mondrian.calc.impl
Class TupleValueCalc

java.lang.Object
  mondrian.calc.impl.AbstractCalc
      mondrian.calc.impl.GenericCalc
          mondrian.calc.impl.TupleValueCalc

All Implemented Interfaces:

BooleanCalc, Calc, DateTimeCalc, DimensionCalc, DoubleCalc, HierarchyCalc, IntegerCalc, IterCalc, LevelCalc, ListCalc, MemberCalc, MemberListCalc, StringCalc, TupleCalc, TupleListCalc, VoidCalc

public class TupleValueCalc
extends GenericCalc

Expression which evaluates a tuple expression, sets the dimensional context to the result of that expression, then yields the value of the current measure in the current dimensional context.

The evaluator's context is preserved.

Since:

Sep 27, 2005

Author:

jhyde

See Also:

ValueCalc, MemberValueCalc

Field Summary

Fields inherited from class mondrian.calc.impl.AbstractCalc

exp, type

Constructor Summary

TupleValueCalc(Exp exp, TupleCalc tupleCalc)

Method Summary

boolean	dependsOn(Dimension dimension) Returns whether this expression depends upon a given dimension.
Object	evaluate(Evaluator evaluator) Evaluates this expression.
Calc[]	getCalcs() Returns this expression's child expressions.
Calc	optimize() Optimizes the scalar evaluation of a tuple.

Methods inherited from class mondrian.calc.impl.GenericCalc

evaluateBoolean, evaluateDateTime, evaluateDimension, evaluateDouble, evaluateHierarchy, evaluateInteger, evaluateIterable, evaluateLevel, evaluateList, evaluateMember, evaluateMemberIterable, evaluateMemberList, evaluateString, evaluateTuple, evaluateTupleIterable, evaluateTupleList, evaluateVoid, numberToDouble

Methods inherited from class mondrian.calc.impl.AbstractCalc

accept, anyDepends, anyDependsButFirst, butDepends, getArguments, getName, getResultStyle, getType, simplifyEvaluator

Methods inherited from class java.lang.Object

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

Methods inherited from interface mondrian.calc.Calc

accept, getResultStyle, getType

Constructor Detail

TupleValueCalc

public TupleValueCalc(Exp exp,
                      TupleCalc tupleCalc)

Method Detail

evaluate

public Object evaluate(Evaluator evaluator)

Description copied from interface: Calc

Evaluates this expression.

Parameters:

evaluator - Provides dimensional context in which to evaluate this expression

Returns:

Result of expression evaluation

getCalcs

public Calc[] getCalcs()

Description copied from class: AbstractCalc

Returns this expression's child expressions.

Specified by:

getCalcs in class AbstractCalc

dependsOn

public boolean dependsOn(Dimension dimension)

Description copied from interface: Calc

Returns whether this expression depends upon a given dimension.

If it does not depend on the dimension, then re-evaluating the expression with a different member of this context must produce the same answer.

Some examples:

• The expression

  [Measures].[Unit Sales]

  depends on all dimensions except [Measures].
• The boolean expression

  ([Measures].[Unit Sales], [Time].[1997]) > 1000

  depends on all dimensions except [Measures] and [Time].
• The list expression

  Filter([Store].[USA].Children, [Measures].[Unit Sales] < 50)

  depends upon all dimensions except [Store] and [Measures]. How so? Normally the scalar expression would depend upon all dimensions except [Measures], but the Filter function sets the [Store] context before evaluating the scalar expression, so it is not inherited from the surrounding context.

Specified by:

dependsOn in interface Calc

Overrides:

dependsOn in class AbstractCalc

Parameters:

dimension - Dimension

Returns:

Whether this expression's result depends upon the current member of the dimension

optimize

public Calc optimize()

Optimizes the scalar evaluation of a tuple. It evaluates the members of the tuple, sets the context to these members, and evaluates the scalar result in one step, without generating a tuple.

This is useful when evaluating calculated members:

WITH MEMBER [Measures].[Sales last quarter]
   AS ' ([Measures].[Unit Sales], [Time].PreviousMember '

Returns:

optimized expression