FunctionQuery (Lucene 7.7.0 API)

java.lang.Object
- org.apache.lucene.search.Query
- - org.apache.lucene.queries.function.FunctionQuery

```
public class FunctionQuery
extends Query
```
Returns a score for each document based on a ValueSource, often some function of the value of a field.

See Also:

ValueSourceScorer

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

Nested Class Summary

Nested Classes
Modifier and Type Class Description

protected class FunctionQuery.AllScorer

protected class FunctionQuery.FunctionWeight

Constructor Summary

Constructors
Constructor Description

FunctionQuery(ValueSource func)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Weight`	`createWeight(IndexSearcher searcher, boolean needsScores, float boost)`
`boolean`	`equals(Object other)`	Returns true if `o` is equal to this.
`ValueSource`	`getValueSource()`
`int`	`hashCode()`
`String`	`toString(String field)`	Prints a user-readable version of this query.

Methods inherited from class org.apache.lucene.search.Query
classHash, rewrite, sameClassAs, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Constructor Detail
  - FunctionQuery
```
public FunctionQuery(ValueSource func)
```
    Parameters:
    
    func - defines the function to be used for scoring
- Method Detail
  - getValueSource
```
public ValueSource getValueSource()
```
    Returns:
    
    The associated ValueSource
  - createWeight
```
public Weight createWeight(IndexSearcher searcher,
                           boolean needsScores,
                           float boost)
                    throws IOException
```
    Overrides:
    
    createWeight in class Query
    
    Throws:
    
    IOException
  - toString
```
public String toString(String field)
```
    Prints a user-readable version of this query.
    
    Specified by:
    
    toString in class Query
  - equals
```
public boolean equals(Object other)
```
    Returns true if o is equal to this.
    
    Specified by:
    
    equals in class Query
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in class Query