Class QueryTermExtractor

Utility class used to extract the terms used in a query, plus any weights. This class will not find terms for Lucene.Net.Search.MultiTermQuery, RangeQuery and Lucene.Net.Search.PrefixQuery classes so the caller must pass a rewritten query (see Lucene.Net.Search.Query.Rewrite(Lucene.Net.Index.IndexReader)) to obtain a list of expanded terms.

Inheritance

object

QueryTermExtractor

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Search.Highlight

Assembly: Lucene.Net.Highlighter.dll

Syntax

public static class QueryTermExtractor

Methods

GetIdfWeightedTerms(Query, IndexReader, string)

Extracts all terms texts of a given Lucene.Net.Search.Query into an array of WeightedTerms

Declaration

public static WeightedTerm[] GetIdfWeightedTerms(Query query, IndexReader reader, string fieldName)

Parameters

Type	Name	Description
Query	query	Lucene.Net.Search.Query to extract term texts from
IndexReader	reader	used to compute IDF which can be used to a) score selected fragments better b) use graded highlights eg chaning intensity of font color
string	fieldName	the field on which Inverse Document Frequency (IDF) calculations are based

Returns

Type	Description
WeightedTerm[]	an array of the terms used in a query, plus their weights.

GetTerms(Query)

Extracts all terms texts of a given Lucene.Net.Search.Query into an array of WeightedTerms

Declaration

public static WeightedTerm[] GetTerms(Query query)

Parameters

Type	Name	Description
Query	query	Lucene.Net.Search.Query to extract term texts from

Returns

Type	Description
WeightedTerm[]	an array of the terms used in a query, plus their weights.

GetTerms(Query, bool)

Extracts all terms texts of a given Lucene.Net.Search.Query into an array of WeightedTerms

Declaration

public static WeightedTerm[] GetTerms(Query query, bool prohibited)

Parameters

Type	Name	Description
Query	query	Lucene.Net.Search.Query to extract term texts from
bool	prohibited	true to extract "prohibited" terms, too

Returns

Type	Description
WeightedTerm[]	an array of the terms used in a query, plus their weights.

GetTerms(Query, bool, string)

Extracts all terms texts of a given Lucene.Net.Search.Query into an array of WeightedTerms

Declaration

public static WeightedTerm[] GetTerms(Query query, bool prohibited, string fieldName)

Parameters

Type	Name	Description
Query	query	Lucene.Net.Search.Query to extract term texts from
bool	prohibited	true to extract "prohibited" terms, too
string	fieldName	The fieldName used to filter query terms

Returns

Type	Description
WeightedTerm[]	an array of the terms used in a query, plus their weights.