/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
 * third-party contributors as indicated by either @author tags or express
 * copyright attribution statements applied by the authors.  All
 * third-party contributions are distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.jpa.criteria.predicate;


Models what ANSI-SQL terms a truth value.  Specifically, ANSI-SQL defines TRUE, FALSE and
UNKNOWN as truth values.  These truth values are used to explicitly check the result of a
boolean expression (the syntax is like a > b IS TRUE.  IS TRUE is the assumed default.

JPA defines support for only IS TRUE and IS FALSE, not IS UNKNOWN (a > NULL
is an example where the result would be UNKNOWN).  All 3 are provided here for completness.
Author:
Steve Ebersole/**
 * Models what ANSI-SQL terms a <i>truth value</i>.  Specifically, ANSI-SQL defines <tt>TRUE</tt>, <tt>FALSE</tt> and
 * <tt>UNKNOWN</tt> as <i>truth values</i>.  These <i>truth values</i> are used to explicitly check the result of a
 * boolean expression (the syntax is like <tt>a > b IS TRUE</tt>.  <tt>IS TRUE</tt> is the assumed default.
 * <p/>
 * JPA defines support for only <tt>IS TRUE</tt> and <tt>IS FALSE</tt>, not <tt>IS UNKNOWN</tt> (<tt>a > NULL</tt>
 * is an example where the result would be UNKNOWN).  All 3 are provided here for completness.
 *
 * @author Steve Ebersole
 */
public enum TruthValue {
	TRUE,
	FALSE,
	UNKNOWN
}