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
Implements
Inherited Members
Namespace: Lucene.Net.Analysis.Pattern
Assembly: Lucene.Net.Analysis.Common.dll
Syntax
public sealed class PatternCaptureGroupTokenFilter : TokenFilter, IDisposableConstructors
| Improve this Doc View SourcePatternCaptureGroupTokenFilter(TokenStream, Boolean, Regex[])
Creates a new PatternCaptureGroupTokenFilter
Declaration
public PatternCaptureGroupTokenFilter(TokenStream input, bool preserveOriginal, params Regex[] patterns)Parameters
| Type | Name | Description |
|---|---|---|
| Lucene.Net.Analysis.TokenStream | input | the input Lucene.Net.Analysis.TokenStream |
| System.Boolean | preserveOriginal | set to true to return the original token even if one of the patterns matches |
| System.Text.RegularExpressions.Regex[] | patterns | an array of Lucene.Net.Analysis.Pattern objects to match against each token |
Methods
| Improve this Doc View SourceIncrementToken()
Declaration
public override bool IncrementToken()Returns
| Type | Description |
|---|---|
| System.Boolean |
Overrides
Reset()
Declaration
public override void Reset()