org.pentaho.reporting.libraries.formula.operators

Interface InfixOperator

All Superinterfaces:

java.io.Serializable

All Known Implementing Classes:

AbstractCompareOperator, AbstractNumericOperator, AddOperator, ConcatOperator, DivideOperator, EqualOperator, GreaterEqualOperator, GreaterOperator, LesserEqualOperator, LesserOperator, MultiplyOperator, NotEqualOperator, PowerOperator, SubtractOperator

public interface InfixOperator
extends java.io.Serializable

An operator. An operator always takes two arguments. Prefix and postfix operators are implemented differently.

Author:

Thomas Morgner

Method Summary

Modifier and Type	Method and Description
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.

Method Detail

evaluate

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

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

Parameters:

context -

value1 -

value2 -

Returns:

Throws:

EvaluationException

getLevel

int getLevel()

isLeftOperation

boolean isLeftOperation()

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

Returns:

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

isAssociative

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).

Returns:

true, if the operation is associative, false otherwise