org.eigenbase.rex
Class RexLocalRef

java.lang.Object
  org.eigenbase.rex.RexNode
      org.eigenbase.rex.RexVariable
          org.eigenbase.rex.RexSlot
              org.eigenbase.rex.RexLocalRef

public class RexLocalRef
extends RexSlot

Local variable.

Identity is based upon type and index. We want multiple references to the same slot in the same context to be equal. A side effect is that references to slots in different contexts which happen to have the same index and type will be considered equal; this is not desired, but not too damaging, because of the immutability.

Variables are immutable.

Since:

Oct 25, 2005

Version:

$Id: //open/dev/farrago/src/org/eigenbase/rex/RexLocalRef.java#10 $

Author:

jhyde

Field Summary

private static String[]

names

Fields inherited from class org.eigenbase.rex.RexSlot

index

Fields inherited from class org.eigenbase.rex.RexVariable

name, type

Fields inherited from class org.eigenbase.rex.RexNode

digest, EMPTY_ARRAY

Constructor Summary

RexLocalRef(int index, RelDataType type)
Creates a local variable.

Method Summary

<R> R	accept(RexVisitor<R> visitor) Accepts a visitor, dispatching to the right overloaded visitXxx method.
RexLocalRef	clone()
private static String	createName(int index)
boolean	equals(Object obj)
int	hashCode()

Methods inherited from class org.eigenbase.rex.RexSlot

getIndex, makeArray

Methods inherited from class org.eigenbase.rex.RexVariable

getName, getType

Methods inherited from class org.eigenbase.rex.RexNode

getKind, isA, isAlwaysTrue, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

names

private static final String[] names

Constructor Detail

RexLocalRef

public RexLocalRef(int index,
                   RelDataType type)

Creates a local variable.

Parameters:

index - Index of the field in the underlying rowtype

type - Type of the column

"Precondition:"

type != null, index >= 0

Method Detail

clone

public RexLocalRef clone()

Specified by:

clone in class RexNode

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

accept

public <R> R accept(RexVisitor<R> visitor)

Description copied from class: RexNode

Accepts a visitor, dispatching to the right overloaded visitXxx method.

Also see RexProgram.apply(RexVisitor, RexNode[], RexNode), which applies a visitor to several expressions simultaneously.

Specified by:

accept in class RexNode

createName

private static String createName(int index)