ConcatenateGraphFilter (Lucene 10.5.0 common API)
Description: declaration: package: org.apache.lucene.analysis.miscellaneous, class: ConcatenateGraphFilter

Package org.apache.lucene.analysis.miscellaneous

# Class ConcatenateGraphFilter

java.lang.Object
org.apache.lucene.util.AttributeSource
org.apache.lucene.analysis.TokenStream
org.apache.lucene.analysis.miscellaneous.ConcatenateGraphFilter

All Implemented Interfaces:
  `Closeable`, `AutoCloseable`

public final class ConcatenateGraphFilter extends TokenStream
Concatenates/Joins every incoming token with a separator into one output token for every path through the token stream (which is a graph). In simple cases this yields one token, but in the presence of any tokens with a zero positionIncrement (e.g. synonyms) it will be more. This filter uses the token bytes, position increment, and position length of the incoming stream. Other attributes are not used or manipulated.

WARNING: This API is experimental and might change in incompatible ways in the next release.

- ## Nested Class Summary

  Nested Classes
  Modifier and Type
  Class
  Description
  `static interface`
  `ConcatenateGraphFilter.BytesRefBuilderTermAttribute`
  Attribute providing access to the term builder and UTF-16 conversion
  `static final class`
  `ConcatenateGraphFilter.BytesRefBuilderTermAttributeImpl`
  Implementation of `ConcatenateGraphFilter.BytesRefBuilderTermAttribute`

  ## Nested classes/interfaces inherited from class org.apache.lucene.util.AttributeSource

  `AttributeSource.State`

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final int`
  `DEFAULT_MAX_GRAPH_EXPANSIONS`
  `static final boolean`
  `DEFAULT_PRESERVE_POSITION_INCREMENTS`
  `static final boolean`
  `DEFAULT_PRESERVE_SEP`
  `static final Character`
  `DEFAULT_TOKEN_SEPARATOR`
  `static final int`
  `SEP_LABEL`
  Represents the default separator between tokens.

  ### Fields inherited from class org.apache.lucene.analysis.TokenStream

  `DEFAULT_TOKEN_ATTRIBUTE_FACTORY`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ConcatenateGraphFilter(TokenStream inputTokenStream)`
  Creates a token stream to convert `input` to a token stream of accepted strings by its token stream graph.
  `ConcatenateGraphFilter(TokenStream inputTokenStream, boolean preserveSep, boolean preservePositionIncrements, int maxGraphExpansions)`
  Calls `ConcatenateGraphFilter(org.apache.lucene.analysis.TokenStream, java.lang.Character, boolean, int)`
  `ConcatenateGraphFilter(TokenStream inputTokenStream, Character tokenSeparator, boolean preservePositionIncrements, int maxGraphExpansions)`
  Creates a token stream to convert `input` to a token stream of accepted strings by its token stream graph.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `close()`
  `void`
  `end()`
  `boolean`
  `incrementToken()`
  `void`
  `reset()`
  `Automaton`
  `toAutomaton()`
  Converts the tokenStream to an automaton, treating the transition labels as utf-8.
  `Automaton`
  `toAutomaton(boolean unicodeAware)`
  Converts the tokenStream to an automaton.

  ### Methods inherited from class org.apache.lucene.util.AttributeSource

  `addAttribute, addAttributeImpl, captureState, clearAttributes, cloneAttributes, copyTo, endAttributes, equals, getAttribute, getAttributeClassesIterator, getAttributeFactory, getAttributeImplsIterator, hasAttribute, hasAttributes, hashCode, reflectAsString, reflectWith, removeAllAttributes, restoreState, toString`

  ### Methods inherited from class java.lang.Object

  `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### SEP_LABEL

    public static final int SEP_LABEL
    Represents the default separator between tokens.
    See Also:
      - Constant Field Values

  - ### DEFAULT_MAX_GRAPH_EXPANSIONS

    public static final int DEFAULT_MAX_GRAPH_EXPANSIONS
    See Also:
      - Constant Field Values

  - ### DEFAULT_TOKEN_SEPARATOR

    public static final Character DEFAULT_TOKEN_SEPARATOR

  - ### DEFAULT_PRESERVE_SEP

    public static final boolean DEFAULT_PRESERVE_SEP
    See Also:
      - Constant Field Values

  - ### DEFAULT_PRESERVE_POSITION_INCREMENTS

    public static final boolean DEFAULT_PRESERVE_POSITION_INCREMENTS
    See Also:
      - Constant Field Values

- ## Constructor Details

  - ### ConcatenateGraphFilter

    public ConcatenateGraphFilter(TokenStream inputTokenStream)
    Creates a token stream to convert `input` to a token stream of accepted strings by its token stream graph.

    This constructor uses the default settings of the constants in this class.

  - ### ConcatenateGraphFilter

    public ConcatenateGraphFilter(TokenStream inputTokenStream, Character tokenSeparator, boolean preservePositionIncrements, int maxGraphExpansions)
    Creates a token stream to convert `input` to a token stream of accepted strings by its token stream graph.
    Parameters:
      `inputTokenStream` - The input/incoming TokenStream
      `tokenSeparator` - Separator to use for concatenation. Can be null, in this case tokens will be concatenated without any separators.
      `preservePositionIncrements` - Whether to add an empty token for missing positions. The effect is a consecutive `SEP_LABEL`. When false, it's as if there were no missing positions (we pretend the surrounding tokens were adjacent).
      `maxGraphExpansions` - If the tokenStream graph has more than this many possible paths through, then we'll throw `TooComplexToDeterminizeException` to preserve the stability and memory of the machine.
    Throws:
      `TooComplexToDeterminizeException` - if the tokenStream graph has more than `maxGraphExpansions` expansions

  - ### ConcatenateGraphFilter

    public ConcatenateGraphFilter(TokenStream inputTokenStream, boolean preserveSep, boolean preservePositionIncrements, int maxGraphExpansions)
    Calls `ConcatenateGraphFilter(org.apache.lucene.analysis.TokenStream, java.lang.Character, boolean, int)`
    Parameters:
      `preserveSep` - Whether `SEP_LABEL` should separate the input tokens in the concatenated token

- ## Method Details

  - ### reset

    public void reset() throws IOException
    Overrides:
      `reset` in class `TokenStream`
    Throws:
      `IOException`

  - ### incrementToken

    public boolean incrementToken() throws IOException
    Specified by:
      `incrementToken` in class `TokenStream`
    Throws:
      `IOException`

  - ### end

    public void end() throws IOException
    Overrides:
      `end` in class `TokenStream`
    Throws:
      `IOException`

  - ### close

    public void close() throws IOException
    Specified by:
      `close` in interface `AutoCloseable`
    Specified by:
      `close` in interface `Closeable`
    Overrides:
      `close` in class `TokenStream`
    Throws:
      `IOException`

  - ### toAutomaton

    public Automaton toAutomaton() throws IOException
    Converts the tokenStream to an automaton, treating the transition labels as utf-8. Does *not* close it.
    Throws:
      `IOException`

  - ### toAutomaton

    public Automaton toAutomaton(boolean unicodeAware) throws IOException
    Converts the tokenStream to an automaton. Does *not* close it.
    Throws:
      `IOException`