LuceneLevenshteinDistance()`
Creates a new comparator, mimicing the behavior of Lucene's internal edit distance.

## Method Summary

Modifier and Type
Method
Description
`boolean`
`equals(Object obj)`
`float`
`getDistance(String target, String other)`
Returns a float between 0 and 1 based on how similar the specified strings are to one another.
`int`
`hashCode()`

### Methods inherited from class java.lang.Object

`clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait`

## Constructor Details

### LuceneLevenshteinDistance

public LuceneLevenshteinDistance()
Creates a new comparator, mimicing the behavior of Lucene's internal edit distance.

## Method Details

### getDistance

public float getDistance(String target, String other)
Description copied from interface: `StringDistance`
Returns a float between 0 and 1 based on how similar the specified strings are to one another. Returning a value of 1 means the specified strings are identical and 0 means the string are maximally different.

Specified by:
  `getDistance` in interface `StringDistance`
Parameters:
  `target` - The first string.
  `other` - The second string.
Returns:
  a float between 0 and 1 based on how similar the specified strings are to one another.

### equals

public boolean equals(Object obj)

Overrides:
  `equals` in class `Object`

### hashCode

public int hashCode()

Overrides:
  `hashCode` in class `Object`