QueryValueEvaluationStep (Eclipse RDF4J 4.3.2)

All Known Implementing Classes:

AndValueEvaluationStep, CompareAllQueryValueEvaluationStep, CompareAnyValueEvaluationStep, ExistsQueryValueEvaluationStep, IfValueEvaluationStep, InValueEvaluationStep, ListMemberValueOperationStep, OrValueEvaluationStep, QueryValueEvaluationStep.ApplyFunctionForEachBinding, QueryValueEvaluationStep.ConstantQueryValueEvaluationStep, QueryValueEvaluationStep.Fail, QueryValueEvaluationStep.Minimal, ValueExprTripleRefEvaluationStep
```
public interface QueryValueEvaluationStep
```
A step in the query evaluation that works on ValueExpresions.

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static class`	`QueryValueEvaluationStep.ApplyFunctionForEachBinding`	A minimal implementation that falls calls a function that should return a value per passed in bindingsets.
`static class`	`QueryValueEvaluationStep.ConstantQueryValueEvaluationStep`	A QueryValueEvalationStep that will return the same constant value throughout the query execution.
`static class`	`QueryValueEvaluationStep.Fail`	A minimal implementation that falls is known to throw an ValueExprEvaluationException.
`static class`	`QueryValueEvaluationStep.Minimal`	A minimal implementation that falls back to calling evaluate in the strategy.

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`Value`	`evaluate(BindingSet bindings)`
`default boolean`	`isConstant()`	If an value expression results in a constant then it may be executed once per query invocation.

- Method Detail
  - evaluate
```
Value evaluate(BindingSet bindings)
        throws QueryEvaluationException
```
    Throws:
    
    QueryEvaluationException
  - isConstant
```
default boolean isConstant()
```
    If an value expression results in a constant then it may be executed once per query invocation. This can reduce computation time significantly.
    
    Returns:
    
    if this ValueExpresionStep will always return the same value