Class OpenNLPLemmatizerFilter

Runs OpenNLP dictionary-based and/or MaxEnt lemmatizers.

Both a dictionary-based lemmatizer and a MaxEnt lemmatizer are supported, via the "dictionary" and "lemmatizerModel" params, respectively. If both are configured, the dictionary-based lemmatizer is tried first, and then the MaxEnt lemmatizer is consulted for out-of-vocabulary tokens.

The dictionary file must be encoded as UTF-8, with one entry per line, in the form word[tab]lemma[tab]part-of-speech

Inheritance

object

AttributeSource

TokenStream

TokenFilter

OpenNLPLemmatizerFilter

Implements

IDisposable

Inherited Members

TokenFilter.m_input

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.Equals(object)

AttributeSource.ReflectAsString(bool)

AttributeSource.ReflectWith(IAttributeReflector)

AttributeSource.CloneAttributes()

AttributeSource.CopyTo(AttributeSource)

AttributeSource.ToString()

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Lucene.Net.Analysis.OpenNlp

Assembly: Lucene.Net.Analysis.OpenNLP.dll

Syntax

public class OpenNLPLemmatizerFilter : TokenFilter, IDisposable

Constructors

OpenNLPLemmatizerFilter(TokenStream, NLPLemmatizerOp)

Runs OpenNLP dictionary-based and/or MaxEnt lemmatizers.

Both a dictionary-based lemmatizer and a MaxEnt lemmatizer are supported, via the "dictionary" and "lemmatizerModel" params, respectively. If both are configured, the dictionary-based lemmatizer is tried first, and then the MaxEnt lemmatizer is consulted for out-of-vocabulary tokens.

The dictionary file must be encoded as UTF-8, with one entry per line, in the form word[tab]lemma[tab]part-of-speech

Declaration

public OpenNLPLemmatizerFilter(TokenStream input, NLPLemmatizerOp lemmatizerOp)

Parameters

Type	Name	Description
TokenStream	input
NLPLemmatizerOp	lemmatizerOp

Methods

Dispose(bool)

Releases resources used by the OpenNLPLemmatizerFilter and if overridden in a derived class, optionally releases unmanaged resources.

Declaration

protected override void Dispose(bool disposing)

Parameters

Type	Name	Description
bool	disposing	true to release both managed and unmanaged resources; false to release only unmanaged resources.

Overrides

TokenFilter.Dispose(bool)

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.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

IDisposable