Namespace Lucene.Net.Analysis.Core

Basic, general-purpose analysis components.

Classes

KeywordAnalyzer

"Tokenizes" the entire stream as a single token. This is useful for data like zip codes, ids, and some product names.

KeywordTokenizer

Emits the entire input as a single token.

KeywordTokenizerFactory

<fieldType name="text_keyword" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.KeywordTokenizerFactory"/>
  </analyzer>
</fieldType>

LetterTokenizer

A LetterTokenizer is a tokenizer that divides text at non-letters. That's to say, it defines tokens as maximal strings of adjacent letters, as defined by System.Char.IsLetter(System.Char) predicate.

Note: this does a decent job for most European languages, but does a terrible job for some Asian languages, where words are not separated by spaces.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating LetterTokenizer:

As of 3.1, CharTokenizer uses an System.Int32 based API to normalize and detect token characters. See IsTokenChar(Int32) and Normalize(Int32) for details.

LetterTokenizerFactory

Factory for LetterTokenizer.

<fieldType name="text_letter" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.LetterTokenizerFactory"/>
  </analyzer>
</fieldType>

LowerCaseFilter

Normalizes token text to lower case.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating LowerCaseFilter:

As of 3.1, supplementary characters are properly lowercased.

LowerCaseFilterFactory

Factory for LowerCaseFilter.

<fieldType name="text_lwrcase" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.WhitespaceTokenizerFactory"/>
    <filter class="solr.LowerCaseFilterFactory"/>
  </analyzer>
</fieldType>

LowerCaseTokenizer performs the function of LetterTokenizer and LowerCaseFilter together. It divides text at non-letters and converts them to lower case. While it is functionally equivalent to the combination of LetterTokenizer and LowerCaseFilter, there is a performance advantage to doing the two tasks at once, hence this (redundant) implementation.

Note: this does a decent job for most European languages, but does a terrible job for some Asian languages, where words are not separated by spaces.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating LowerCaseTokenizer:

As of 3.1, CharTokenizer uses an int based API to normalize and detect token characters. See IsTokenChar(Int32) and Normalize(Int32) for details.

LowerCaseTokenizerFactory

Factory for LowerCaseTokenizer.

<fieldType name="text_lwrcase" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.LowerCaseTokenizerFactory"/>
  </analyzer>
</fieldType>

SimpleAnalyzer

An Lucene.Net.Analysis.Analyzer that filters LetterTokenizer with LowerCaseFilter

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating CharTokenizer:

As of 3.1, LowerCaseTokenizer uses an int based API to normalize and detect token codepoints. See IsTokenChar(Int32) and Normalize(Int32) for details.

StopAnalyzer

Filters LetterTokenizer with LowerCaseFilter and StopFilter.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating StopAnalyzer:

As of 3.1, StopFilter correctly handles Unicode 4.0 supplementary characters in stopwords
As of 2.9, position increments are preserved

StopFilter

Removes stop words from a token stream.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating StopFilter:

As of 3.1, StopFilter correctly handles Unicode 4.0 supplementary characters in stopwords and position increments are preserved

StopFilterFactory

Factory for StopFilter.

<fieldType name="text_stop" class="solr.TextField" positionIncrementGap="100" autoGeneratePhraseQueries="true">
  <analyzer>
    <tokenizer class="solr.WhitespaceTokenizerFactory"/>
    <filter class="solr.StopFilterFactory" ignoreCase="true"
            words="stopwords.txt" format="wordset" />
  </analyzer>
</fieldType>

All attributes are optional:

ignoreCase defaults to false
words should be the name of a stopwords file to parse, if not specified the factory will use ENGLISH_STOP_WORDS_SET
format defines how the words file will be parsed, and defaults to wordset. If words is not specified, then format must not be specified.

The valid values for the format option are:

wordset - This is the default format, which supports one word per line (including any intra-word whitespace) and allows whole line comments begining with the "#" character. Blank lines are ignored. See GetLines(Stream, Encoding) for details.
snowball - This format allows for multiple words specified on each line, and trailing comments may be specified using the vertical line ("|"). Blank lines are ignored. See GetSnowballWordSet(TextReader, LuceneVersion) for details.

TypeTokenFilter

Removes tokens whose types appear in a set of blocked types from a token stream.

TypeTokenFilterFactory

Factory class for TypeTokenFilter.

<fieldType name="chars" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.StandardTokenizerFactory"/>
    <filter class="solr.TypeTokenFilterFactory" types="stoptypes.txt"
                  useWhitelist="false"/>
  </analyzer>
</fieldType>

UpperCaseFilter

Normalizes token text to UPPER CASE.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating UpperCaseFilter

NOTE: In Unicode, this transformation may lose information when the upper case character represents more than one lower case character. Use this filter when you Require uppercase tokens. Use the LowerCaseFilter for general search matching

UpperCaseFilterFactory

Factory for UpperCaseFilter.

<fieldType name="text_uppercase" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.WhitespaceTokenizerFactory"/>
    <filter class="solr.UpperCaseFilterFactory"/>
  </analyzer>
</fieldType>

NOTE: In Unicode, this transformation may lose information when the upper case character represents more than one lower case character. Use this filter when you require uppercase tokens. Use the LowerCaseFilterFactory for general search matching

WhitespaceAnalyzer

An Lucene.Net.Analysis.Analyzer that uses WhitespaceTokenizer.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating CharTokenizer:

As of 3.1, WhitespaceTokenizer uses an int based API to normalize and detect token codepoints. See IsTokenChar(Int32) and Normalize(Int32) for details.

WhitespaceTokenizer

A WhitespaceTokenizer is a tokenizer that divides text at whitespace. Adjacent sequences of non-Whitespace characters form tokens.

You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating WhitespaceTokenizer:

As of 3.1, CharTokenizer uses an int based API to normalize and detect token characters. See IsTokenChar(Int32) and Normalize(Int32) for details.

WhitespaceTokenizerFactory

Factory for WhitespaceTokenizer.

<fieldType name="text_ws" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.WhitespaceTokenizerFactory"/>
  </analyzer>
</fieldType>