Class FuzzyTermsEnum

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Inheritance

object

TermsEnum

FuzzyTermsEnum

Implements

IBytesRefEnumerator

Inherited Members

TermsEnum.Attributes

TermsEnum.Docs(IBits, DocsEnum)

TermsEnum.DocsAndPositions(IBits, DocsAndPositionsEnum)

TermsEnum.EMPTY

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Lucene.Net.Search

Assembly: Lucene.Net.dll

Syntax

public class FuzzyTermsEnum : TermsEnum, IBytesRefEnumerator

Constructors

FuzzyTermsEnum(Terms, AttributeSource, Term, float, int, bool)

Constructor for enumeration of all terms from specified reader which share a prefix of length prefixLength with term and which have a fuzzy similarity > minSimilarity.

After calling the constructor the enumeration is already pointing to the first valid term if such a term exists.

Declaration

public FuzzyTermsEnum(Terms terms, AttributeSource atts, Term term, float minSimilarity, int prefixLength, bool transpositions)

Parameters

Type	Name	Description
Terms	terms	Delivers terms.
AttributeSource	atts	AttributeSource created by the rewrite method of MultiTermQuery thats contains information about competitive boosts during rewrite. It is also used to cache DFAs between segment transitions.
Term	term	Pattern term.
float	minSimilarity	Minimum required similarity for terms from the reader. Pass an integer value representing edit distance. Passing a fraction is deprecated.
int	prefixLength	Length of required common prefix. Default value is 0.
bool	transpositions	Transpositions

Exceptions

Type	Condition
IOException	if there is a low-level IO error

Fields

m_maxEdits

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected int m_maxEdits

Field Value

Type	Description
int

m_minSimilarity

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly float m_minSimilarity

Field Value

Type	Description
float

m_raw

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly bool m_raw

Field Value

Type	Description
bool

m_realPrefixLength

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly int m_realPrefixLength

Field Value

Type	Description
int

m_scaleFactor

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly float m_scaleFactor

Field Value

Type	Description
float

m_termLength

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly int m_termLength

Field Value

Type	Description
int

m_termText

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly int[] m_termText

Field Value

Type	Description
int[]

m_terms

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected readonly Terms m_terms

Field Value

Type	Description
Terms

Properties

Comparer

Return the BytesRef Comparer used to sort terms provided by the iterator. This may return null if there are no items or the iterator is not sorted. Callers may invoke this method many times, so it's best to cache a single instance & reuse it.

Declaration

public override IComparer<BytesRef> Comparer { get; }

Property Value

Type	Description
IComparer<BytesRef>

Overrides

TermsEnum.Comparer

DocFreq

Returns the number of documents containing the current term. Do not call this when the enum is unpositioned.

Declaration

public override int DocFreq { get; }

Property Value

Type	Description
int

Overrides

TermsEnum.DocFreq

See Also

END

MinSimilarity

Note

This API is for internal purposes only and might change in incompatible ways in the next release.

Declaration

public virtual float MinSimilarity { get; }

Property Value

Type	Description
float

Ord

Returns ordinal position for current term. This is an optional property (the codec may throw NotSupportedException. Do not call this when the enum is unpositioned.

Declaration

public override long Ord { get; }

Property Value

Type	Description
long

Overrides

TermsEnum.Ord

ScaleFactor

Note

This API is for internal purposes only and might change in incompatible ways in the next release.

Declaration

public virtual float ScaleFactor { get; }

Property Value

Type	Description
float

Term

Returns current term. Do not call this when the enum is unpositioned.

Declaration

public override BytesRef Term { get; }

Property Value

Type	Description
BytesRef

Overrides

TermsEnum.Term

TotalTermFreq

Returns the total number of occurrences of this term across all documents (the sum of the Freq for each doc that has this term). This will be -1 if the codec doesn't support this measure. Note that, like other term measures, this measure does not take deleted documents into account.

Declaration

public override long TotalTermFreq { get; }

Property Value

Type	Description
long

Overrides

TermsEnum.TotalTermFreq

Methods

Docs(IBits, DocsEnum, DocsFlags)

Get DocsEnum for the current term, with control over whether freqs are required. Do not call this when the enum is unpositioned. This method will not return null.

Declaration

public override DocsEnum Docs(IBits liveDocs, DocsEnum reuse, DocsFlags flags)

Parameters

Type	Name	Description
IBits	liveDocs	Unset bits are documents that should not be returned
DocsEnum	reuse	Pass a prior DocsEnum for possible reuse
DocsFlags	flags	Specifies which optional per-document values you require; DocsFlags

Returns

Type	Description
DocsEnum

Overrides

TermsEnum.Docs(IBits, DocsEnum, DocsFlags)

See Also

Docs(IBits, DocsEnum)

DocsAndPositions(IBits, DocsAndPositionsEnum, DocsAndPositionsFlags)

Get DocsAndPositionsEnum for the current term, with control over whether offsets and payloads are required. Some codecs may be able to optimize their implementation when offsets and/or payloads are not required. Do not call this when the enum is unpositioned. This will return null if positions were not indexed.

