/***

 * ASM: a very small and fast Java bytecode manipulation framework

 * Copyright (c) 2000-2011 INRIA, France Telecom

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the copyright holders nor the names of its

 *    contributors may be used to endorse or promote products derived from

 *    this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

package org.objectweb.asm.signature;

import org.objectweb.asm.Opcodes;

/**

 * A visitor to visit a generic signature. The methods of this interface must be

 * called in one of the three following orders (the last one is the only valid

 * order for a {@link SignatureVisitor} that is returned by a method of this

 * interface):

 * 

 * 
ClassSignature = ( <tt>visitFormalTypeParameter</tt>

 * <tt>visitClassBound</tt>? <tt>visitInterfaceBound</tt>* )* (

 * <tt>visitSuperclass</tt> <tt>visitInterface</tt>* )

 * 
MethodSignature = ( <tt>visitFormalTypeParameter</tt>

 * <tt>visitClassBound</tt>? <tt>visitInterfaceBound</tt>* )* (

 * <tt>visitParameterType</tt>* <tt>visitReturnType</tt>

 * <tt>visitExceptionType</tt>* )

 * 
TypeSignature = <tt>visitBaseType</tt> |

 * <tt>visitTypeVariable</tt> | <tt>visitArrayType</tt> | (

 * <tt>visitClassType</tt> <tt>visitTypeArgument</tt>* (

 * <tt>visitInnerClassType</tt> <tt>visitTypeArgument</tt>* )* <tt>visitEnd</tt>

 * ) )

 * 

 * 

 * @author Thomas Hallgren

 * @author Eric Bruneton

 */

public abstract class SignatureVisitor {

    /**

     * Wildcard for an "extends" type argument.

     */

    public final static char EXTENDS = '+';

    /**

     * Wildcard for a "super" type argument.

     */

    public final static char SUPER = '-';

    /**

     * Wildcard for a normal type argument.

     */

    public final static char INSTANCEOF = '=';

    /**

     * The ASM API version implemented by this visitor. The value of this field

     * must be one of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.

     */

    protected final int api;

    /**

     * Constructs a new {@link SignatureVisitor}.

     * 

     * @param api

     *            the ASM API version implemented by this visitor. Must be one

     *            of {@link Opcodes#ASM4} or {@link Opcodes#ASM5}.

     */

    public SignatureVisitor(final int api) {

        if (api != Opcodes.ASM4 && api != Opcodes.ASM5) {

            throw new IllegalArgumentException();

        }

        this.api = api;

    }

    /**

     * Visits a formal type parameter.

     * 

     * @param name

     *            the name of the formal parameter.

     */

    public void visitFormalTypeParameter(String name) {

    }

    /**

     * Visits the class bound of the last visited formal type parameter.

     * 

     * @return a non null visitor to visit the signature of the class bound.

     */

    public SignatureVisitor visitClassBound() {

        return this;

    }

    /**

     * Visits an interface bound of the last visited formal type parameter.

     * 

     * @return a non null visitor to visit the signature of the interface bound.

     */

    public SignatureVisitor visitInterfaceBound() {

        return this;

    }

    /**

     * Visits the type of the super class.

     * 

     * @return a non null visitor to visit the signature of the super class

     *         type.

     */

    public SignatureVisitor visitSuperclass() {

        return this;

    }

    /**

     * Visits the type of an interface implemented by the class.

     * 

     * @return a non null visitor to visit the signature of the interface type.

     */

    public SignatureVisitor visitInterface() {

        return this;

    }

    /**

     * Visits the type of a method parameter.

     * 

     * @return a non null visitor to visit the signature of the parameter type.

     */

    public SignatureVisitor visitParameterType() {

        return this;

    }

    /**

     * Visits the return type of the method.

     * 

     * @return a non null visitor to visit the signature of the return type.

     */

    public SignatureVisitor visitReturnType() {

        return this;

    }

    /**

     * Visits the type of a method exception.

     * 

     * @return a non null visitor to visit the signature of the exception type.

     */

    public SignatureVisitor visitExceptionType() {

        return this;

    }

    /**

     * Visits a signature corresponding to a primitive type.

     * 

     * @param descriptor

     *            the descriptor of the primitive type, or 'V' for <tt>void</tt>

     *            .

     */

    public void visitBaseType(char descriptor) {

    }

    /**

     * Visits a signature corresponding to a type variable.

     * 

     * @param name

     *            the name of the type variable.

     */

    public void visitTypeVariable(String name) {

    }

    /**

     * Visits a signature corresponding to an array type.

     * 

     * @return a non null visitor to visit the signature of the array element

     *         type.

     */

    public SignatureVisitor visitArrayType() {

        return this;

    }

    /**

     * Starts the visit of a signature corresponding to a class or interface

     * type.

     * 

     * @param name

     *            the internal name of the class or interface.

     */

    public void visitClassType(String name) {

    }

    /**

     * Visits an inner class.

     * 

     * @param name

     *            the local name of the inner class in its enclosing class.

     */

    public void visitInnerClassType(String name) {

    }

    /**

     * Visits an unbounded type argument of the last visited class or inner

     * class type.

     */

    public void visitTypeArgument() {

    }

    /**

     * Visits a type argument of the last visited class or inner class type.

     * 

     * @param wildcard

     *            '+', '-' or '='.

     * @return a non null visitor to visit the signature of the type argument.

     */

    public SignatureVisitor visitTypeArgument(char wildcard) {

        return this;

    }

    /**

     * Ends the visit of a signature corresponding to a class or interface type.

     */

    public void visitEnd() {

    }

}