lucene::analysis::Analyzer Class Reference
An Analyzer builds TokenStreams, which analyze text. More...
#include <AnalysisHeader.h>
Public Member Functions | |
| virtual TokenStream * | tokenStream (const TCHAR *fieldName, lucene::util::Reader *reader)=0 |
| Creates a TokenStream which tokenizes all the text in the provided Reader. | |
| virtual | ~Analyzer () |
| virtual int32_t | getPositionIncrementGap (const TCHAR *fieldName) |
| Invoked before indexing a Field instance if terms have already been added to that field. | |
Detailed Description
An Analyzer builds TokenStreams, which analyze text.It thus represents a policy for extracting index terms from text.
Typical implementations first build a Tokenizer, which breaks the stream of characters from the Reader into raw Tokens. One or more TokenFilters may then be applied to the output of the Tokenizer.
WARNING: You must override one of the methods defined by this class in your subclass or the Analyzer will enter an infinite loop.
Constructor & Destructor Documentation
| virtual lucene::analysis::Analyzer::~Analyzer | ( | ) | [inline, virtual] |
Member Function Documentation
| virtual TokenStream* lucene::analysis::Analyzer::tokenStream | ( | const TCHAR * | fieldName, | |
| lucene::util::Reader * | reader | |||
| ) | [pure virtual] |
Creates a TokenStream which tokenizes all the text in the provided Reader.
Default implementation forwards to tokenStream(Reader) for compatibility with older version. Override to allow Analyzer to choose strategy based on document and/or field. Must be able to handle null field name for backward compatibility.
Implemented in lucene::analysis::WhitespaceAnalyzer, lucene::analysis::SimpleAnalyzer, lucene::analysis::StopAnalyzer, lucene::analysis::PerFieldAnalyzerWrapper, lucene::analysis::KeywordAnalyzer, and lucene::analysis::standard::StandardAnalyzer.
| virtual int32_t lucene::analysis::Analyzer::getPositionIncrementGap | ( | const TCHAR * | fieldName | ) | [virtual] |
Invoked before indexing a Field instance if terms have already been added to that field.
This allows custom analyzers to place an automatic position increment gap between Field instances using the same field name. The default value position increment gap is 0. With a 0 position increment gap and the typical default token position increment of 1, all terms in a field, including across Field instances, are in successive positions, allowing exact PhraseQuery matches, for instance, across Field instance boundaries.
- Parameters:
-
fieldName Field name being indexed.
- Returns:
- position increment gap, added to the next token emitted from tokenStream(TCHAR*, Reader*)
The documentation for this class was generated from the following file: