/lib/saxonB/net/sf/saxon/sort/LowercaseFirstCollator.java

package net.sf.saxon.sort;





/**

 * A StringCollator that sorts lowercase before uppercase.

 *

 * <p>Case is irrelevant, unless the strings are equal ignoring

 * case, in which case lowercase comes first.</p>

 *

 * @author Michael H. Kay

 */



public class LowercaseFirstCollator implements StringCollator, java.io.Serializable {



    private StringCollator baseCollator;



    /**

     * Create a LowercaseFirstCollator

     * @param base the base collator, which determines how characters are sorted irrespective of case

     */



    public LowercaseFirstCollator(StringCollator base) {

        baseCollator = base;

    }



    /**

     * Compare two string objects: case is irrelevant, unless the strings are equal ignoring

     * case, in which case lowercase comes first.

     *

     * @return <0 if a<b, 0 if a=b, >0 if a>b

     * @throws ClassCastException if the objects are of the wrong type for this Comparer

     */



    public int compareStrings(String a, String b) {

        int diff = baseCollator.compareStrings(a, b);

        if (diff != 0) {

            return diff;

        }



        // This is doing a character-by-character comparison, which isn't really right.

        // There might be a sequence of letters constituting a single collation unit.



        int i = 0;

        int j = 0;

        while (true) {

            // Skip characters that are equal in the two strings

            while (i < a.length() && j < b.length() && a.charAt(i) == b.charAt(j)) {

                i++;

                j++;

            }

            // Skip non-letters in the first string

            while (i < a.length() && !Character.isLetter(a.charAt(i))) {

                i++;

            }

            // Skip non-letters in the second string

            while (j < b.length() && !Character.isLetter(b.charAt(j))) {

                j++;

            }

            // If we've got to the end of either string, treat the strings as equal

            if (i >= a.length()) {

                return 0;

            }

            if (j >= b.length()) {

                return 0;

            }

            // If one of the characters is lower case and the other isn't, the issue is decided

            boolean aLower = Character.isLowerCase(a.charAt(i++));

            boolean bLower = Character.isLowerCase(b.charAt(j++));

            if (aLower && !bLower) {

                return -1;

            }

            if (bLower && !aLower) {

                return +1;

            }

        }

    }



    /**

     * 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.

     */



    public Object getCollationKey(String s) {

        return baseCollator.getCollationKey(s);

    }



}



//

// The contents of this file are subject to the Mozilla Public License Version 1.0 (the "License");

// you may not use this file except in compliance with the License. You may obtain a copy of the

// License at http://www.mozilla.org/MPL/

//

// Software distributed under the License is distributed on an "AS IS" basis,

// WITHOUT WARRANTY OF ANY KIND, either express or implied.

// See the License for the specific language governing rights and limitations under the License.

//

// The Original Code is: all this file.

//

// The Initial Developer of this module is Michael H. Kay.

//

// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.

//

// Contributor(s): none.

//