package java.text;

import java.util.Comparator;

import javascript.ScriptHelper;


/**
 * The Collator class performs locale-sensitive String comparison.
 * You use this class to build searching and sorting routines for natural language text.
 * 
 * @author j2js
 */
public abstract class Collator implements Comparator<Object> {
    
    protected Collator() {}
    
    // According the ECMAScript Language Specification, the method localeCompare must return 
    // 0 or ?-0 when comparing two strings that are considered canonically equivalent by the Unicode standard.
    // This is not honored by Safari. As a workaround, we compute the offset to the expected 0 value. Calls
    // method String.compareTo are then corrected by this value.
    static int equalityOffset = ScriptHelper.evalInt("'a'.localeCompare('a')");

    public int compare(Object o1, Object o2) {
        return compare((String) o1, (String) o2);
    }
    
    public abstract int compare(String o1, String o2);
    
    /**
     * Gets the Collator for the desired locale.
     */
    public static Collator getInstance() {
        return new Collator() {
            public int compare(String s1, String s2) {
                ScriptHelper.put("s1", s1);
                ScriptHelper.put("s2", s2);
                return ScriptHelper.evalInt("s1.localeCompare(s2)") - equalityOffset;
            }
        };
    }
    
}

Extracted from /projects/j2js-Runtime/src/java/text/Collator.java