FinalSet.java

package org.wikipedia.miner.util.text.yagoUtils;
import java.util.AbstractList;
import java.util.Arrays;
import java.util.Set;

/** 
This class is part of the Java Tools (see http://mpii.de/yago-naga/javatools).
It is licensed under the Creative Commons Attribution License 
(see http://creativecommons.org/licenses/by/3.0) by 
the YAGO-NAGA team (see http://mpii.de/yago-naga).
  

  
 

This class provides a very simple container implementation with zero overhead.
A FinalSet bases on a sorted, unmodifiable array. The constructor
can either be called with a sorted unmodifiable array (default constructor)
or with an array that can be cloned and sorted beforehand if desired. 
Example:
<PRE>
   FinalSet<String> f=new FinalSet("a","b","c");
   // equivalently: 
   //   FinalSet<String> f=new FinalSet(new String[]{"a","b","c"});
   //   FinalSet<String> f=new FinalSet(SHALLNOTBECLONED,ISSORTED,"a","b","c");
   System.out.println(f.get(1));
   --> b
</PRE>
*/
public class FinalSet<T extends Comparable> extends AbstractList<T> implements Set<T>{
  /** Holds the data, must be sorted */
  public T[] data;  
  /** Constructs a FinalSet from an array, clones and sorts the array if indicated. */
  @SuppressWarnings("unchecked")
  public FinalSet(boolean clone,T... a) {
    if(clone) {
      Comparable[] b=new Comparable[a.length];
      System.arraycopy(a,0,b,0,a.length);
      a=(T[])b;
    }
    Arrays.sort(a);
    data=a;
  }
  /** Constructs a FinalSet from an array that does not need to be cloned */
  public FinalSet(T... a) {
    this(false,a);
  }
  /** Tells whether x is in the container */
  public boolean contains(T x) {
    return(Arrays.binarySearch(data,x)>=0);
  }
  /** Returns the position in the array or -1 */
  public int indexOf(T x) {
    int r=Arrays.binarySearch(data,x);
    return(r>=0?r:-1);
  }
  /** Returns the element at position i*/
    @Override
  public T get(int i) {
    return(data[i]);
  }
  
  /** Returns the number of elements in this FinalSet */
    @Override
  public int size() {
    return(data.length);
  }
  
//  /** Test routine */
//  public static void main(String[] args) {
//    FinalSet<String> f=new FinalSet<String>("b","a","c");
//  }
}