org.eigenbase.rel
Class RelVisitor

java.lang.Object
  org.eigenbase.rel.RelVisitor

Direct Known Subclasses:

OJPreparingStmt.JavaRelFinder, RelDecorrelator.DecorrelateRelVisitor, RelOptUtil.VariableSetVisitor, RelStructuredTypeFlattener.RewriteRelVisitor, RelSubset.CheapestPlanReplacer, RelTraitPropagationVisitor, SqlToRelConverterTest.RelValidityChecker, TableAccessMap.TableRelVisitor, VisitorRelVisitor

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).

Since:

22 September, 2001

Version:

$Id: //open/dev/farrago/src/org/eigenbase/rel/RelVisitor.java#10 $

Author:

jhyde

Field Summary

private RelNode

root

Constructor Summary

RelVisitor()

Method Summary

RelNode	go(RelNode p) Starts an iteration.
void	replaceRoot(RelNode node) Replaces the root node of this traversal.
void	visit(RelNode node, int ordinal, 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

Field Detail

root

private RelNode root

Constructor Detail

RelVisitor

public RelVisitor()

Method Detail

visit

public void visit(RelNode node,
                  int ordinal,
                  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(RelNode node)

Replaces the root node of this traversal.

Parameters:

node - The new root node

go

public RelNode go(RelNode p)

Starts an iteration.