/*

  Copyright 2004-2008 Paul R. Holser, Jr.  All rights reserved.

  Licensed under the Academic Free License version 3.0

  */

 package jaggregate.internal;

 import static java.lang.String.*;

 /**

  * Constants and methods used internally for performing checks on method arguments.

  *

  * @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>

  * @version $Id: ArgumentChecks.java,v 1.4 2008/10/03 19:01:23 pholser Exp $

  */

 public class ArgumentChecks {

     public static final String DISCRIMINATOR = "discriminator";

     public static final String OPERATION = "operation";

     public static final String TRANSFORMER = "transformer";

     public static final String EMPTY_SEQUENCE = "empty sequence";

     public static final String REPLACEMENT_SEQUENCE = "replacement sequence";

     public static final String SEQUENCE = "sequence";

     public static final String COLLECTION = "collection";

     public static final String MAPPER = "mapper";

     public static final String STARTING_INDEX = "starting";

     public static final String ENDING_INDEX = "ending";

     public static final String ADDITION_INDEX = "addition";

     public static final String NEGATIVE_AMOUNT = "illegal negative amount: ";

     public static final String EXPECTED_SEQUENCE_SIZE =

         "expecting sequence to have size ";

     public static final String BUT_WAS = ", was ";

     public static final String ITERABLE = "iterable";

     private static final String NULL_FORMAT = "illegal null %1$s";

     /**

      * Discourages instantiation.

      *

      * @throws UnsupportedOperationException always

      */

     protected ArgumentChecks() {

         throw new UnsupportedOperationException();

     }

     /**

      * Raises an exception with the given failure message if the given object is

      * {@code null}.

      *

      * @param target object to check

      * @param failureMessage message to populate the exception with if {@code target}

      * is {@code null}

      * @throws NullPointerException if {@code target} is {@code null}

      */

     public static void ensureNotNull( Object target, String failureMessage ) {

         if ( target == null )

             throw new NullPointerException( format( NULL_FORMAT, failureMessage ) );

     }

 }