Filtering Examples

Filtering Examples

Filtering 1 - Collapsing consecutive elements in a native array of Objects and an JGL container.

Filtering 2 - Selecting and rejecting elements from a container 

Filtering1 Example Code
// Copyright(c) 1996 ObjectSpace, Inc.

import jgl.*;

/**
 * Collapsing consecutive elements in a native array of Objects and an JGL container.
 * 

 * @see jgl.Filtering
 * @version 1.1
 * @author ObjectSpace, Inc.
 */

public class Filtering1
  {
  public static void main( String[] args )
    {
    String[] strings = { "gnu", "emu", "emu", "fox", "fox", "fox", "gnu" };
    ObjectIterator begin = ObjectIterator.begin( strings );
    ObjectIterator end = ObjectIterator.end( strings );
    System.out.print( "strings = " );
    Printing.println( begin, end );
    ObjectIterator last = (ObjectIterator) Filtering.unique( begin, end );
    System.out.print( "filtered strings = " );
    Printing.println( begin, end );
    int remaining = begin.distance( last );
    System.out.println( "remaining = " + remaining );
    System.out.print( "filtered array with bounds given = " );
    end.retreat( remaining );
    Printing.println( begin, end );

    Array array = new Array();
    array.add( "gnu" );
    array.add( "emu" );
    array.add( "emu" );
    array.add( "fox" );
    array.add( "fox" );
    array.add( "fox" );
    array.add( "gnu" );
    System.out.println( "array = " + array );
    Deque deque = new Deque();
    Filtering.uniqueCopy( array, new InsertIterator( deque ) );
    System.out.println( "deque = " + deque );
    }
  }


Filtering1 Example Output
strings = ( gnu, emu, emu, fox, fox, fox, gnu )
filtered strings = ( gnu, emu, fox, gnu, fox, fox, gnu )
remaining = 4
filtered array with bounds given = ( gnu, emu, fox )
array = Array( gnu, emu, emu, fox, fox, fox, gnu )
deque = Deque( gnu, emu, fox, gnu )


Filtering2 Example Code
// Copyright(c) 1996 ObjectSpace, Inc.

import jgl.*;

/**
 * Selecting and rejecting elements from a container
 * 

 * @see jgl.Filtering
 * @version 1.1
 * @author ObjectSpace, Inc.
 */

public class Filtering2
  {
  public static void main( String[] args )
    {
    Array array = new Array();
    array.add( "cat" );
    array.add( "monkey" );
    array.add( "lion" );
    array.add( "armadillo" );
    array.add( "zebra" );
    System.out.println( "array = " + array );

    System.out.println( "Collecting strings > 5 chars  == " 
                        + Filtering.select( array, new Filtering2UnaryPredicate() ) );
    System.out.println( "Rejecting strings > 5 chars   == " 
                        + Filtering.reject( array, new Filtering2UnaryPredicate() ) );
    }
  }

class Filtering2UnaryPredicate implements UnaryPredicate
  {
  // return true if the length of the toString() is
  // greater than 5.
  public boolean execute( Object object )
    {
    return object.toString().length() > 5;
    }
  }

Filtering2 Example Output
array = Array( cat, monkey, lion, armadillo, zebra )
Collecting strings > 5 chars  == Array( monkey, armadillo )
Rejecting strings > 5 chars   == Array( cat, lion, zebra )