Class ClassicTokenizer

A grammar-based tokenizer constructed with JFlex (and then ported to .NET)

This should be a good tokenizer for most European-language documents:

  • Splits words at punctuation characters, removing punctuation. However, a dot that's not followed by whitespace is considered part of a token.
  • Splits words at hyphens, unless there's a number in the token, in which case the whole token is interpreted as a product number and is not split.
  • Recognizes email addresses and internet hostnames as one token.

Many applications have specific tokenizer needs. If this tokenizer does not suit your application, please consider copying this source code directory to your project and maintaining your own grammar-based tokenizer. ClassicTokenizer was named StandardTokenizer in Lucene versions prior to 3.1. As of 3.1, StandardTokenizer implements Unicode text segmentation, as specified by UAX#29.

Inheritance
System.Object
AttributeSource
TokenStream
Tokenizer
ClassicTokenizer
Implements
System.IDisposable
Inherited Members
System.Object.Equals(System.Object, System.Object)
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
Namespace: Lucene.Net.Analysis.Standard
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public sealed class ClassicTokenizer : Tokenizer, IDisposable

Constructors

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ClassicTokenizer(LuceneVersion, AttributeSource.AttributeFactory, TextReader)

Creates a new ClassicTokenizer with a given AttributeSource.AttributeFactory

Declaration
public ClassicTokenizer(LuceneVersion matchVersion, AttributeSource.AttributeFactory factory, TextReader input)
Parameters
Type Name Description
LuceneVersion matchVersion
AttributeSource.AttributeFactory factory
System.IO.TextReader input
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ClassicTokenizer(LuceneVersion, TextReader)

Creates a new instance of the ClassicTokenizer. Attaches the input to the newly created JFlex scanner.

Declaration
public ClassicTokenizer(LuceneVersion matchVersion, TextReader input)
Parameters
Type Name Description
LuceneVersion matchVersion

lucene compatibility version

System.IO.TextReader input

The input reader

See http://issues.apache.org/jira/browse/LUCENE-1068

Fields

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ACRONYM

Declaration
public const int ACRONYM = 2
Field Value
Type Description
System.Int32
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ACRONYM_DEP

Declaration
public const int ACRONYM_DEP = 8
Field Value
Type Description
System.Int32
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ALPHANUM

Declaration
public const int ALPHANUM = 0
Field Value
Type Description
System.Int32
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APOSTROPHE

Declaration
public const int APOSTROPHE = 1
Field Value
Type Description
System.Int32
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CJ

Declaration
public const int CJ = 7
Field Value
Type Description
System.Int32
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COMPANY

Declaration
public const int COMPANY = 3
Field Value
Type Description
System.Int32
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EMAIL

Declaration
public const int EMAIL = 4
Field Value
Type Description
System.Int32
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HOST

Declaration
public const int HOST = 5
Field Value
Type Description
System.Int32
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NUM

Declaration
public const int NUM = 6
Field Value
Type Description
System.Int32
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TOKEN_TYPES

String token types that correspond to token type int constants

Declaration
public static readonly string[] TOKEN_TYPES
Field Value
Type Description
System.String[]

Properties

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MaxTokenLength

Set the max allowed token length. Any token longer than this is skipped.

Declaration
public int MaxTokenLength { get; set; }
Property Value
Type Description
System.Int32

Methods

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Dispose(Boolean)

Declaration
protected override void Dispose(bool disposing)
Parameters
Type Name Description
System.Boolean disposing
Overrides
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End()

Declaration
public override sealed void End()
Overrides
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IncrementToken()

Declaration
public override sealed bool IncrementToken()
Returns
Type Description
System.Boolean
Overrides
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Reset()

Declaration
public override void Reset()
Overrides

Implements

System.IDisposable