Class ICUCollationAttributeFactory

Converts each token into its ICU4N.Text.CollationKey, and then encodes bytes as an index term.

Inheritance
System.Object
AttributeSource.AttributeFactory
ICUCollationAttributeFactory
Inherited Members
System.Object.Equals(System.Object)
System.Object.Equals(System.Object, System.Object)
System.Object.GetHashCode()
System.Object.GetType()
System.Object.MemberwiseClone()
System.Object.ReferenceEquals(System.Object, System.Object)
System.Object.ToString()
Namespace: Lucene.Net.Collation
Assembly: Lucene.Net.ICU.dll
Syntax
public class ICUCollationAttributeFactory : AttributeSource.AttributeFactory
Remarks

WARNING: Make sure you use exactly the same ICU4N.Text.Collator at index and query time -- ICU4N.Text.CollationKeys are only comparable when produced by the same ICU4N.Text.Collator. ICU4N.Text.RuleBasedCollators are independently versioned, so it is safe to search against stored ICU4N.Text.CollationKeys if the following are exactly the same (best practice is to store this information with the index and check that they remain the same at query time):

  1. Collator version - see ICU4N.Text.Collator Version
  2. The collation strength used - see ICU4N.Text.Collator.Strength

ICU4N.Text.CollationKeys generated by ICU Collators are not compatible with those generated by java.text.Collators. Specifically, if you use ICUCollationAttributeFactory to generate index terms, do not use CollationAttributeFactory on the query side, or vice versa.

ICUCollationAttributeFactory is significantly faster and generates significantly shorter keys than CollationAttributeFactory. See http://site.icu-project.org/charts/collation-icu4j-sun for key generation timing and key length comparisons between ICU4J and java.text.Collator over several languages.

Constructors

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ICUCollationAttributeFactory(Collator)

Create an ICUCollationAttributeFactory, using DEFAULT_ATTRIBUTE_FACTORY as the factory for all other attributes.

Declaration
public ICUCollationAttributeFactory(Collator collator)
Parameters
Type Name Description
ICU4N.Text.Collator collator

ICU4N.Text.CollationKey generator
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ICUCollationAttributeFactory(AttributeSource.AttributeFactory, Collator)

Create an ICUCollationAttributeFactory, using the supplied Attribute Factory as the factory for all other attributes.

Declaration
public ICUCollationAttributeFactory(AttributeSource.AttributeFactory delegate, Collator collator)
Parameters
Type Name Description
AttributeSource.AttributeFactory delegate

Attribute Factory
ICU4N.Text.Collator collator

ICU4N.Text.CollationKey generator

Methods

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CreateAttributeInstance<T>()

Declaration
public override Attribute CreateAttributeInstance<T>()

    where T : IAttribute
Returns
Type Description
Attribute
Type Parameters
Name Description
T
Overrides