net.sf.saxon.sort
Class TextComparer

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

All Implemented Interfaces:

Serializable, AtomicComparer

public class TextComparer
extends Object
implements AtomicComparer, Serializable

A Comparer used for comparing sort keys when data-type="text". The items to be compared are converted to strings, and the strings are then compared using an underlying collator

Author:

Michael H. Kay

See Also:

Serialized Form

Constructor Summary

TextComparer(AtomicComparer baseComparer)

Method Summary

int	compareAtomicValues(AtomicValue a, AtomicValue b) Compare two Items by converting them to strings and comparing the string values.
boolean	comparesEqual(AtomicValue a, AtomicValue b) Compare two AtomicValue objects for equality according to the rules for their data type.
AtomicComparer	getBaseComparer() Get the underlying comparer (which doesn't do conversion to string)
ComparisonKey	getComparisonKey(AtomicValue a) Get a comparison key for an object.

Methods inherited from class java.lang.Object

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

Constructor Detail

TextComparer

public TextComparer(AtomicComparer baseComparer)

Method Detail

getBaseComparer

public AtomicComparer getBaseComparer()

Get the underlying comparer (which doesn't do conversion to string)

compareAtomicValues

public int compareAtomicValues(AtomicValue a,
                               AtomicValue b)
                        throws ClassCastException

Compare two Items by converting them to strings and comparing the string values.

Specified by:

compareAtomicValues in interface AtomicComparer

Parameters:

a - the first Item to be compared.

b - the second Item to be compared.

Returns:

<0 if a0 if a>b

Throws:

ClassCastException - if the objects are not Items, or are items that cannot be convered to strings (e.g. QNames)

comparesEqual

public boolean comparesEqual(AtomicValue a,
                             AtomicValue b)

Compare two AtomicValue objects for equality according to the rules for their data type. UntypedAtomic values are compared by converting to the type of the other operand.

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

Throws:

ClassCastException - if the objects are not comparable

getComparisonKey

public ComparisonKey getComparisonKey(AtomicValue a)

Get a comparison key for an object. This must satisfy the rule that if two objects are equal according to the XPath eq operator, then their comparison keys are equal according to 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