Interface QueryEvaluationStep
-
- All Known Subinterfaces:
SliceQueryEvaluationStep
- All Known Implementing Classes:
BindingSetAssignmentQueryEvaluationStep,ExtensionQueryEvaluationStep,FedXZeroLengthPathEvaluationStep,IntersectionQueryEvaluationStep,JoinQueryEvaluationStep,LeftJoinQueryEvaluationStep,MinusQueryEvaluationStep,OrderQueryEvaluationStep,ProjectionQueryEvaluationStep,RdfStarQueryEvaluationStep,ReificationRdfStarQueryEvaluationStep,ServiceQueryEvaluationStep,SliceQueryEvaluationStep.OffSetAndLimitQueryEvaluationStep,SliceQueryEvaluationStep.OnlyLimitQueryEvaluationStep,SliceQueryEvaluationStep.OnlyOffsetQueryEvaluationStep,StatementPatternQueryEvaluationStep,UnionQueryEvaluationStep,ZeroLengthPathEvaluationStep
- Functional Interface:
- This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface QueryEvaluationStep
A Step that may need to be executed in a EvaluationStrategy. The evaluate method should do the minimal work required to evaluate given the bindings. As much as possible should be pre-computed (e.g. resolving constant values)
-
-
Nested Class Summary
Nested Classes Modifier and Type Interface Description static classQueryEvaluationStep.DelayedEvaluationIterationDeprecated, for removal: This API element is subject to removal in a future version.
-
Field Summary
Fields Modifier and Type Field Description static QueryEvaluationStepEMPTYstatic EmptyIteration<BindingSet,QueryEvaluationException>EMPTY_ITERATION
-
Method Summary
All Methods Static Methods Instance Methods Abstract Methods Modifier and Type Method Description static QueryEvaluationStepempty()CloseableIteration<BindingSet,QueryEvaluationException>evaluate(BindingSet bindings)static QueryEvaluationStepminimal(EvaluationStrategy strategy, TupleExpr expr)A fall back implementation that wraps a pre-existing evaluate method on a strategystatic QueryEvaluationStepwrap(QueryEvaluationStep qes, Function<CloseableIteration<BindingSet,QueryEvaluationException>,CloseableIteration<BindingSet,QueryEvaluationException>> wrap)Wrap an QueryEvalationStep: where we apply a function on every evaluation result of the wrapped EvaluationStep.
-
-
-
Field Detail
-
EMPTY_ITERATION
static final EmptyIteration<BindingSet,QueryEvaluationException> EMPTY_ITERATION
-
EMPTY
static final QueryEvaluationStep EMPTY
-
-
Method Detail
-
evaluate
CloseableIteration<BindingSet,QueryEvaluationException> evaluate(BindingSet bindings)
-
minimal
static QueryEvaluationStep minimal(EvaluationStrategy strategy, TupleExpr expr)
A fall back implementation that wraps a pre-existing evaluate method on a strategy- Parameters:
strategy- that can evaluate the tuple expr.expr- that is going to be evaluated- Returns:
- a thin wrapper arround the evaluation call.
-
empty
static QueryEvaluationStep empty()
-
wrap
static QueryEvaluationStep wrap(QueryEvaluationStep qes, Function<CloseableIteration<BindingSet,QueryEvaluationException>,CloseableIteration<BindingSet,QueryEvaluationException>> wrap)
Wrap an QueryEvalationStep: where we apply a function on every evaluation result of the wrapped EvaluationStep. Useful to add a timing function- Parameters:
qes- an QueryEvaluationStep that needs to return modified evaluation resultswrap- the function that will do the modification- Returns:
- a new evaluation step that executes wrap on the inner qes.
-
-