Declaration

public override DocsAndPositionsEnum DocsAndPositions(IBits liveDocs, DocsAndPositionsEnum reuse, DocsAndPositionsFlags flags)

Parameters

Type	Name	Description
IBits	liveDocs	Unset bits are documents that should not be returned
DocsAndPositionsEnum	reuse	Pass a prior DocsAndPositionsEnum for possible reuse
DocsAndPositionsFlags	flags	Specifies which optional per-position values you require; see DocsAndPositionsFlags.

Returns

Type	Description
DocsAndPositionsEnum

Overrides

TermsEnum.DocsAndPositions(IBits, DocsAndPositionsEnum, DocsAndPositionsFlags)

GetAutomatonEnum(int, BytesRef)

Return an automata-based enum for matching up to editDistance from lastTerm, if possible

Declaration

protected virtual TermsEnum GetAutomatonEnum(int editDistance, BytesRef lastTerm)

Parameters

Type	Name	Description
int	editDistance
BytesRef	lastTerm

Returns

Type	Description
TermsEnum

GetTermState()

Expert: Returns the TermsEnums internal state to position the TermsEnum without re-seeking the term dictionary.

NOTE: A seek by GetTermState() might not capture the AttributeSource's state. Callers must maintain the AttributeSource states separately

Declaration

public override TermState GetTermState()

Returns

Type	Description
TermState

Overrides

TermsEnum.GetTermState()

See Also

TermState

SeekExact(BytesRef, TermState)

MaxEditDistanceChanged(BytesRef, int, bool)

Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

Term enumerations are always ordered by Comparer. Each term in the enumeration is greater than all that precede it.

Declaration

protected virtual void MaxEditDistanceChanged(BytesRef lastTerm, int maxEdits, bool init)

Parameters

Type	Name	Description
BytesRef	lastTerm
int	maxEdits
bool	init

MoveNext()

Moves to the next item in the TermsEnum.

The default implementation can and should be overridden with a more optimized version.

Declaration

public override bool MoveNext()

Returns

Type	Description
bool	true if the enumerator was successfully advanced to the next element; false if the enumerator has passed the end of the collection.

Overrides

TermsEnum.MoveNext()

SeekCeil(BytesRef)

Seeks to the specified term, if it exists, or to the next (ceiling) term. Returns TermsEnum.SeekStatus to indicate whether exact term was found, a different term was found, or EOF was hit. The target term may be before or after the current term. If this returns END, the enum is unpositioned.

Declaration

public override TermsEnum.SeekStatus SeekCeil(BytesRef text)

Parameters

Type	Name	Description
BytesRef	text

Returns

Type	Description
TermsEnum.SeekStatus

Overrides

TermsEnum.SeekCeil(BytesRef)

SeekExact(BytesRef)

Attempts to seek to the exact term, returning true if the term is found. If this returns false, the enum is unpositioned. For some codecs, SeekExact(BytesRef) may be substantially faster than SeekCeil(BytesRef).

Declaration

public override bool SeekExact(BytesRef text)

Parameters

Type	Name	Description
BytesRef	text

Returns

Type	Description
bool

Overrides

TermsEnum.SeekExact(BytesRef)

SeekExact(BytesRef, TermState)

Expert: Seeks a specific position by TermState previously obtained from GetTermState(). Callers should maintain the TermState to use this method. Low-level implementations may position the TermsEnum without re-seeking the term dictionary.

Seeking by TermState should only be used iff the state was obtained from the same TermsEnum instance.

NOTE: Using this method with an incompatible TermState might leave this TermsEnum in undefined state. On a segment level TermState instances are compatible only iff the source and the target TermsEnum operate on the same field. If operating on segment level, TermState instances must not be used across segments.

NOTE: A seek by TermState might not restore the AttributeSource's state. AttributeSource states must be maintained separately if this method is used.

Declaration

public override void SeekExact(BytesRef term, TermState state)

Parameters

Type	Name	Description
BytesRef	term	the term the TermState corresponds to
TermState	state	the TermState

Overrides

TermsEnum.SeekExact(BytesRef, TermState)

SeekExact(long)

Seeks to the specified term by ordinal (position) as previously returned by Ord. The target ord may be before or after the current ord, and must be within bounds.

Declaration

public override void SeekExact(long ord)

Parameters

Type	Name	Description
long	ord

Overrides

TermsEnum.SeekExact(long)

SetEnum(TermsEnum)

Swap in a new actual enum to proxy to

Declaration

protected virtual void SetEnum(TermsEnum actualEnum)

Parameters

Type	Name	Description
TermsEnum	actualEnum

Implements

IBytesRefEnumerator