Class HyphenatedWordsFilter

When the plain text is extracted from documents, we will often have many words hyphenated and broken into two lines. This is often the case with documents where narrow text columns are used, such as newsletters. In order to increase search efficiency, this filter puts hyphenated words broken into two lines back together. This filter should be used on indexing time only. Example field definition in schema.xml:

<fieldtype name="text" class="solr.TextField" positionIncrementGap="100">
 <analyzer type="index">
   <tokenizer class="solr.WhitespaceTokenizerFactory"/>
     <filter class="solr.SynonymFilterFactory" synonyms="index_synonyms.txt" ignoreCase="true" expand="false"/>
     <filter class="solr.StopFilterFactory" ignoreCase="true"/>
     <filter class="solr.HyphenatedWordsFilterFactory"/>
     <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="1" catenateNumbers="1" catenateAll="0"/>
     <filter class="solr.LowerCaseFilterFactory"/>
     <filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
 </analyzer>
 <analyzer type="query">
     <tokenizer class="solr.WhitespaceTokenizerFactory"/>
     <filter class="solr.SynonymFilterFactory" synonyms="synonyms.txt" ignoreCase="true" expand="true"/>
     <filter class="solr.StopFilterFactory" ignoreCase="true"/>
     <filter class="solr.WordDelimiterFilterFactory" generateWordParts="1" generateNumberParts="1" catenateWords="0" catenateNumbers="0" catenateAll="0"/>
     <filter class="solr.LowerCaseFilterFactory"/>
     <filter class="solr.RemoveDuplicatesTokenFilterFactory"/>
 </analyzer>
</fieldtype>
Inheritance
System.Object
AttributeSource
TokenStream
TokenFilter
HyphenatedWordsFilter
Implements
IDisposable
Inherited Members
Namespace: Lucene.Net.Analysis.Miscellaneous
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public sealed class HyphenatedWordsFilter : TokenFilter, IDisposable

Constructors

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HyphenatedWordsFilter(TokenStream)

Creates a new HyphenatedWordsFilter

Declaration
public HyphenatedWordsFilter(TokenStream in)
Parameters
Type Name Description
TokenStream in

TokenStream that will be filtered

Methods

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IncrementToken()

Consumers (i.e., IndexWriter) use this method to advance the stream to the next token. Implementing classes must implement this method and update the appropriate Attributes 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 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 AddAttribute<T>() and GetAttribute<T>(), references to all Attributes 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 IncrementToken().

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

false for end of stream; true otherwise

Overrides
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Reset()

This method is called by a consumer before it begins consumption using 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., Tokenizer will throw on further usage).

Declaration
public override void Reset()
Overrides
Remarks

NOTE: The default implementation chains the call to the input TokenStream, so be sure to call base.Reset() when overriding this method.

Implements

IDisposable