Package net.sf.saxon.expr.sort

Class AlphanumericCollator

java.lang.Object

net.sf.saxon.expr.sort.AlphanumericCollator

All Implemented Interfaces:

StringCollator

public class AlphanumericCollator
extends java.lang.Object
implements StringCollator

A Comparer that treats strings as an alternating sequence of alpha parts and numeric parts. The alpha parts are compared using a base collation supplied as a parameter; the numeric parts are compared numerically. "Numeric" here means a sequence of consecutive ASCII digits 0-9.

Note: this StringCollator produces an ordering that is not compatible with equals().

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	PREFIX

Constructor Summary

Constructors

Constructor	Description
AlphanumericCollator(StringCollator base)	Create an alphanumeric collation

Method Summary

Modifier and Type	Method	Description
boolean	comparesEqual(UnicodeString s1, UnicodeString s2)	Compare two strings for equality.
int	compareStrings(UnicodeString cs1, UnicodeString cs2)	Compare two objects.
AtomicMatchKey	getCollationKey(UnicodeString cs)	Get a collation key for a String.
java.lang.String	getCollationURI()	Get the collation URI.

Methods inherited from class java.lang.Object

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

Field Detail

PREFIX

public static final java.lang.String PREFIX

See Also:

Constant Field Values

Constructor Detail

AlphanumericCollator

public AlphanumericCollator(StringCollator base)

Create an alphanumeric collation

Parameters:

base - the collation used to compare the alphabetic parts of the string

Method Detail

getCollationURI

public java.lang.String getCollationURI()

Get the collation URI. It must be possible to use this collation URI to reconstitute the collation

Specified by:

getCollationURI in interface StringCollator

Returns:

a collation URI that can be used to reconstruct the collation when an XSLT package is reloaded.

compareStrings

public int compareStrings(UnicodeString cs1,
                          UnicodeString cs2)

Compare two objects.

Specified by:

compareStrings in interface StringCollator

Parameters:

cs1 - the first string

cs2 - the second string

Returns:

<0 if a<b, 0 if a=b, >0 if a>b

comparesEqual

public boolean comparesEqual(UnicodeString s1,
                             UnicodeString s2)

Compare two strings for equality. This may be more efficient than using compareStrings and testing whether the result is zero, but it must give the same result

Specified by:

comparesEqual in interface StringCollator

Parameters:

s1 - the first string

s2 - the second string

Returns:

true if and only if the strings are considered equal,

getCollationKey

public AtomicMatchKey getCollationKey(UnicodeString cs)

Get a collation key for a String. The essential property of collation keys is that if (and only if) two strings are equal under the collation, then comparing the collation keys using the equals() method must return true.

Specified by:

getCollationKey in interface StringCollator

Parameters:

cs - the string whose collation key is required

Returns:

the collation key