Package 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, LevelCalc, MemberCalc, StringCalc, TupleCalc, 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

Constructors

Constructor	Description
TupleValueCalc(Exp exp, TupleCalc tupleCalc, boolean nullCheck)	Creates a TupleValueCalc.

Method Summary

Modifier and Type	Method	Description
boolean	dependsOn(Hierarchy hierarchy)	Returns whether this expression depends upon a given hierarchy.
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, evaluateLevel, evaluateMember, evaluateString, evaluateTuple, evaluateVoid, numberToDouble

Methods inherited from class mondrian.calc.impl.AbstractCalc

accept, anyDepends, anyDependsButFirst, butDepends, collectArguments, getArguments, getName, getResultStyle, getType, isWrapperFor, simplifyEvaluator, unwrap

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, isWrapperFor, unwrap

Constructor Detail

TupleValueCalc

public TupleValueCalc(Exp exp,
                      TupleCalc tupleCalc,
                      boolean nullCheck)

Creates a TupleValueCalc.

Parameters:

exp - Expression

tupleCalc - Compiled expression to evaluate the tuple

nullCheck - Whether to check for null values due to non-joining dimensions in a virtual cube

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.

Overrides:

getCalcs in class AbstractCalc

dependsOn

public boolean dependsOn(Hierarchy hierarchy)

Description copied from interface: Calc

Returns whether this expression depends upon a given hierarchy.

If it does not depend on the hierarchy, 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 hierarchies except [Measures] and [Time].
• The list expression

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

  depends upon all hierarchies except [Store] and [Measures]. How so? Normally the scalar expression would depend upon all hierarchies 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:

hierarchy - Hierarchy

Returns:

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

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