/*
* (c) Copyright 2005, 2006, 2007, 2008, 2009 Hewlett-Packard Development Company, LP
* All rights reserved.
* [See end of file]
*/
package lib;
import static lib.StrUtils.str;
import static lib.Lib.hashCodeObject;
public class Pair
{
A a ;
B b ;
public Pair(A a, B b) { this.a = a; this.b = b ; }
public A getLeft() { return a ; }
public B getRight() { return b ; }
public A car() { return a ; }
public B cdr() { return b ; }
@Override
public int hashCode()
{
return hashCodeObject(car()) ^ hashCodeObject(cdr())<<1 ;
}
@Override
public boolean equals(Object other)
{
if ( this == other ) return true ;
// If it's a pair of a different then .equals
// Pair(null,null) is equal to Pair(null ,null)
// Type erasure makes this hard to check otherwise.
// Use class X extends Pair and implement .equals to do
// instanceof then call super.equals.
if( ! ( other instanceof Pair ) ) return false ;
Pair,?> p2 = (Pair,?>)other ;
return Lib.equals(car(), p2.car()) && Lib.equals(cdr(), p2.cdr()) ;
}
@Override
public String toString() { return "("+str(a)+", "+str(b)+")" ; }
}
/*
* (c) Copyright 2005, 2006, 2007, 2008, 2009 Hewlett-Packard Development Company, LP
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/