net.sf.saxon.expr.sort
Class AlphanumericCollator

java.lang.Object
  extended by net.sf.saxon.expr.sort.AlphanumericCollator
All Implemented Interfaces:
Serializable, StringCollator

public class AlphanumericCollator
extends Object
implements StringCollator, Serializable

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().

See Also:
Serialized Form

Constructor Summary
AlphanumericCollator(StringCollator base)
          Create an alphanumeric collation
 
Method Summary
 boolean comparesEqual(String s1, String s2)
          Compare two strings for equality.
 int compareStrings(String s1, String s2)
          Compare two objects.
 Object getCollationKey(String s)
          Get a collation key for two Strings.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

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

compareStrings

public int compareStrings(String s1,
                          String s2)
Compare two objects.

Specified by:
compareStrings in interface StringCollator
Parameters:
s1 - the first string
s2 - the second string
Returns:
<0 if a0 if a>b

comparesEqual

public boolean comparesEqual(String s1,
                             String 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 Object getCollationKey(String s)
Get a collation key for two Strings. The essential property of collation keys is that if two values are equal under the collation, then the collation keys are compare correctly under the equals() method.

Specified by:
getCollationKey in interface StringCollator
Parameters:
s - the string whose collation key is required
Returns:
the collation key


Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.