Class SlowFuzzyQuery

Implements the classic fuzzy search query. The similarity measurement is based on the Levenshtein (edit distance) algorithm.

Note that, unlike Lucene.Net.Search.FuzzyQuery, this query will silently allow for a (possibly huge) number of edit distances in comparisons, and may be extremely slow (comparing every term in the index).

Inheritance

object

Query

MultiTermQuery

SlowFuzzyQuery

Inherited Members

MultiTermQuery.m_field

MultiTermQuery.m_rewriteMethod

MultiTermQuery.CONSTANT_SCORE_FILTER_REWRITE

MultiTermQuery.SCORING_BOOLEAN_QUERY_REWRITE

MultiTermQuery.CONSTANT_SCORE_BOOLEAN_QUERY_REWRITE

MultiTermQuery.CONSTANT_SCORE_AUTO_REWRITE_DEFAULT

MultiTermQuery.Field

MultiTermQuery.GetTermsEnum(Terms)

MultiTermQuery.Rewrite(IndexReader)

MultiTermQuery.MultiTermRewriteMethod

Query.Boost

Query.ToString()

Query.CreateWeight(IndexSearcher)

Query.ExtractTerms(ISet<Term>)

Query.Clone()

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Lucene.Net.Sandbox.Queries

Assembly: Lucene.Net.Sandbox.dll

Syntax

[Obsolete("Use FuzzyQuery instead.")]
public class SlowFuzzyQuery : MultiTermQuery

Constructors

SlowFuzzyQuery(Term)

Calls SlowFuzzyQuery(term, defaultMinSimilarity, 0, defaultMaxExpansions).

Declaration

public SlowFuzzyQuery(Term term)

Parameters

Type	Name	Description
Term	term

SlowFuzzyQuery(Term, float)

Calls SlowFuzzyQuery(term, minimumSimilarity, 0, defaultMaxExpansions).

Declaration

public SlowFuzzyQuery(Term term, float minimumSimilarity)

Parameters

Type	Name	Description
Term	term
float	minimumSimilarity

SlowFuzzyQuery(Term, float, int)

Calls SlowFuzzyQuery(term, minimumSimilarity, prefixLength, defaultMaxExpansions).

Declaration

public SlowFuzzyQuery(Term term, float minimumSimilarity, int prefixLength)

Parameters

Type	Name	Description
Term	term
float	minimumSimilarity
int	prefixLength

SlowFuzzyQuery(Term, float, int, int)

Create a new SlowFuzzyQuery that will match terms with a similarity of at least minimumSimilarity to term. If a prefixLength > 0 is specified, a common prefix of that length is also required.

Declaration

public SlowFuzzyQuery(Term term, float minimumSimilarity, int prefixLength, int maxExpansions)

Parameters

Type	Name	Description
Term	term	the term to search for
float	minimumSimilarity	a value between 0 and 1 to set the required similarity between the query term and the matching terms. For example, for a minimumSimilarity of 0.5 a term of the same length as the query term is considered similar to the query term if the edit distance between both terms is less than length(term)*0.5 Alternatively, if minimumSimilarity is >= 1f, it is interpreted as a pure Levenshtein edit distance. For example, a value of 2f will match all terms within an edit distance of 2 from the query term. Edit distances specified in this way may not be fractional.
int	prefixLength	length of common (non-fuzzy) prefix
int	maxExpansions	the maximum number of terms to match. If this number is greater than Lucene.Net.Search.BooleanQuery.MaxClauseCount when the query is rewritten, then the maxClauseCount will be used instead.

Exceptions

Type	Condition
ArgumentException	if minimumSimilarity is >= 1 or < 0 or if prefixLength < 0

Fields

defaultMaxExpansions

Implements the classic fuzzy search query. The similarity measurement is based on the Levenshtein (edit distance) algorithm.

Note that, unlike Lucene.Net.Search.FuzzyQuery, this query will silently allow for a (possibly huge) number of edit distances in comparisons, and may be extremely slow (comparing every term in the index).

Declaration

public const int defaultMaxExpansions = 50

Field Value

Type	Description
int

defaultMinSimilarity

Implements the classic fuzzy search query. The similarity measurement is based on the Levenshtein (edit distance) algorithm.

Note that, unlike Lucene.Net.Search.FuzzyQuery, this query will silently allow for a (possibly huge) number of edit distances in comparisons, and may be extremely slow (comparing every term in the index).

Declaration

public const float defaultMinSimilarity = 2

Field Value

Type	Description
float

defaultPrefixLength

Implements the classic fuzzy search query. The similarity measurement is based on the Levenshtein (edit distance) algorithm.

Note that, unlike Lucene.Net.Search.FuzzyQuery, this query will silently allow for a (possibly huge) number of edit distances in comparisons, and may be extremely slow (comparing every term in the index).

Declaration

public const int defaultPrefixLength = 0

Field Value

Type	Description
int

m_term

Implements the classic fuzzy search query. The similarity measurement is based on the Levenshtein (edit distance) algorithm.

Note that, unlike Lucene.Net.Search.FuzzyQuery, this query will silently allow for a (possibly huge) number of edit distances in comparisons, and may be extremely slow (comparing every term in the index).

Declaration

protected Term m_term

Field Value

Type	Description
Term

Properties

MinSimilarity

Gets the minimum similarity that is required for this query to match. Returns float value between 0.0 and 1.0.

Declaration

public virtual float MinSimilarity { get; }

Property Value

Type	Description
float

PrefixLength

Gets the non-fuzzy prefix length. This is the number of characters at the start of a term that must be identical (not fuzzy) to the query term if the query is to match that term.

Declaration

public virtual int PrefixLength { get; }

Property Value

Type	Description
int

Term

Gets the pattern term.

Declaration

public virtual Term Term { get; }

Property Value

Type	Description
Term

Methods

Equals(object)

Determines whether the specified object is equal to the current object.

Declaration

public override bool Equals(object obj)

Parameters

Type	Name	Description
object	obj	The object to compare with the current object.

Returns

Type	Description
bool	true if the specified object is equal to the current object; otherwise, false.

Overrides

MultiTermQuery.Equals(object)

GetHashCode()

Serves as the default hash function.

Declaration

public override int GetHashCode()

Returns

Type	Description
int	A hash code for the current object.

Overrides

Lucene.Net.Search.MultiTermQuery.GetHashCode()

GetTermsEnum(Terms, AttributeSource)

Construct the enumeration to be used, expanding the pattern term. this method should only be called if the field exists (ie, implementations can assume the field does exist). this method should not return null (should instead return Lucene.Net.Index.TermsEnum.EMPTY if no terms match). The Lucene.Net.Index.TermsEnum must already be positioned to the first matching term. The given Lucene.Net.Util.AttributeSource is passed by the Lucene.Net.Search.MultiTermQuery.RewriteMethod to provide attributes, the rewrite method uses to inform about e.g. maximum competitive boosts. this is currently only used by Lucene.Net.Search.TopTermsRewrite<Q>.

Declaration

protected override TermsEnum GetTermsEnum(Terms terms, AttributeSource atts)

Parameters

Type	Name	Description
Terms	terms
AttributeSource	atts

Returns

Type	Description
TermsEnum

Overrides

Lucene.Net.Search.MultiTermQuery.GetTermsEnum(Lucene.Net.Index.Terms, Lucene.Net.Util.AttributeSource)

ToString(string)

Prints a query to a string, with field assumed to be the default field and omitted.

Declaration

public override string ToString(string field)

Parameters

Type	Name	Description
string	field

Returns

Type	Description
string

Overrides

Query.ToString(string)