Class ICUFoldingFilter

A Lucene.Net.Analysis.TokenFilter that applies search term folding to Unicode text, applying foldings from UTR#30 Character Foldings.

Inheritance

object

AttributeSource

TokenStream

TokenFilter

ICUNormalizer2Filter

ICUFoldingFilter

Implements

IDisposable

Inherited Members

ICUNormalizer2Filter.IncrementToken()

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.Icu

Assembly: Lucene.Net.ICU.dll

Syntax

public sealed class ICUFoldingFilter : ICUNormalizer2Filter, IDisposable

Remarks

This filter applies the following foldings from the report to unicode text:

• Accent removal
• Case folding
• Canonical duplicates folding
• Dashes folding
• Diacritic removal (including stroke, hook, descender)
• Greek letterforms folding
• Han Radical folding
• Hebrew Alternates folding
• Jamo folding
• Letterforms folding
• Math symbol folding
• Multigraph Expansions: All
• Native digit folding
• No-break folding
• Overline folding
• Positional forms folding
• Small forms folding
• Space folding
• Spacing Accents folding
• Subscript folding
• Superscript folding
• Suzhou Numeral folding
• Symbol folding
• Underline folding
• Vertical forms folding
• Width folding

Additionally, Default Ignorables are removed, and text is normalized to NFKC. All foldings, case folding, and normalization mappings are applied recursively to ensure a fully folded and normalized result.

Constructors

ICUFoldingFilter(TokenStream)

Create a new ICUFoldingFilter on the specified input

Declaration

public ICUFoldingFilter(TokenStream input)

Parameters

Type	Name	Description
TokenStream	input

Remarks

This filter applies the following foldings from the report to unicode text:

• Accent removal
• Case folding
• Canonical duplicates folding
• Dashes folding
• Diacritic removal (including stroke, hook, descender)
• Greek letterforms folding
• Han Radical folding
• Hebrew Alternates folding
• Jamo folding
• Letterforms folding
• Math symbol folding
• Multigraph Expansions: All
• Native digit folding
• No-break folding
• Overline folding
• Positional forms folding
• Small forms folding
• Space folding
• Spacing Accents folding
• Subscript folding
• Superscript folding
• Suzhou Numeral folding
• Symbol folding
• Underline folding
• Vertical forms folding
• Width folding

Additionally, Default Ignorables are removed, and text is normalized to NFKC. All foldings, case folding, and normalization mappings are applied recursively to ensure a fully folded and normalized result.

Implements

IDisposable