Class PatternCaptureGroupTokenFilter

CaptureGroup uses .NET regexes to emit multiple tokens - one for each capture group in one or more patterns.

For example, a pattern like:

"(https?://([a-zA-Z-_0-9.]+))"

when matched against the string "http://www.foo.com/index"; would return the tokens "https://www.foo.com" and "www.foo.com".

If none of the patterns match, or if preserveOriginal is true, the original token will be preserved.

Each pattern is matched as often as it can be, so the pattern "(...)", when matched against "abcdefghi" would produce ["abc","def","ghi"]

A camelCaseFilter could be written as: 

  "([A-Z]{2,})",                                 
  "(?<![A-Z])([A-Z][a-z]+)",                     
  "(?:^|\\b|(?<=[0-9_])|(?<=[A-Z]{2}))([a-z]+)", 
  "([0-9]+)"

plus if Lucene.Net.Analysis.Pattern.PatternCaptureGroupTokenFilter.preserveOriginal is true, it would also return camelCaseFilter

Inheritance
System.Object
AttributeSource
TokenStream
TokenFilter
PatternCaptureGroupTokenFilter
Implements
IDisposable
Inherited Members
Namespace: Lucene.Net.Analysis.Pattern
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public sealed class PatternCaptureGroupTokenFilter : TokenFilter, IDisposable

Constructors

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PatternCaptureGroupTokenFilter(TokenStream, Boolean, Regex[])

Creates a new PatternCaptureGroupTokenFilter

Declaration
public PatternCaptureGroupTokenFilter(TokenStream input, bool preserveOriginal, params Regex[] patterns)
Parameters
Type Name Description
TokenStream input

the input TokenStream

System.Boolean preserveOriginal

set to true to return the original token even if one of the patterns matches

Regex[] patterns

an array of Lucene.Net.Analysis.Pattern objects to match against each token

Methods

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IncrementToken()

Declaration
public override bool IncrementToken()
Returns
Type Description
System.Boolean
Overrides
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Reset()

Declaration
public override void Reset()
Overrides

Implements

IDisposable