| /* |
| * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Sun designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Sun in the LICENSE file that accompanied this code. |
| * |
| * This code 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 General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| */ |
| |
| package javax.lang.model.type; |
| |
| import javax.lang.model.element.*; |
| |
| /** |
| * A visitor of types, in the style of the |
| * visitor design pattern. Classes implementing this |
| * interface are used to operate on a type when the kind of |
| * type is unknown at compile time. When a visitor is passed to a |
| * type's {@link TypeMirror#accept accept} method, the <tt>visit<i>XYZ</i></tt> |
| * method most applicable to that type is invoked. |
| * |
| * <p> Classes implementing this interface may or may not throw a |
| * {@code NullPointerException} if the additional parameter {@code p} |
| * is {@code null}; see documentation of the implementing class for |
| * details. |
| * |
| * <p> <b>WARNING:</b> It is possible that methods will be added to |
| * this interface to accommodate new, currently unknown, language |
| * structures added to future versions of the Java™ programming |
| * language. Therefore, visitor classes directly implementing this |
| * interface may be source incompatible with future versions of the |
| * platform. To avoid this source incompatibility, visitor |
| * implementations are encouraged to instead extend the appropriate |
| * abstract visitor class that implements this interface. However, an |
| * API should generally use this visitor interface as the type for |
| * parameters, return type, etc. rather than one of the abstract |
| * classes. |
| * |
| * @param <R> the return type of this visitor's methods. Use {@link |
| * Void} for visitors that do not need to return results. |
| * @param <P> the type of the additional parameter to this visitor's |
| * methods. Use {@code Void} for visitors that do not need an |
| * additional parameter. |
| * |
| * @author Joseph D. Darcy |
| * @author Scott Seligman |
| * @author Peter von der Ahé |
| * @since 1.6 |
| */ |
| public interface TypeVisitor<R, P> { |
| /** |
| * Visits a type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visit(TypeMirror t, P p); |
| |
| /** |
| * A convenience method equivalent to {@code v.visit(t, null)}. |
| * @param t the element to visit |
| * @return a visitor-specified result |
| */ |
| R visit(TypeMirror t); |
| |
| /** |
| * Visits a primitive type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitPrimitive(PrimitiveType t, P p); |
| |
| /** |
| * Visits the null type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitNull(NullType t, P p); |
| |
| /** |
| * Visits an array type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitArray(ArrayType t, P p); |
| |
| /** |
| * Visits a declared type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitDeclared(DeclaredType t, P p); |
| |
| /** |
| * Visits an error type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitError(ErrorType t, P p); |
| |
| /** |
| * Visits a type variable. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitTypeVariable(TypeVariable t, P p); |
| |
| /** |
| * Visits a wildcard type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitWildcard(WildcardType t, P p); |
| |
| /** |
| * Visits an executable type. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitExecutable(ExecutableType t, P p); |
| |
| /** |
| * Visits a {@link NoType} instance. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| */ |
| R visitNoType(NoType t, P p); |
| |
| /** |
| * Visits an unknown kind of type. |
| * This can occur if the language evolves and new kinds |
| * of types are added to the {@code TypeMirror} hierarchy. |
| * @param t the type to visit |
| * @param p a visitor-specified parameter |
| * @return a visitor-specified result |
| * @throws UnknownTypeException |
| * a visitor implementation may optionally throw this exception |
| */ |
| R visitUnknown(TypeMirror t, P p); |
| } |