Class UpperCaseFilter
Normalizes token text to UPPER CASE.
You must specify the required Lucene.Net.Util.LuceneVersion compatibility when creating UpperCaseFilter
NOTE: In Unicode, this transformation may lose information when the upper case character represents more than one lower case character. Use this filter when you Require uppercase tokens. Use the LowerCaseFilter for general search matching
Implements
Inherited Members
Namespace: Lucene.Net.Analysis.Core
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public sealed class UpperCaseFilter : TokenFilter, IDisposable
Constructors
UpperCaseFilter(LuceneVersion, TokenStream)
Create a new UpperCaseFilter, that normalizes token text to upper case.
Declaration
public UpperCaseFilter(LuceneVersion matchVersion, TokenStream @in)
Parameters
Type | Name | Description |
---|---|---|
LuceneVersion | matchVersion | See Lucene.Net.Util.LuceneVersion |
TokenStream | in | Lucene.Net.Analysis.TokenStream to filter |
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 sealed bool IncrementToken()
Returns
Type | Description |
---|---|
bool | false for end of stream; true otherwise |