Examples of org.apache.lucene.analysis.synonym.SynonymFilter

Package org.apache.lucene.analysis.synonym

Examples of org.apache.lucene.analysis.synonym.SynonymFilter

org.apache.lucene.analysis.synonym.SynonymFilter
Matches single or multi word synonyms in a token stream. This token stream cannot properly handle position increments != 1, ie, you should place this filter before filtering out stop words.
Note that with the current implementation, parsing is greedy, so whenever multiple parses would apply, the rule starting the earliest and parsing the most tokens wins. For example if you have these rules:
```
 a -> x a b -> y b c d -> z 
```
Then input a b c d e parses to y b c d, ie the 2nd rule "wins" because it started earliest and matched the most input tokens of other rules starting at that point.

A future improvement to this filter could allow non-greedy parsing, such that the 3rd rule would win, and also separately allow multiple parses, such that all 3 rules would match, perhaps even on a rule by rule basis.

NOTE: when a match occurs, the output tokens associated with the matching rule are "stacked" on top of the input stream (if the rule had keepOrig=true) and also on top of another matched rule's output tokens. This is not a correct solution, as really the output should be an arbitrary graph/lattice. For example, with the above match, you would expect an exact PhraseQuery "y b c" to match the parsed tokens, but it will fail to do so. This limitation is necessary because Lucene's TokenStream (and index) cannot yet represent an arbitrary graph.

NOTE: If multiple incoming tokens arrive on the same position, only the first token at that position is used for parsing. Subsequent tokens simply pass through and are not parsed. A future improvement would be to allow these tokens to also be matched.

  private boolean ignoreCase;
  
  public TokenStream create(TokenStream input) {
    // if the fst is null, it means there's actually no synonyms... just return the original stream
    // as there is nothing to do here.
    return map.fst == null ? input : new SynonymFilter(input, map, ignoreCase);
  }

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  @Override
  public TokenStream create(TokenStream input) {
    // if the fst is null, it means there's actually no synonyms... just return the original stream
    // as there is nothing to do here.
    return map.fst == null ? input : new SynonymFilter(input, map, ignoreCase);
  }

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    SynonymMap.Builder.join(new String[] { "and", "indubitably", "single", "only" }, multiWordCharsRef);
    builder.add(new CharsRef("one"), multiWordCharsRef, true);
    SynonymMap.Builder.join(new String[]{"dopple", "ganger"}, multiWordCharsRef);
    builder.add(new CharsRef("two"), multiWordCharsRef, true);
    SynonymMap synonymMap = builder.build();
    TokenStream stream = new SynonymFilter(tokenizer, synonymMap, true);
    stream = new LimitTokenPositionFilter(stream, 3); // consumeAllTokens defaults to false
    
    // "only", the 4th word of multi-word synonym "and indubitably single only" is not emitted, since its position is greater than 3.
    assertTokenStreamContents(stream, 
        new String[] { "one", "first", "alpha", "beguine", "and", "two", "indubitably", "dopple", "three", "single", "ganger" },

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      final Analyzer analyzer = new Analyzer() {
        @Override
        protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
          Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.SIMPLE, true);
          TokenStream stream = new SynonymFilter(tokenizer, map, ignoreCase);
          return new TokenStreamComponents(tokenizer, new RemoveDuplicatesTokenFilter(stream));
        }
      };


      checkRandomData(random(), analyzer, 200);

View Full Code Here

  
  @Override
  public TokenStream create(TokenStream input) {
    // if the fst is null, it means there's actually no synonyms... just return the original stream
    // as there is nothing to do here.
    return map.fst == null ? input : new SynonymFilter(input, map, ignoreCase);
  }

View Full Code Here

        synonymMap = new SynonymMap(ignoreCase);
        parseRules(rules, synonymMap, "=>", ",", expand, tokenizerFactory);
    }


    @Override public TokenStream create(TokenStream tokenStream) {
        return new SynonymFilter(tokenStream, synonymMap);
    }

View Full Code Here

  
  @Override
  public TokenStream create(TokenStream input) {
    // if the fst is null, it means there's actually no synonyms... just return the original stream
    // as there is nothing to do here.
    return map.fst == null ? input : new SynonymFilter(input, map, ignoreCase);
  }

View Full Code Here

  
  @Override
  public TokenStream create(TokenStream input) {
    // if the fst is null, it means there's actually no synonyms... just return the original stream
    // as there is nothing to do here.
    return map.fst == null ? input : new SynonymFilter(input, map, ignoreCase);
  }

View Full Code Here

    @Override
    protected TokenStreamComponents createComponents(final String fieldName, final Reader reader) {
        final HebrewTokenizer src = new HebrewTokenizer(reader);
        TokenStream tok = new NiqqudFilter(src);
        tok = new LowerCaseFilter(matchVersion, tok);
        tok = new SynonymFilter(tok, acronymMergingMap, false);
        if (commonWords != null && commonWords.size() > 0)
            tok = new CommonGramsFilter(matchVersion, tok, commonWords, false);
        if ((suffixByTokenType != null) && (suffixByTokenType.size() > 0))
            tok = new AddSuffixFilter(tok, suffixByTokenType);
        return new TokenStreamComponents(src, tok) {

View Full Code Here

      
      final Analyzer analyzer = new Analyzer() {
        @Override
        protected TokenStreamComponents createComponents(String fieldName, Reader reader) {
          Tokenizer tokenizer = new MockTokenizer(reader, MockTokenizer.SIMPLE, true);
          TokenStream stream = new SynonymFilter(tokenizer, map, ignoreCase);
          return new TokenStreamComponents(tokenizer, new RemoveDuplicatesTokenFilter(stream));
        }
      };


      checkRandomData(random(), analyzer, 200);

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org.apache.lucene.analysis.hebrew.SimpleAnalyzer

org.apache.lucene.analysis.miscellaneous.TestLimitTokenPositionFilter

org.apache.lucene.analysis.miscellaneous.TestRemoveDuplicatesTokenFilter

org.apache.lucene.analysis.synonym.FSTSynonymFilterFactory

org.apache.lucene.analysis.Token

org.apache.lucene.analysis.tokenattributes.CharTermAttribute

org.apache.lucene.analysis.tokenattributes.OffsetAttribute

org.apache.lucene.analysis.tokenattributes.PositionIncrementAttribute

org.apache.lucene.util.AttributeSource

org.apache.lucene.util.BytesRef

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