Class PatternReplaceFilter

A TokenFilter which applies a Regex to each token in the stream, replacing match occurances with the specified replacement string.

Note: Depending on the input and the pattern used and the input Lucene.Net.Analysis.TokenStream, this Lucene.Net.Analysis.TokenFilter may produce Lucene.Net.Analysis.Tokens whose text is the empty string.

Inheritance

object

AttributeSource

TokenStream

TokenFilter

PatternReplaceFilter

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.Pattern

Assembly: Lucene.Net.Analysis.Common.dll

Syntax

public sealed class PatternReplaceFilter : TokenFilter, IDisposable

Constructors

PatternReplaceFilter(TokenStream, Regex, string, bool)

Constructs an instance to replace either the first, or all occurances

Declaration

public PatternReplaceFilter(TokenStream @in, Regex pattern, string replacement, bool all)

Parameters

Type	Name	Description
TokenStream	in	the Lucene.Net.Analysis.TokenStream to process
Regex	pattern	the pattern (a Regex object) to apply to each Lucene.Net.Analysis.Token
string	replacement	the "replacement string" to substitute, if null a blank string will be used. Note that this is not the literal string that will be used, '$' and '' have special meaning.
bool	all	if true, all matches will be replaced otherwise just the first match.

See Also

Replace(string, string)

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()

See Also

Regex

Implements

IDisposable

See Also

Regex