content: /*
   *  Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you under the Apache License, Version 2.0 (the
   *  "License"); you may not use this file except in compliance
   *  with the License.  You may obtain a copy of the License at
   *
   *        http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing,
   *  software distributed under the License is distributed on an
   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   *  KIND, either express or implied.  See the License for the
   *  specific language governing permissions and limitations
   *  under the License.
   */
  
  /**
   * This package defines a {@link org.apache.causeway.applib.spec.Specification}
   * interface (and various implementations), used by the
   * {@link org.apache.causeway.applib.annotation.MustSatisfy} annotation to
   * declare valid values for properties or parameters.
   *
   * <p>
   * This is an implementation of the DDD &quot;Specification&quot;, allowing
   * validation that might otherwise be repeated for both properties and
   * parameters (in the <tt>validateXxx()</tt> methods to be factored out.
   *
   * <p>
   * That said, there is still some repetition in that the {@link org.apache.causeway.applib.annotation.MustSatisfy}
   * annotation must be applied in all appropriate cases.  If it is the case that
   * the validation rules would apply <i>every</i> case, then it is generally
   * preferable to implement a {@link org.apache.causeway.applib.annotation.Value} type
   * through the {@link org.apache.causeway.applib.value.semantics.ValueSemanticsProvider}
   * interface.
   */
  package org.apache.causeway.applib.spec;