uk.ac.ed.epcc.safe.accounting

Class IndexReduction

java.lang.Object

uk.ac.ed.epcc.safe.accounting.ReductionTarget<java.lang.Object>

uk.ac.ed.epcc.safe.accounting.IndexReduction

public class IndexReduction
extends ReductionTarget<java.lang.Object>

A ReductionTarget that generates an index value similar to an SQL GROUP BY clause.

Author:

spb

Constructor Summary

Constructors

Constructor and Description
IndexReduction(PropExpression<?> tag)

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Object	combine(java.lang.Object a, java.lang.Object b) Combine two partial values.

Methods inherited from class uk.ac.ed.epcc.safe.accounting.ReductionTarget

equals, getDefault, getExpression, getReduction, getTarget, hashCode, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

IndexReduction

public IndexReduction(PropExpression<?> tag)
               throws IllegalReductionException

Throws:

IllegalReductionException

Method Detail

combine

public java.lang.Object combine(java.lang.Object a,
                       java.lang.Object b)

Description copied from class: ReductionTarget

Combine two partial values. The default value must be a legal input

Specified by:

combine in class ReductionTarget<java.lang.Object>

Returns:

combined result