/* * Copyright 2009-2010 MBTE Sweden AB. * * Licensed 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. */ package groovy.lang; import org.codehaus.groovy.transform.GroovyASTTransformationClass; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; import java.lang.annotation.ElementType; /** * Struct is marker annotation for special type of classes with following properties * - super class is either Object or also Struct * - the class has protected no-arg constructor, so it can't be instantiated directly * - if such constructor does not exist a compile time error will happen * - any other constructor will lead to compile time error as well * - the only way to instantiate struct is via inner Builder class * - each Struct has inner class Builder * - Builder has all the same properties as it's outer class but mutable * - there are no any methods except getters * - properties of Struct are one of the following * - classes implementing Struct * - primitive types (including boxed versions) * - strings * - uiids * - immutable lists of classes allowed as fields in Struct * - immutable sets of classes allowed as fields in Struct * - immutable maps with keys and value of classes allowed as fields in Struct */ @Retention(RetentionPolicy.SOURCE) @Target(ElementType.TYPE) public @interface Struct { }