Class BlendedInfixSuggester

Extension of the AnalyzingInfixSuggester which transforms the weight after search to take into account the position of the searched term into the indexed text. Please note that it increases the number of elements searched and applies the ponderation after. It might be costly for long suggestions.

Note

This API is experimental and might change in incompatible ways in the next release.

Inheritance
object
Lookup
AnalyzingInfixSuggester
BlendedInfixSuggester
Implements
Inherited Members
Namespace: Lucene.Net.Search.Suggest.Analyzing
Assembly: Lucene.Net.Suggest.dll
Syntax
public class BlendedInfixSuggester : AnalyzingInfixSuggester, IDisposable

Constructors

BlendedInfixSuggester(LuceneVersion, Directory, Analyzer)

Create a new instance, loading from a previously built directory, if it exists.

Declaration
public BlendedInfixSuggester(LuceneVersion matchVersion, Directory dir, Analyzer analyzer)
Parameters
Type Name Description
LuceneVersion matchVersion
Directory dir
Analyzer analyzer

BlendedInfixSuggester(LuceneVersion, Directory, Analyzer, Analyzer, int, BlenderType, int)

Create a new instance, loading from a previously built directory, if it exists.

Declaration
public BlendedInfixSuggester(LuceneVersion matchVersion, Directory dir, Analyzer indexAnalyzer, Analyzer queryAnalyzer, int minPrefixChars, BlendedInfixSuggester.BlenderType blenderType, int numFactor)
Parameters
Type Name Description
LuceneVersion matchVersion
Directory dir
Analyzer indexAnalyzer
Analyzer queryAnalyzer
int minPrefixChars
BlendedInfixSuggester.BlenderType blenderType

Type of blending strategy, see BlenderType for more precisions
int numFactor

Factor to multiply the number of searched elements before ponderate
Exceptions
Type Condition
IOException

If there are problems opening the underlying Lucene index.

BlendedInfixSuggester(LuceneVersion, Directory, Analyzer, Analyzer, int, BlenderType, int, bool)

Create a new instance, loading from a previously built directory, if it exists.

Declaration
public BlendedInfixSuggester(LuceneVersion matchVersion, Directory dir, Analyzer indexAnalyzer, Analyzer queryAnalyzer, int minPrefixChars, BlendedInfixSuggester.BlenderType blenderType, int numFactor, bool commitOnBuild)
Parameters
Type Name Description
LuceneVersion matchVersion
Directory dir
Analyzer indexAnalyzer
Analyzer queryAnalyzer
int minPrefixChars
BlendedInfixSuggester.BlenderType blenderType

Type of blending strategy, see BlenderType for more precisions
int numFactor

Factor to multiply the number of searched elements before ponderate
bool commitOnBuild

Call commit after the index has finished building. This would persist the suggester index to disk and future instances of this suggester can use this pre-built dictionary.
Exceptions
Type Condition
IOException

If there are problems opening the underlying Lucene index.

Fields

DEFAULT_NUM_FACTOR

Default factor

Declaration
public static int DEFAULT_NUM_FACTOR
Field Value
Type Description
int

LINEAR_COEF

Coefficient used for linear blending

Declaration
protected static double LINEAR_COEF
Field Value
Type Description
double

Methods

CalculateCoefficient(int)

Calculate the weight coefficient based on the position of the first matching word. Subclass should override it to adapt it to particular needs

Declaration
protected virtual double CalculateCoefficient(int position)
Parameters
Type Name Description
int position

of the first matching word in text
Returns
Type Description
double

the coefficient

CreateResults(IndexSearcher, TopFieldDocs, int, string, bool, ICollection<string>, string)

Create the results based on the search hits. Can be overridden by subclass to add particular behavior (e.g. weight transformation)

Declaration
protected override IList<Lookup.LookupResult> CreateResults(IndexSearcher searcher, TopFieldDocs hits, int num, string key, bool doHighlight, ICollection<string> matchedTokens, string prefixToken)
Parameters
Type Name Description
IndexSearcher searcher
TopFieldDocs hits
int num
string key
bool doHighlight
ICollection<string> matchedTokens
string prefixToken
Returns
Type Description
IList<Lookup.LookupResult>
Overrides
Exceptions
Type Condition
IOException

If there are problems reading fields from the underlying Lucene index.

DoLookup(string, IEnumerable<BytesRef>, bool, int)

Look up a key and return possible completion for this key.

Declaration
public override IList<Lookup.LookupResult> DoLookup(string key, IEnumerable<BytesRef> contexts, bool onlyMorePopular, int num)
Parameters
Type Name Description
string key

lookup key. Depending on the implementation this may be a prefix, misspelling, or even infix.
IEnumerable<BytesRef> contexts

contexts to filter the lookup by, or null if all contexts are allowed; if the suggestion contains any of the contexts, it's a match
bool onlyMorePopular

return only more popular results
int num

maximum number of results to return
Returns
Type Description
IList<Lookup.LookupResult>

a list of possible completions, with their relative weight (e.g. popularity)
Overrides

DoLookup(string, IEnumerable<BytesRef>, int, bool, bool)

Retrieve suggestions, specifying whether all terms must match (allTermsRequired) and whether the hits should be highlighted (doHighlight).

Declaration
public override IList<Lookup.LookupResult> DoLookup(string key, IEnumerable<BytesRef> contexts, int num, bool allTermsRequired, bool doHighlight)
Parameters
Type Name Description
string key
IEnumerable<BytesRef> contexts
int num
bool allTermsRequired
bool doHighlight
Returns
Type Description
IList<Lookup.LookupResult>
Overrides

GetTextFieldType()

Subclass can override this method to change the field type of the text field e.g. to change the index options

Declaration
protected override FieldType GetTextFieldType()
Returns
Type Description
FieldType
Overrides

Implements