net.sf.saxon.sort
Class DecimalSortComparer

java.lang.Object
  net.sf.saxon.sort.DecimalSortComparer

All Implemented Interfaces:

Serializable, AtomicComparer

public class DecimalSortComparer
extends Object
implements AtomicComparer

An AtomicComparer used for sorting values that are known to be instances of xs:decimal (including xs:integer), It also supports a separate method for getting a collation key to test equality of items

Author:

Michael H. Kay

See Also:

Serialized Form

Method Summary

int	compareAtomicValues(AtomicValue a, AtomicValue b) Compare two AtomicValue objects according to the rules for their data type.
boolean	comparesEqual(AtomicValue a, AtomicValue b) Test whether two values compare equal.
ComparisonKey	getComparisonKey(AtomicValue a) Get a comparison key for an object.
static DecimalSortComparer	getInstance()

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static DecimalSortComparer getInstance()

compareAtomicValues

public int compareAtomicValues(AtomicValue a,
                               AtomicValue b)

Compare two AtomicValue objects according to the rules for their data type. UntypedAtomic values are compared as if they were strings; if different semantics are wanted, the conversion must be done by the caller.

Specified by:

compareAtomicValues in interface AtomicComparer

Parameters:

a - the first object to be compared.

b - the second object to be compared. This must be comparable with the first object: for example, if one is a string, they must both be strings.

Returns:

<0 if a0 if a>b

Throws:

ClassCastException - if the objects are not comparable

comparesEqual

public boolean comparesEqual(AtomicValue a,
                             AtomicValue b)

Test whether two values compare equal.

Specified by:

comparesEqual in interface AtomicComparer

Parameters:

a - the first object to be compared.

b - the second object to be compared.

Returns:

true if the values are equal, false if not

getComparisonKey

public ComparisonKey getComparisonKey(AtomicValue a)

Get a comparison key for an object. This must satisfy the rule that if two objects are equal as defined by the XPath eq operator, then their comparison keys are equal as defined by the Java equals() method, and vice versa. There is no requirement that the comparison keys should reflect the ordering of the underlying objects.

Specified by:

getComparisonKey in interface AtomicComparer