Package org.apache.lucene.search

Class FuzzyTermsEnum

java.lang.Object
org.apache.lucene.index.TermsEnum
org.apache.lucene.search.FuzzyTermsEnum
All Implemented Interfaces:
BytesRefIterator
public final class FuzzyTermsEnum extends TermsEnum
Subclass of TermsEnum for enumerating all terms that are similar to the specified filter term.

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.

  • Constructor Details

    • FuzzyTermsEnum

      public FuzzyTermsEnum(Terms terms, Term term, int maxEdits, int prefixLength, boolean transpositions) throws IOException
      Constructor for enumeration of all terms from specified reader which share a prefix of length prefixLength with term and which have at most maxEdits 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 prefix
      transpositions - whether transpositions should count as a single edit
      Throws:
      IOException - if there is a low-level IO error

  • Method Details

    • 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

      public BytesRef next() throws IOException
      Description copied from interface: BytesRefIterator
      Increments the iteration to the next BytesRef in the iterator. Returns the resulting BytesRef or null 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 or null if the end of the iterator is reached.
      Throws:
      IOException - If there is a low-level I/O error.

    • docFreq

      public int docFreq() throws IOException
      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 class TermsEnum
      Throws:
      IOException

    • totalTermFreq

      public long totalTermFreq() throws IOException
      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 class TermsEnum
      Throws:
      IOException

    • postings

      public PostingsEnum postings(PostingsEnum reuse, int flags) throws IOException
      Description copied from class: TermsEnum
      Get PostingsEnum 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 class TermsEnum
      Parameters:
      reuse - pass a prior PostingsEnum for possible reuse
      flags - specifies which optional per-document values you require; see PostingsEnum.FREQS
      Throws:
      IOException

    • impacts

      public ImpactsEnum impacts(int flags) throws IOException
      Description copied from class: TermsEnum
      Return a ImpactsEnum.
      Specified by:
      impacts in class TermsEnum
      Throws:
      IOException
      See Also:

    • seekExact

      public void seekExact(BytesRef term, TermState state) throws IOException
      Description copied from class: TermsEnum
      Expert: Seeks a specific position by TermState previously obtained from TermsEnum.termState(). 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.

      Specified by:
      seekExact in class TermsEnum
      Parameters:
      term - the term the TermState corresponds to
      state - the TermState
      Throws:
      IOException

    • termState

      public TermState termState() throws IOException
      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 the AttributeSource's state. Callers must maintain the AttributeSource states separately

      Specified by:
      termState in class TermsEnum
      Throws:
      IOException
      See Also:

    • ord

      public long ord() throws IOException
      Description copied from class: TermsEnum
      Returns ordinal position for current term. This is an optional method (the codec may throw UnsupportedOperationException). Do not call this when the enum is unpositioned.
      Specified by:
      ord in class TermsEnum
      Throws:
      IOException

    • attributes

      public AttributeSource attributes()
      Description copied from class: TermsEnum
      Returns the related attributes.
      Specified by:
      attributes in class TermsEnum

    • seekExact

      public boolean seekExact(BytesRef text) throws IOException
      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 than TermsEnum.seekCeil(org.apache.lucene.util.BytesRef).
      Specified by:
      seekExact in class TermsEnum
      Returns:
      true if the term is found; return false if the enum is unpositioned.
      Throws:
      IOException

    • seekCeil

      public TermsEnum.SeekStatus seekCeil(BytesRef text) throws IOException
      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 class TermsEnum
      Throws:
      IOException

    • seekExact

      public void seekExact(long ord) throws IOException
      Description copied from class: TermsEnum
      Seeks to the specified term by ordinal (position) as previously returned by TermsEnum.ord(). The target ord may be before or after the current ord, and must be within bounds.
      Specified by:
      seekExact in class TermsEnum
      Throws:
      IOException

    • term

      public BytesRef term() throws IOException
      Description copied from class: TermsEnum
      Returns current term. Do not call this when the enum is unpositioned.
      Specified by:
      term in class TermsEnum
      Throws:
      IOException