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 Fast, general-purpose grammar-based tokenizers. 

The `org.apache.lucene.analysis.standard` package contains three fast grammar-based tokenizers constructed with JFlex:

*   <xref:Lucene.Net.Analysis.Standard.StandardTokenizer>:
        as of Lucene 3.1, implements the Word Break rules from the Unicode Text 
        Segmentation algorithm, as specified in 
        [Unicode Standard Annex #29](http://unicode.org/reports/tr29/).
        Unlike `UAX29URLEmailTokenizer`, URLs and email addresses are
    **not** tokenized as single tokens, but are instead split up into 
        tokens according to the UAX#29 word break rules.

        [StandardAnalyzer](xref:Lucene.Net.Analysis.Standard.StandardAnalyzer) includes
        [StandardTokenizer](xref:Lucene.Net.Analysis.Standard.StandardTokenizer),
        [StandardFilter](xref:Lucene.Net.Analysis.Standard.StandardFilter), 
        [LowerCaseFilter](xref:Lucene.Net.Analysis.Core.LowerCaseFilter)
        and [StopFilter](xref:Lucene.Net.Analysis.Core.StopFilter).
        When the `Version` specified in the constructor is lower than 
    3.1, the [ClassicTokenizer](xref:Lucene.Net.Analysis.Standard.ClassicTokenizer)
        implementation is invoked.
*   [ClassicTokenizer](xref:Lucene.Net.Analysis.Standard.ClassicTokenizer):
        this class was formerly (prior to Lucene 3.1) named 
        `StandardTokenizer`.  (Its tokenization rules are not
        based on the Unicode Text Segmentation algorithm.)
        [ClassicAnalyzer](xref:Lucene.Net.Analysis.Standard.ClassicAnalyzer) includes
        [ClassicTokenizer](xref:Lucene.Net.Analysis.Standard.ClassicTokenizer),
        [StandardFilter](xref:Lucene.Net.Analysis.Standard.StandardFilter), 
        [LowerCaseFilter](xref:Lucene.Net.Analysis.Core.LowerCaseFilter)
        and [StopFilter](xref:Lucene.Net.Analysis.Core.StopFilter).

*   [UAX29URLEmailTokenizer](xref:Lucene.Net.Analysis.Standard.UAX29URLEmailTokenizer):
        implements the Word Break rules from the Unicode Text Segmentation
        algorithm, as specified in 
        [Unicode Standard Annex #29](http://unicode.org/reports/tr29/).
        URLs and email addresses are also tokenized according to the relevant RFCs.

        [UAX29URLEmailAnalyzer](xref:Lucene.Net.Analysis.Standard.UAX29URLEmailAnalyzer) includes
        [UAX29URLEmailTokenizer](xref:Lucene.Net.Analysis.Standard.UAX29URLEmailTokenizer),
        [StandardFilter](xref:Lucene.Net.Analysis.Standard.StandardFilter),
        [LowerCaseFilter](xref:Lucene.Net.Analysis.Core.LowerCaseFilter)
        and [StopFilter](xref:Lucene.Net.Analysis.Core.StopFilter).