/***
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2005 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.mvel2.asm.signature;

/**
 * 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): <ul> <li><i>ClassSignature</i> = (
 * <tt>visitFormalTypeParameter</tt>
 * <tt>visitClassBound</tt>?
 * <tt>visitInterfaceBound</tt>* )* ( <tt>visitSuperClass</tt>
 * <tt>visitInterface</tt>* )</li>
 * <li><i>MethodSignature</i> = ( <tt>visitFormalTypeParameter</tt>
 * <tt>visitClassBound</tt>?
 * <tt>visitInterfaceBound</tt>* )* ( <tt>visitParameterType</tt>*
 * <tt>visitReturnType</tt>
 * <tt>visitExceptionType</tt>* )</li> <li><i>TypeSignature</i> =
 * <tt>visitBaseType</tt> | <tt>visitTypeVariable</tt> |
 * <tt>visitArrayType</tt> | (
 * <tt>visitClassType</tt> <tt>visitTypeArgument</tt>* (
 * <tt>visitInnerClassType</tt> <tt>visitTypeArgument</tt>* )*
 * <tt>visitEnd</tt> ) )</li> </ul>
 *
 * @author Thomas Hallgren
 * @author Eric Bruneton
 */
public interface SignatureVisitor {

  /**
   * Wildcard for an "extends" type argument.
   */
  char EXTENDS = '+';

  /**
   * Wildcard for a "super" type argument.
   */
  char SUPER = '-';

  /**
   * Wildcard for a normal type argument.
   */
  char INSTANCEOF = '=';

  /**
   * Visits a formal type parameter.
   *
   * @param name the name of the formal parameter.
   */
  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.
   */
  SignatureVisitor visitClassBound();

  /**
   * Visits an interface bound of the last visited formal type parameter.
   *
   * @return a non null visitor to visit the signature of the interface bound.
   */
  SignatureVisitor visitInterfaceBound();

  /**
   * Visits the type of the super class.
   *
   * @return a non null visitor to visit the signature of the super class
   *         type.
   */
  SignatureVisitor visitSuperclass();

  /**
   * Visits the type of an interface implemented by the class.
   *
   * @return a non null visitor to visit the signature of the interface type.
   */
  SignatureVisitor visitInterface();

  /**
   * Visits the type of a method parameter.
   *
   * @return a non null visitor to visit the signature of the parameter type.
   */
  SignatureVisitor visitParameterType();

  /**
   * Visits the return type of the method.
   *
   * @return a non null visitor to visit the signature of the return type.
   */
  SignatureVisitor visitReturnType();

  /**
   * Visits the type of a method exception.
   *
   * @return a non null visitor to visit the signature of the exception type.
   */
  SignatureVisitor visitExceptionType();

  /**
   * Visits a signature corresponding to a primitive type.
   *
   * @param descriptor the descriptor of the primitive type, or 'V' for
   *                   <tt>void</tt>.
   */
  void visitBaseType(char descriptor);

  /**
   * Visits a signature corresponding to a type variable.
   *
   * @param name the name of the type variable.
   */
  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.
   */
  SignatureVisitor visitArrayType();

  /**
   * Starts the visit of a signature corresponding to a class or interface
   * type.
   *
   * @param name the internal name of the class or interface.
   */
  void visitClassType(String name);

  /**
   * Visits an inner class.
   *
   * @param name the local name of the inner class in its enclosing class.
   */
  void visitInnerClassType(String name);

  /**
   * Visits an unbounded type argument of the last visited class or inner
   * class type.
   */
  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.
   */
  SignatureVisitor visitTypeArgument(char wildcard);

  /**
   * Ends the visit of a signature corresponding to a class or interface type.
   */
  void visitEnd();
}
