Class HunspellStemFilter

Lucene.Net.Analysis.TokenFilter that uses hunspell affix rules and words to stem tokens.
Since hunspell supports a word having multiple stems, this filter can emit multiple tokens for each consumed token

Note: This filter is aware of the Lucene.Net.Analysis.TokenAttributes.IKeywordAttribute. To prevent certain terms from being passed to the stemmer Lucene.Net.Analysis.TokenAttributes.IKeywordAttribute.IsKeyword should be set to true in a previous Lucene.Net.Analysis.TokenStream.

Note: For including the original term as well as the stemmed version, see KeywordRepeatFilterFactory

Note

This API is experimental and might change in incompatible ways in the next release.

Inheritance
object
AttributeSource
TokenStream
TokenFilter
HunspellStemFilter
Implements
Inherited Members
TokenFilter.End()
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.ReflectWith(IAttributeReflector)
AttributeSource.CloneAttributes()
AttributeSource.CopyTo(AttributeSource)
AttributeSource.ToString()
Namespace: Lucene.Net.Analysis.Hunspell
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public sealed class HunspellStemFilter : TokenFilter, IDisposable

Constructors

HunspellStemFilter(TokenStream, Dictionary)

Create a HunspellStemFilter outputting all possible stems.

Declaration
public HunspellStemFilter(TokenStream input, Dictionary dictionary)
Parameters
Type Name Description
TokenStream input
Dictionary dictionary
See Also

HunspellStemFilter(TokenStream, Dictionary, bool)

Create a HunspellStemFilter outputting all possible stems.

Declaration
public HunspellStemFilter(TokenStream input, Dictionary dictionary, bool dedup)
Parameters
Type Name Description
TokenStream input
Dictionary dictionary
bool dedup
See Also

HunspellStemFilter(TokenStream, Dictionary, bool, bool)

Creates a new HunspellStemFilter that will stem tokens from the given Lucene.Net.Analysis.TokenStream using affix rules in the provided Dictionary

Declaration
public HunspellStemFilter(TokenStream input, Dictionary dictionary, bool dedup, bool longestOnly)
Parameters
Type Name Description
TokenStream input

Lucene.Net.Analysis.TokenStream whose tokens will be stemmed
Dictionary dictionary

Hunspell Dictionary containing the affix rules and words that will be used to stem the tokens
bool dedup

remove duplicates
bool longestOnly

true if only the longest term should be output.

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()

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.TokenFilter.Reset()
Remarks

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

Implements