Class FuzzyTermsEnum
- All Implemented Interfaces:
BytesRefIterator
Term enumerations are always ordered by BytesRef.compareTo(org.apache.lucene.util.BytesRef)
. Each term in the
enumeration is greater than all that precede it.
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic class
Thrown to indicate that there was an issue creating a fuzzy query for a given term.Nested classes/interfaces inherited from class org.apache.lucene.index.TermsEnum
TermsEnum.SeekStatus
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Field Summary
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Constructor Summary
ConstructorsConstructorDescriptionFuzzyTermsEnum
(Terms terms, Term term, int maxEdits, int prefixLength, boolean transpositions) Constructor for enumeration of all terms from specifiedreader
which share a prefix of lengthprefixLength
withterm
and which have at mostmaxEdits
edits. -
Method Summary
Modifier and TypeMethodDescriptionReturns the related attributes.int
docFreq()
Returns the number of documents containing the current term.float
getBoost()
Gets the boost of the current termimpacts
(int flags) Return aImpactsEnum
.next()
Increments the iteration to the nextBytesRef
in the iterator.long
ord()
Returns ordinal position for current term.postings
(PostingsEnum reuse, int flags) GetPostingsEnum
for the current term, with control over whether freqs, positions, offsets or payloads are required.Seeks to the specified term, if it exists, or to the next (ceiling) term.void
seekExact
(long ord) Seeks to the specified term by ordinal (position) as previously returned byTermsEnum.ord()
.boolean
Attempts to seek to the exact term, returning true if the term is found.void
Expert: Seeks a specific position byTermState
previously obtained fromTermsEnum.termState()
.void
setMaxNonCompetitiveBoost
(float boost) Sets the maximum non-competitive boost, which may allow switching to a lower max-edit automaton at run timeterm()
Returns current term.Expert: Returns the TermsEnums internal state to position the TermsEnum without re-seeking the term dictionary.long
Returns the total number of occurrences of this term across all documents (the sum of the freq() for each doc that has this term).
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Constructor Details
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FuzzyTermsEnum
public FuzzyTermsEnum(Terms terms, Term term, int maxEdits, int prefixLength, boolean transpositions) throws IOException Constructor for enumeration of all terms from specifiedreader
which share a prefix of lengthprefixLength
withterm
and which have at mostmaxEdits
edits.After calling the constructor the enumeration is already pointing to the first valid term if such a term exists.
- Parameters:
terms
- Delivers terms.term
- Pattern term.maxEdits
- Maximum edit distance.prefixLength
- the length of the required common prefixtranspositions
- whether transpositions should count as a single edit- Throws:
IOException
- if there is a low-level IO error
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Method Details
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setMaxNonCompetitiveBoost
public void setMaxNonCompetitiveBoost(float boost) Sets the maximum non-competitive boost, which may allow switching to a lower max-edit automaton at run time -
getBoost
public float getBoost()Gets the boost of the current term -
next
Description copied from interface:BytesRefIterator
Increments the iteration to the nextBytesRef
in the iterator. Returns the resultingBytesRef
ornull
if the end of the iterator is reached. The returned BytesRef may be re-used across calls to next. After this method returns null, do not call it again: the results are undefined.- Returns:
- the next
BytesRef
in the iterator ornull
if the end of the iterator is reached. - Throws:
IOException
- If there is a low-level I/O error.
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docFreq
Description copied from class:TermsEnum
Returns the number of documents containing the current term. Do not call this when the enum is unpositioned.TermsEnum.SeekStatus.END
.- Specified by:
docFreq
in classTermsEnum
- Throws:
IOException
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totalTermFreq
Description copied from class:TermsEnum
Returns the total number of occurrences of this term across all documents (the sum of the freq() for each doc that has this term). Note that, like other term measures, this measure does not take deleted documents into account.- Specified by:
totalTermFreq
in classTermsEnum
- Throws:
IOException
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postings
Description copied from class:TermsEnum
GetPostingsEnum
for the current term, with control over whether freqs, positions, offsets or payloads are required. Do not call this when the enum is unpositioned. This method will not return null.NOTE: the returned iterator may return deleted documents, so deleted documents have to be checked on top of the
PostingsEnum
.- Specified by:
postings
in classTermsEnum
- Parameters:
reuse
- pass a prior PostingsEnum for possible reuseflags
- specifies which optional per-document values you require; seePostingsEnum.FREQS
- Throws:
IOException
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impacts
Description copied from class:TermsEnum
Return aImpactsEnum
.- Specified by:
impacts
in classTermsEnum
- Throws:
IOException
- See Also:
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seekExact
Description copied from class:TermsEnum
Expert: Seeks a specific position byTermState
previously obtained fromTermsEnum.termState()
. Callers should maintain theTermState
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 sameTermsEnum
instance.NOTE: Using this method with an incompatible
TermState
might leave thisTermsEnum
in undefined state. On a segment levelTermState
instances are compatible only iff the source and the targetTermsEnum
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 theAttributeSource
's state.AttributeSource
states must be maintained separately if this method is used.- Specified by:
seekExact
in classTermsEnum
- Parameters:
term
- the term the TermState corresponds tostate
- theTermState
- Throws:
IOException
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termState
Description copied from class:TermsEnum
Expert: Returns the TermsEnums internal state to position the TermsEnum without re-seeking the term dictionary.NOTE: A seek by
TermState
might not capture theAttributeSource
's state. Callers must maintain theAttributeSource
states separately- Specified by:
termState
in classTermsEnum
- Throws:
IOException
- See Also:
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ord
Description copied from class:TermsEnum
Returns ordinal position for current term. This is an optional method (the codec may throwUnsupportedOperationException
). Do not call this when the enum is unpositioned.- Specified by:
ord
in classTermsEnum
- Throws:
IOException
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attributes
Description copied from class:TermsEnum
Returns the related attributes.- Specified by:
attributes
in classTermsEnum
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seekExact
Description copied from class:TermsEnum
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 may be substantially faster thanTermsEnum.seekCeil(org.apache.lucene.util.BytesRef)
.- Specified by:
seekExact
in classTermsEnum
- Returns:
- true if the term is found; return false if the enum is unpositioned.
- Throws:
IOException
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seekCeil
Description copied from class:TermsEnum
Seeks to the specified term, if it exists, or to the next (ceiling) term. Returns 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 SeekStatus.END, the enum is unpositioned.- Specified by:
seekCeil
in classTermsEnum
- Throws:
IOException
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seekExact
Description copied from class:TermsEnum
Seeks to the specified term by ordinal (position) as previously returned byTermsEnum.ord()
. The target ord may be before or after the current ord, and must be within bounds.- Specified by:
seekExact
in classTermsEnum
- Throws:
IOException
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term
Description copied from class:TermsEnum
Returns current term. Do not call this when the enum is unpositioned.- Specified by:
term
in classTermsEnum
- Throws:
IOException
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