Package org.apache.calcite.rel

Class RelVisitor

java.lang.Object

org.apache.calcite.rel.RelVisitor

Direct Known Subclasses:

Nodes.CoreCompiler, RelTraitPropagationVisitor, RelValidityChecker

public abstract class RelVisitor
extends Object

A RelVisitor is a Visitor role in the visitor pattern and visits RelNode objects as the role of Element. Other components in the pattern: RelNode.childrenAccept(RelVisitor).

Constructor Summary

Constructors

Constructor	Description
RelVisitor()

Method Summary

Modifier and Type	Method	Description
@Nullable RelNode	go(RelNode p)	Starts an iteration.
void	replaceRoot(@Nullable RelNode node)	Replaces the root node of this traversal.
void	visit(RelNode node, int ordinal, @Nullable RelNode parent)	Visits a node during a traversal.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RelVisitor

public RelVisitor()

Method Details

visit

public void visit(RelNode node,
 int ordinal,
 @Nullable RelNode parent)

Visits a node during a traversal.

Parameters:

node - Node to visit

ordinal - Ordinal of node within its parent

parent - Parent of the node, or null if it is the root of the traversal

replaceRoot

public void replaceRoot(@Nullable RelNode node)

Replaces the root node of this traversal.

Parameters:

node - The new root node

go

public @Nullable RelNode go(RelNode p)

Starts an iteration.