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 classThrown 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 -
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 specifiedreaderwhich share a prefix of lengthprefixLengthwithtermand which have at mostmaxEditsedits. -
Method Summary
Modifier and TypeMethodDescriptionReturns the related attributes.intdocFreq()Returns the number of documents containing the current term.floatgetBoost()Gets the boost of the current termimpacts(int flags) Return aImpactsEnum.next()Increments the iteration to the nextBytesRefin the iterator.longord()Returns ordinal position for current term.postings(PostingsEnum reuse, int flags) GetPostingsEnumfor the current term, with control over whether freqs, positions, offsets or payloads are required.prepareSeekExact(BytesRef text) Seeks to the specified term, if it exists, or to the next (ceiling) term.voidseekExact(long ord) Seeks to the specified term by ordinal (position) as previously returned byTermsEnum.ord().booleanAttempts to seek to the exact term, returning true if the term is found.voidExpert: Seeks a specific position byTermStatepreviously obtained fromTermsEnum.termState().voidsetMaxNonCompetitiveBoost(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.longReturns 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 specifiedreaderwhich share a prefix of lengthprefixLengthwithtermand which have at mostmaxEditsedits.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:BytesRefIteratorIncrements the iteration to the nextBytesRefin the iterator. Returns the resultingBytesRefornullif 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
BytesRefin the iterator ornullif 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:TermsEnumReturns the number of documents containing the current term. Do not call this when the enum is unpositioned.TermsEnum.SeekStatus.END.- Specified by:
docFreqin classTermsEnum- Throws:
IOException
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totalTermFreq
Description copied from class:TermsEnumReturns 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:
totalTermFreqin classTermsEnum- Throws:
IOException
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postings
Description copied from class:TermsEnumGetPostingsEnumfor 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:
postingsin 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:TermsEnumReturn aImpactsEnum.- Specified by:
impactsin classTermsEnum- Throws:
IOException- See Also:
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seekExact
Description copied from class:TermsEnumExpert: Seeks a specific position byTermStatepreviously obtained fromTermsEnum.termState(). Callers should maintain theTermStateto use this method. Low-level implementations may position the TermsEnum without re-seeking the term dictionary.Seeking by
TermStateshould only be used iff the state was obtained from the sameTermsEnuminstance.NOTE: Using this method with an incompatible
TermStatemight leave thisTermsEnumin undefined state. On a segment levelTermStateinstances are compatible only iff the source and the targetTermsEnumoperate on the same field. If operating on segment level, TermState instances must not be used across segments.NOTE: A seek by
TermStatemight not restore theAttributeSource's state.AttributeSourcestates must be maintained separately if this method is used.- Overrides:
seekExactin classBaseTermsEnum- Parameters:
term- the term the TermState corresponds tostate- theTermState- Throws:
IOException
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termState
Description copied from class:TermsEnumExpert: Returns the TermsEnums internal state to position the TermsEnum without re-seeking the term dictionary.NOTE: A seek by
TermStatemight not capture theAttributeSource's state. Callers must maintain theAttributeSourcestates separately- Overrides:
termStatein classBaseTermsEnum- Throws:
IOException- See Also:
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ord
Description copied from class:TermsEnumReturns 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:
ordin classTermsEnum- Throws:
IOException
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attributes
Description copied from class:TermsEnumReturns the related attributes.- Overrides:
attributesin classBaseTermsEnum
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seekExact
Description copied from class:TermsEnumAttempts 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).- Overrides:
seekExactin classBaseTermsEnum- Returns:
- true if the term is found; return false if the enum is unpositioned.
- Throws:
IOException
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prepareSeekExact
Description copied from class:TermsEnumTwo-phaseTermsEnum.seekExact(org.apache.lucene.util.BytesRef). The first phase typically callsIndexInput.prefetch(long, long)on the right range of bytes under the hood, while the second phaseIOBooleanSupplier.get()actually seeks the term within these bytes. This can be used to parallelize I/O across multiple terms by callingTermsEnum.prepareSeekExact(org.apache.lucene.util.BytesRef)on multiple terms enums before callingIOBooleanSupplier.get().NOTE: It is illegal to call other methods on this
TermsEnumafter calling this method untilIOBooleanSupplier.get()is called.NOTE: This may return
nullif thisTermsEnumcan identify that the term may not exist without performing any I/O.NOTE: The returned
IOBooleanSuppliermust be consumed in the same thread.- Overrides:
prepareSeekExactin classBaseTermsEnum- Throws:
IOException
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seekCeil
Description copied from class:TermsEnumSeeks 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:
seekCeilin classTermsEnum- Throws:
IOException
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seekExact
Description copied from class:TermsEnumSeeks 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:
seekExactin classTermsEnum- Throws:
IOException
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term
Description copied from class:TermsEnumReturns current term. Do not call this when the enum is unpositioned.- Specified by:
termin classTermsEnum- Throws:
IOException
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