Class PatternTokenizerFactory

Factory for PatternTokenizer. This tokenizer uses regex pattern matching to construct distinct tokens for the input stream. It takes two arguments: "pattern" and "group".

  • "pattern" is the regular expression.
  • "group" says which group to extract into tokens.

group=-1 (the default) is equivalent to "split". In this case, the tokens will be equivalent to the output from (without empty tokens): System.Text.RegularExpressions.Regex.Replace(System.String,System.String)

Using group >= 0 selects the matching group as the token. For example, if you have:

    pattern = \'([^\']+)\'
    group = 0
    input = aaa 'bbb' 'ccc'

the output will be two tokens: 'bbb' and 'ccc' (including the ' marks). With the same input but using group=1, the output would be: bbb and ccc (no ' marks)

NOTE: This Tokenizer does not output tokens that are of zero length.

<fieldType name="text_ptn" class="solr.TextField" positionIncrementGap="100">
  <analyzer>
    <tokenizer class="solr.PatternTokenizerFactory" pattern="\'([^\']+)\'" group="1"/>
  </analyzer>
</fieldType>

@since solr1.2

Inheritance
System.Object
AbstractAnalysisFactory
TokenizerFactory
PatternTokenizerFactory
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Lucene.Net.Analysis.Pattern
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public class PatternTokenizerFactory : TokenizerFactory

Constructors

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PatternTokenizerFactory(IDictionary<String, String>)

Creates a new PatternTokenizerFactory

Declaration
public PatternTokenizerFactory(IDictionary<string, string> args)
Parameters
Type Name Description
System.Collections.Generic.IDictionary<System.String, System.String> args

Fields

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GROUP

Declaration
public const string GROUP = "group"
Field Value
Type Description
System.String
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m_group

Declaration
protected readonly int m_group
Field Value
Type Description
System.Int32
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m_pattern

Declaration
protected readonly Regex m_pattern
Field Value
Type Description
System.Text.RegularExpressions.Regex
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PATTERN

Declaration
public const string PATTERN = "pattern"
Field Value
Type Description
System.String

Methods

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Create(AttributeSource.AttributeFactory, TextReader)

Split the input using configured pattern

Declaration
public override Tokenizer Create(AttributeSource.AttributeFactory factory, TextReader input)
Parameters
Type Name Description
Lucene.Net.Util.AttributeSource.AttributeFactory factory
System.IO.TextReader input
Returns
Type Description
Lucene.Net.Analysis.Tokenizer
Overrides

See Also