net.sf.saffron.rex
Class RexNode

java.lang.Object
  |
  +--net.sf.saffron.rex.RexNode

Direct Known Subclasses:

InternalTranslator.RexQuery, JavaRowExpression, RexCall, RexFieldAccess, RexList, RexLiteral, RexRangeRef, RexVariable

public abstract class RexNode

extends Object

Row expression.

Every row-expression has a type. (Compare with SqlNode, which is created before validation, and therefore types may not be available.)

Some common row-expressions are: RexLiteral (constant value), RexVariable (variable), RexCall (call to operator with operands). Expressions are generally created using a RexBuilder factory.

Since:

Nov 22, 2003

Version:

$Id: $

Author:

jhyde

Field Summary

protected String

digest

Constructor Summary

RexNode()

Method Summary

abstract Object	clone()
RexKind	getKind() Returns the kind of node this is.
abstract SaffronType	getType()
boolean	isA(RexKind kind)
boolean	isAlwaysTrue() Returns whether this expression always returns true.
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

digest

protected String digest

Constructor Detail

RexNode

public RexNode()

Method Detail

getType

public abstract SaffronType getType()

clone

public abstract Object clone()

Overrides:

clone in class Object

isAlwaysTrue

public boolean isAlwaysTrue()

Returns whether this expression always returns true. (Such as if this expression is equal to the literal TRUE.)

isA

public boolean isA(RexKind kind)

getKind

public RexKind getKind()

Returns the kind of node this is.

Returns:

A RexKind value, never null

Post-condition:

return != null

toString

public String toString()

Overrides:

toString in class Object