Class SpanNearClauseFactory

SpanNearClauseFactory:

Operations:

  • create for a field name and an indexreader.
  • add a weighted Term - this should add a corresponding SpanTermQuery, or increase the weight of an existing one.
  • add a weighted subquery SpanNearQuery
  • create a clause for SpanNearQuery from the things added above.

For this, create an array of SpanQuery's from the added ones. The clause normally is a SpanOrQuery over the added subquery SpanNearQuery the SpanTermQuery's for the added Term's

When it is necessary to suppress double subqueries as much as possible: GetHashCode() and Equals() on unweighted SpanQuery are needed (possibly via GetTerms(), the terms are individually hashable). Idem SpanNearQuery: hash on the subqueries and the slop. Evt. merge SpanNearQuery's by adding the weights of the corresponding subqueries.

To be determined: Are SpanQuery weights handled correctly during search by Lucene? Should the resulting SpanOrQuery be sorted? Could other SpanQueries be added for use in this factory:

  • SpanOrQuery: in principle yes, but it only has access to it's terms via getTerms(); are the corresponding weights available?
  • SpanFirstQuery: treat similar to subquery SpanNearQuery. (ok?)
  • SpanNotQuery: treat similar to subquery SpanNearQuery. (ok?)

Factory for SpanOrQuery

Inheritance
System.Object
SpanNearClauseFactory
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Lucene.Net.QueryParsers.Surround.Query
Assembly: Lucene.Net.QueryParser.dll
Syntax
public class SpanNearClauseFactory

Constructors

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SpanNearClauseFactory(IndexReader, String, BasicQueryFactory)

Declaration
public SpanNearClauseFactory(IndexReader reader, string fieldName, BasicQueryFactory qf)
Parameters
Type Name Description
Lucene.Net.Index.IndexReader reader
System.String fieldName
BasicQueryFactory qf

Properties

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BasicQueryFactory

Declaration
public virtual BasicQueryFactory BasicQueryFactory { get; }
Property Value
Type Description
BasicQueryFactory
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Count

Declaration
public virtual int Count { get; }
Property Value
Type Description
System.Int32
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FieldName

Declaration
public virtual string FieldName { get; }
Property Value
Type Description
System.String
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IndexReader

Declaration
public virtual IndexReader IndexReader { get; }
Property Value
Type Description
Lucene.Net.Index.IndexReader

Methods

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AddSpanQuery(Query)

Declaration
public virtual void AddSpanQuery(Query q)
Parameters
Type Name Description
Lucene.Net.Search.Query q
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AddSpanQueryWeighted(SpanQuery, Single)

Declaration
protected virtual void AddSpanQueryWeighted(SpanQuery sq, float weight)
Parameters
Type Name Description
Lucene.Net.Search.Spans.SpanQuery sq
System.Single weight
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AddTermWeighted(Term, Single)

Declaration
public virtual void AddTermWeighted(Term t, float weight)
Parameters
Type Name Description
Lucene.Net.Index.Term t
System.Single weight
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Clear()

Declaration
public virtual void Clear()
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MakeSpanClause()

Declaration
public virtual SpanQuery MakeSpanClause()
Returns
Type Description
Lucene.Net.Search.Spans.SpanQuery