Package org.apache.lucene.search.suggest.document

Class FuzzyCompletionQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.suggest.document.CompletionQuery

org.apache.lucene.search.suggest.document.PrefixCompletionQuery

org.apache.lucene.search.suggest.document.FuzzyCompletionQuery

public class FuzzyCompletionQuery
extends PrefixCompletionQuery

A CompletionQuery that match documents containing terms within an edit distance of the specified prefix.

This query boost documents relative to how similar the indexed terms are to the provided prefix.

Example usage of querying an analyzed prefix within an edit distance of 1 of 'subg' against a field 'suggest_field' is as follows:

  CompletionQuery query = new FuzzyCompletionQuery(analyzer, new Term("suggest_field", "subg"));
 

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_MAX_EDITS	The default maximum number of edits for fuzzy suggestions.
static int	DEFAULT_MIN_FUZZY_LENGTH	The default minimum length of the key before any edits are allowed.
static int	DEFAULT_NON_FUZZY_PREFIX	The default prefix length where edits are not allowed.
static boolean	DEFAULT_TRANSPOSITIONS	The default transposition value passed to LevenshteinAutomata
static boolean	DEFAULT_UNICODE_AWARE	Measure maxEdits, minFuzzyLength, transpositions and nonFuzzyPrefix parameters in Unicode code points (actual letters) instead of bytes.

Fields inherited from class org.apache.lucene.search.suggest.document.PrefixCompletionQuery

analyzer

Constructor Summary

Constructors

Constructor	Description
FuzzyCompletionQuery(Analyzer analyzer, Term term)	Calls FuzzyCompletionQuery(Analyzer, Term, BitsProducer) with no filter
FuzzyCompletionQuery(Analyzer analyzer, Term term, BitsProducer filter)	Calls FuzzyCompletionQuery(Analyzer, Term, BitsProducer, int, boolean, int, int, boolean, int) with defaults for maxEdits, transpositions, nonFuzzyPrefix, minFuzzyLength, unicodeAware and maxDeterminizedStates See DEFAULT_MAX_EDITS, DEFAULT_TRANSPOSITIONS, DEFAULT_NON_FUZZY_PREFIX, DEFAULT_MIN_FUZZY_LENGTH, DEFAULT_UNICODE_AWARE and Operations.DEFAULT_MAX_DETERMINIZED_STATES for defaults
FuzzyCompletionQuery(Analyzer analyzer, Term term, BitsProducer filter, int maxEdits, boolean transpositions, int nonFuzzyPrefix, int minFuzzyLength, boolean unicodeAware, int maxDeterminizedStates)	Constructs an analyzed fuzzy prefix completion query

Method Summary

Modifier and Type	Method	Description
Weight	createWeight(IndexSearcher searcher, ScoreMode scoreMode, float boost)
int	getMaxDeterminizedStates()	Get the maximum number of determinized states permitted
int	getMaxEdits()	Get the maximum edit distance for fuzzy matches
int	getMinFuzzyLength()	Get the minimum length of a term considered for matching
int	getNonFuzzyPrefix()	Get the length of a prefix where no edits are permitted
boolean	isTranspositions()	Return whether transpositions count as a single edit
boolean	isUnicodeAware()	Return true if lengths are measured in unicode code-points rather than bytes
String	toString(String field)

Methods inherited from class org.apache.lucene.search.suggest.document.PrefixCompletionQuery

equals, getAnalyzer, hashCode, visit

Methods inherited from class org.apache.lucene.search.suggest.document.CompletionQuery

getField, getFilter, getTerm, rewrite

Methods inherited from class org.apache.lucene.search.Query

classHash, sameClassAs, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_UNICODE_AWARE

public static final boolean DEFAULT_UNICODE_AWARE

Measure maxEdits, minFuzzyLength, transpositions and nonFuzzyPrefix parameters in Unicode code points (actual letters) instead of bytes.

See Also:

Constant Field Values

DEFAULT_MIN_FUZZY_LENGTH

public static final int DEFAULT_MIN_FUZZY_LENGTH

The default minimum length of the key before any edits are allowed.

See Also:

Constant Field Values

DEFAULT_NON_FUZZY_PREFIX

public static final int DEFAULT_NON_FUZZY_PREFIX

The default prefix length where edits are not allowed.

See Also:

Constant Field Values

DEFAULT_MAX_EDITS

public static final int DEFAULT_MAX_EDITS

The default maximum number of edits for fuzzy suggestions.

See Also:

Constant Field Values

DEFAULT_TRANSPOSITIONS

public static final boolean DEFAULT_TRANSPOSITIONS

The default transposition value passed to LevenshteinAutomata

See Also:

Constant Field Values

Constructor Detail

FuzzyCompletionQuery

public FuzzyCompletionQuery(Analyzer analyzer,
                            Term term)

Calls FuzzyCompletionQuery(Analyzer, Term, BitsProducer) with no filter

FuzzyCompletionQuery

public FuzzyCompletionQuery(Analyzer analyzer,
                            Term term,
                            BitsProducer filter)

Calls FuzzyCompletionQuery(Analyzer, Term, BitsProducer, int, boolean, int, int, boolean, int) with defaults for maxEdits, transpositions, nonFuzzyPrefix, minFuzzyLength, unicodeAware and maxDeterminizedStates See DEFAULT_MAX_EDITS, DEFAULT_TRANSPOSITIONS, DEFAULT_NON_FUZZY_PREFIX, DEFAULT_MIN_FUZZY_LENGTH, DEFAULT_UNICODE_AWARE and Operations.DEFAULT_MAX_DETERMINIZED_STATES for defaults

FuzzyCompletionQuery

public FuzzyCompletionQuery(Analyzer analyzer,
                            Term term,
                            BitsProducer filter,
                            int maxEdits,
                            boolean transpositions,
                            int nonFuzzyPrefix,
                            int minFuzzyLength,
                            boolean unicodeAware,
                            int maxDeterminizedStates)

Constructs an analyzed fuzzy prefix completion query

Parameters:

analyzer - used to analyze the provided Term.text()

term - query is run against Term.field() and Term.text() is analyzed with analyzer

filter - used to query on a sub set of documents

maxEdits - maximum number of acceptable edits

transpositions - value passed to LevenshteinAutomata

nonFuzzyPrefix - prefix length where edits are not allowed

minFuzzyLength - minimum prefix length before any edits are allowed

unicodeAware - treat prefix as unicode rather than bytes

maxDeterminizedStates - maximum automaton states allowed for LevenshteinAutomata

Method Detail

createWeight

public Weight createWeight(IndexSearcher searcher,
                           ScoreMode scoreMode,
                           float boost)
                    throws IOException

Overrides:

createWeight in class PrefixCompletionQuery

Throws:

IOException

getMaxEdits

public int getMaxEdits()

Get the maximum edit distance for fuzzy matches

isTranspositions

public boolean isTranspositions()

Return whether transpositions count as a single edit

getNonFuzzyPrefix

public int getNonFuzzyPrefix()

Get the length of a prefix where no edits are permitted

getMinFuzzyLength

public int getMinFuzzyLength()

Get the minimum length of a term considered for matching

isUnicodeAware

public boolean isUnicodeAware()

Return true if lengths are measured in unicode code-points rather than bytes

getMaxDeterminizedStates

public int getMaxDeterminizedStates()

Get the maximum number of determinized states permitted

toString

public String toString(String field)

Overrides:

toString in class CompletionQuery