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

object

AttributeSource

TokenStream

Tokenizer

ClassicTokenizer

Implements

IDisposable

Inherited Members

Tokenizer.SetReader(TextReader)

TokenStream.Dispose()

AttributeSource.GetAttributeFactory()

AttributeSource.GetAttributeClassesEnumerator()

AttributeSource.GetAttributeImplsEnumerator()

AttributeSource.AddAttributeImpl(Attribute)

AttributeSource.AddAttribute<T>()

AttributeSource.HasAttributes

AttributeSource.HasAttribute<T>()

AttributeSource.GetAttribute<T>()

AttributeSource.ClearAttributes()

AttributeSource.CaptureState()

AttributeSource.RestoreState(AttributeSource.State)

AttributeSource.GetHashCode()

AttributeSource.Equals(object)

AttributeSource.ReflectAsString(bool)

AttributeSource.ReflectWith(IAttributeReflector)

AttributeSource.CloneAttributes()

AttributeSource.CopyTo(AttributeSource)

AttributeSource.ToString()

object.Equals(object, object)

object.GetType()

object.ReferenceEquals(object, object)

Namespace: Lucene.Net.Analysis.Standard

Assembly: Lucene.Net.Analysis.Common.dll

Syntax

public sealed class ClassicTokenizer : Tokenizer, IDisposable

Constructors

ClassicTokenizer(LuceneVersion, AttributeFactory, TextReader)

Creates a new ClassicTokenizer with a given Lucene.Net.Util.AttributeSource.AttributeFactory

Declaration

public ClassicTokenizer(LuceneVersion matchVersion, AttributeSource.AttributeFactory factory, TextReader input)

Parameters

Type	Name	Description
LuceneVersion	matchVersion
AttributeSource.AttributeFactory	factory
TextReader	input

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
TextReader	input	The input reader See http://issues.apache.org/jira/browse/LUCENE-1068

Fields

ACRONYM

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.

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.

Declaration

public const int ACRONYM = 2

Field Value

Type	Description
int

ACRONYM_DEP

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.

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.

Declaration

public const int ACRONYM_DEP = 8

Field Value

Type	Description
int

ALPHANUM

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.

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.

Declaration

public const int ALPHANUM = 0

Field Value

Type	Description
int

APOSTROPHE

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.

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.

Declaration

public const int APOSTROPHE = 1

Field Value

Type	Description
int

CJ

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.

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.

Declaration

public const int CJ = 7

Field Value

Type	Description
int

COMPANY

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.

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.

Declaration

public const int COMPANY = 3

Field Value

Type	Description
int

EMAIL

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.

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.

Declaration

public const int EMAIL = 4

Field Value

Type	Description
int

HOST

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.

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.

Declaration

public const int HOST = 5

Field Value

Type	Description
int

NUM

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.

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.

Declaration

public const int NUM = 6

Field Value

Type	Description
int

TOKEN_TYPES

String token types that correspond to token type int constants

Declaration

public static readonly string[] TOKEN_TYPES

Field Value

Type	Description
string[]

Properties

MaxTokenLength

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

Declaration

public int MaxTokenLength { get; set; }

Property Value

Type	Description
int

Methods

Dispose(bool)

Releases resources associated with this stream.

If you override this method, always call base.Dispose(disposing), otherwise some internal state will not be correctly reset (e.g., Lucene.Net.Analysis.Tokenizer will throw InvalidOperationException on reuse).

Declaration

protected override void Dispose(bool disposing)

Parameters

Type	Name	Description
bool	disposing

Overrides

Tokenizer.Dispose(bool)

Remarks

NOTE: The default implementation closes the input TextReader, so be sure to call base.Dispose(disposing) when overriding this method.

End()

This method is called by the consumer after the last token has been consumed, after Lucene.Net.Analysis.TokenStream.IncrementToken() returned false (using the new Lucene.Net.Analysis.TokenStream API). Streams implementing the old API should upgrade to use this feature.

This method can be used to perform any end-of-stream operations, such as setting the final offset of a stream. The final offset of a stream might differ from the offset of the last token eg in case one or more whitespaces followed after the last token, but a WhitespaceTokenizer was used.

Additionally any skipped positions (such as those removed by a stopfilter) can be applied to the position increment, or any adjustment of other attributes where the end-of-stream value may be important.

If you override this method, always call base.End();.

Declaration

public override sealed void End()

Overrides

Lucene.Net.Analysis.TokenStream.End()

Exceptions

Type	Condition
IOException	If an I/O error occurs

IncrementToken()

Consumers (i.e., Lucene.Net.Index.IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate Lucene.Net.Util.IAttributes with the attributes of the next token.

The producer must make no assumptions about the attributes after the method has been returned: the caller may arbitrarily change it. If the producer needs to preserve the state for subsequent calls, it can use Lucene.Net.Util.AttributeSource.CaptureState() to create a copy of the current attribute state.

this method is called for every token of a document, so an efficient implementation is crucial for good performance. To avoid calls to Lucene.Net.Util.AttributeSource.AddAttribute<T>() and Lucene.Net.Util.AttributeSource.GetAttribute<T>(), references to all Lucene.Net.Util.IAttributes that this stream uses should be retrieved during instantiation.

To ensure that filters and consumers know which attributes are available, the attributes must be added during instantiation. Filters and consumers are not required to check for availability of attributes in Lucene.Net.Analysis.TokenStream.IncrementToken().

Declaration

public override sealed bool IncrementToken()

Returns

Type	Description
bool	false for end of stream; true otherwise

Overrides

Lucene.Net.Analysis.TokenStream.IncrementToken()

Reset()

This method is called by a consumer before it begins consumption using Lucene.Net.Analysis.TokenStream.IncrementToken().

Resets this stream to a clean state. Stateful implementations must implement this method so that they can be reused, just as if they had been created fresh.

If you override this method, always call base.Reset(), otherwise some internal state will not be correctly reset (e.g., Lucene.Net.Analysis.Tokenizer will throw InvalidOperationException on further usage).

Declaration

public override void Reset()

Overrides

Lucene.Net.Analysis.Tokenizer.Reset()

Implements

IDisposable