C# Class Lucene.Net.Search.SortField

Stores information about how to sort documents by terms in an individual field. Fields must be indexed in order to sort by them.

Created: Feb 11, 2004 1:25:29 PM @since lucene 1.4

Show file Open project: apache/lucenenet Class Usage Examples

Public Properties

Property	Type	Description
FIELD_DOC	SortField
FIELD_SCORE	SortField
STRING_FIRST	object
STRING_LAST	object
missingValue	object

Public Methods

Method	Description
Equals ( object o ) : bool	Returns true if `o` is equal to this. If a FieldComparatorSource or {@link FieldCache.Parser} was provided, it must properly implement equals (unless a singleton is always used).
GetComparator ( int numHits, int sortPos ) : FieldComparator	Returns the FieldComparator to use for sorting. @lucene.experimental
GetHashCode ( ) : int	Returns true if `o` is equal to this. If a FieldComparatorSource or {@link FieldCache.Parser} was provided, it must properly implement hashCode (unless a singleton is always used).
NeedsScores ( ) : bool	Whether the relevance score is needed to sort documents.
Rewrite ( IndexSearcher searcher ) : SortField	Rewrites this SortField, returning a new SortField if a change is made. Subclasses should override this define their rewriting behavior when this SortField is of type SortField.Type#REWRITEABLE
SortField ( string field, Lucene.Net.Search.FieldCache parser ) : System	Creates a sort by terms in the given field, parsed to numeric values using a custom IFieldCache.Parser.
SortField ( string field, FieldCache parser, bool reverse ) : System	Creates a sort, possibly in reverse, by terms in the given field, parsed to numeric values using a custom IFieldCache.Parser.
SortField ( string field, FieldComparatorSource comparator ) : System	Creates a sort with a custom comparison function.
SortField ( string field, FieldComparatorSource comparator, bool reverse ) : System	Creates a sort, possibly in reverse, with a custom comparison function.
SortField ( string field, Type_e type ) : System	Creates a sort by terms in the given field with the type of term values explicitly given.
SortField ( string field, Type_e type, bool reverse ) : System	Creates a sort, possibly in reverse, by terms in the given field with the type of term values explicitly given.
ToString ( ) : string

Private Methods

Method	Description
InitFieldType ( string field, Type_e type ) : void

Method Details

Equals() public method

Returns true if o is equal to this. If a FieldComparatorSource or {@link FieldCache.Parser} was provided, it must properly implement equals (unless a singleton is always used).

public Equals ( object o ) : bool
o	object
return	bool

GetComparator() public method

Returns the FieldComparator to use for sorting. @lucene.experimental

public GetComparator ( int numHits, int sortPos ) : FieldComparator
numHits	int	number of top hits the queue will store
sortPos	int	position of this SortField within {@link /// Sort}. The comparator is primary if sortPos==0, /// secondary if sortPos==1, etc. Some comparators can /// optimize themselves when they are the primary sort.
return	FieldComparator

GetHashCode() public method

Returns true if o is equal to this. If a FieldComparatorSource or {@link FieldCache.Parser} was provided, it must properly implement hashCode (unless a singleton is always used).

public GetHashCode ( ) : int
return	int

NeedsScores() public method

Whether the relevance score is needed to sort documents.

public NeedsScores ( ) : bool
return	bool

Rewrite() public method

Rewrites this SortField, returning a new SortField if a change is made. Subclasses should override this define their rewriting behavior when this SortField is of type SortField.Type#REWRITEABLE

Can be thrown by the rewriting /// @lucene.experimental

public Rewrite ( IndexSearcher searcher ) : SortField
searcher	IndexSearcher	IndexSearcher to use during rewriting
return	SortField

SortField() public method

Creates a sort by terms in the given field, parsed to numeric values using a custom IFieldCache.Parser.

if the parser fails to /// subclass an existing numeric parser, or field is null

public SortField ( string field, Lucene.Net.Search.FieldCache parser ) : System
field	string	Name of field to sort by. Must not be null.
parser	Lucene.Net.Search.FieldCache	Instance of a , /// which must subclass one of the existing numeric /// parsers from . Sort type is inferred /// by testing which numeric parser the parser subclasses.
return	System

SortField() public method

Creates a sort, possibly in reverse, by terms in the given field, parsed to numeric values using a custom IFieldCache.Parser.

if the parser fails to /// subclass an existing numeric parser, or field is null

public SortField ( string field, FieldCache parser, bool reverse ) : System
field	string	Name of field to sort by. Must not be null.
parser	FieldCache	Instance of a , /// which must subclass one of the existing numeric /// parsers from . Sort type is inferred /// by testing which numeric parser the parser subclasses.
reverse	bool	True if natural order should be reversed.
return	System

SortField() public method

Creates a sort with a custom comparison function.

public SortField ( string field, FieldComparatorSource comparator ) : System
field	string	Name of field to sort by; cannot be `null`.
comparator	FieldComparatorSource	Returns a comparator for sorting hits.
return	System

SortField() public method

Creates a sort, possibly in reverse, with a custom comparison function.

public SortField ( string field, FieldComparatorSource comparator, bool reverse ) : System
field	string	Name of field to sort by; cannot be `null`.
comparator	FieldComparatorSource	Returns a comparator for sorting hits.
reverse	bool	True if natural order should be reversed.
return	System

SortField() public method

Creates a sort by terms in the given field with the type of term values explicitly given.

public SortField ( string field, Type_e type ) : System
field	string	Name of field to sort by. Can be `null` if /// `type` is SCORE or DOC.
type	Type_e	Type of values in the terms.
return	System

SortField() public method

Creates a sort, possibly in reverse, by terms in the given field with the type of term values explicitly given.

public SortField ( string field, Type_e type, bool reverse ) : System
field	string	Name of field to sort by. Can be `null` if /// `type` is SCORE or DOC.
type	Type_e	Type of values in the terms.
reverse	bool	True if natural order should be reversed.
return	System

ToString() public method

public ToString ( ) : string
return	string

Property Details

FIELD_DOC public static property

Represents sorting by document number (index order).

public static SortField,Lucene.Net.Search FIELD_DOC
return	SortField

FIELD_SCORE public static property

Represents sorting by document score (relevance).

public static SortField,Lucene.Net.Search FIELD_SCORE
return	SortField

STRING_FIRST public static property

Pass this to #setMissingValue to have missing string values sort first.

public static object STRING_FIRST
return	object

STRING_LAST public static property

Pass this to #setMissingValue to have missing string values sort last.

public static object STRING_LAST
return	object

missingValue public property

public object missingValue
return	object