org.apache.flink.util

Interface Visitor<T extends Visitable<T>>

All Known Implementing Classes:

BinaryUnionReplacer, BranchesVisitor, GraphCreatingVisitor, IdAndEstimatesVisitor, InterestingPropertyVisitor, JobGraphGenerator, PlanFinalizer, RangePartitionRewriter, StaticDynamicPathIdentifier, StepFunctionValidator, UnionParallelismAndForwardEnforcer

@Internal
public interface Visitor<T extends Visitable<T>>

A visitor encapsulates functionality that is applied to each node in the process of a traversal of a tree or DAG.

Method Summary

Modifier and Type	Method and Description
void	postVisit(T visitable) Method that is invoked after all child nodes or descendant nodes were visited.
boolean	preVisit(T visitable) Method that is invoked on the visit before visiting and child nodes or descendant nodes.

Method Detail

preVisit

boolean preVisit(T visitable)

Method that is invoked on the visit before visiting and child nodes or descendant nodes.

Returns:

True, if the traversal should continue, false otherwise.

postVisit

void postVisit(T visitable)

Method that is invoked after all child nodes or descendant nodes were visited.