Class GermanNormalizationFilter

Normalizes German characters according to the heuristics of the http://snowball.tartarus.org/algorithms/german2/stemmer.html German2 snowball algorithm. It allows for the fact that ä, ö and ü are sometimes written as ae, oe and ue.

This is useful if you want this normalization without using the German2 stemmer, or perhaps no stemming at all.

Inheritance

object

AttributeSource

TokenStream

TokenFilter

GermanNormalizationFilter

Implements

IDisposable

Inherited Members

TokenFilter.End()

TokenFilter.Reset()

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.De

Assembly: Lucene.Net.Analysis.Common.dll

Syntax

public sealed class GermanNormalizationFilter : TokenFilter, IDisposable

Constructors

GermanNormalizationFilter(TokenStream)

Normalizes German characters according to the heuristics of the http://snowball.tartarus.org/algorithms/german2/stemmer.html German2 snowball algorithm. It allows for the fact that ä, ö and ü are sometimes written as ae, oe and ue.

This is useful if you want this normalization without using the German2 stemmer, or perhaps no stemming at all.

Declaration

public GermanNormalizationFilter(TokenStream input)

Parameters

Type	Name	Description
TokenStream	input

Methods

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 bool IncrementToken()

Returns

Type	Description
bool	false for end of stream; true otherwise

Overrides

Lucene.Net.Analysis.TokenStream.IncrementToken()

Implements

IDisposable