mondrian.calc
Interface TupleCalc

All Superinterfaces:

Calc

All Known Implementing Classes:

AbstractTupleCalc, AbstractVoidCalc, CacheCalc, ConstantCalc, GenericCalc, MemberValueCalc, TupleFunDef.CalcImpl, TupleValueCalc, ValueCalc

public interface TupleCalc
extends Calc

Expression which yields a tuple.

The tuple is represented as an array of Member objects, null to represent the null tuple.

When implementing this interface, it is convenient to extend AbstractTupleCalc, but it is not required.

Since:

Sep 27, 2005

Author:

jhyde

Method Summary

Member[]

evaluateTuple(Evaluator evaluator) Evaluates this expression to yield a tuple.

Methods inherited from interface mondrian.calc.Calc

accept, dependsOn, evaluate, getResultStyle, getType

Method Detail

evaluateTuple

Member[] evaluateTuple(Evaluator evaluator)

Evaluates this expression to yield a tuple.

A tuple cannot contain any null members. If any of the members is null, this method must return a null.

Post-condition:

result == null || !tupleContainsNullMember(result)

Parameters:

evaluator - Evaluation context

Returns:

an array of members, or null to represent the null tuple