org.pentaho.reporting.libraries.formula.operators
Class EqualOperator

java.lang.Object
  org.pentaho.reporting.libraries.formula.operators.EqualOperator

All Implemented Interfaces:

java.io.Serializable, InfixOperator

public class EqualOperator
extends java.lang.Object
implements InfixOperator

Creation-Date: 31.10.2006, 16:34:11

Author:

Thomas Morgner

See Also:

Serialized Form

Constructor Summary

EqualOperator()

Method Summary

TypeValuePair	evaluate(FormulaContext context, TypeValuePair value1, TypeValuePair value2) Evaluates the comptuation for both parameters.
int	getLevel()
boolean	isAssociative() Defines, whether the operation is associative.
boolean	isLeftOperation() Defines the bind-direction of the operator.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

EqualOperator

public EqualOperator()

Method Detail

evaluate

public TypeValuePair evaluate(FormulaContext context,
                              TypeValuePair value1,
                              TypeValuePair value2)
                       throws EvaluationException

Description copied from interface: InfixOperator

Evaluates the comptuation for both parameters. This method must never return null.

Specified by:

evaluate in interface InfixOperator

Returns:

Throws:

EvaluationException

getLevel

public int getLevel()

Specified by:

getLevel in interface InfixOperator

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

isLeftOperation

public boolean isLeftOperation()

Description copied from interface: InfixOperator

Defines the bind-direction of the operator. That direction defines, in which direction a sequence of equal operators is resolved.

Specified by:

isLeftOperation in interface InfixOperator

Returns:

true, if the operation is left-binding, false if right-binding

isAssociative

public boolean isAssociative()

Defines, whether the operation is associative. For associative operations, the evaluation order does not matter, if the operation appears more than once in an expression, and therefore we can optimize them a lot better than non-associative operations (ie. merge constant parts and precompute them once).

Specified by:

isAssociative in interface InfixOperator

Returns:

true, if the operation is associative, false otherwise