/*

 * Copyright (c) 2017, Oracle and/or its affiliates. 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.

 *

 * 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package jdk.experimental.bytecode;

import java.util.Iterator;

/**

 * Helper to create and manipulate type descriptors of T.

 *

 * @param <S> the type of symbols

 * @param <T> the type of type descriptors

 */

public interface TypeHelper<S, T> {

    /**

     * Return the type descriptor of an element given the type

     * descriptor of an array.

     *

     * @param t the type descriptor of the array

     * @return the element type

     */

    T elemtype(T t);

    /**

     * Return the type descriptor of an array given the type descriptor

     * of an element.

     *

     * @param t the type descriptor of the element

     * @return the type descriptor of the array

     */

    T arrayOf(T t);

    /**

     * Return an iterator over the type descriptors of the parameters of a

     * method.

       *

     * @param t the method type descriptor

     * @return an iterator over the type descriptors of the parameters

     */

    Iterator<T> parameterTypes(T t);

    /**

     * Return the type descriptor of a {@code TypeTag}.

     *

     * @param tag the {@code TypeTag} of a primitive type

     * @return the type descriptor of the primitive type

     */

    T fromTag(TypeTag tag);

    /**

     * Return the return type descriptor of a method.

     *

     * @param t the method type descriptor

     * @return the return type descriptor

     */

    T returnType(T t);

    /**

     * Return the type descriptor for a symbol.

     *

     * @param s the symbol

     * @return the type descriptor

     */

    T type(S s);

    /**

     * Return the symbol corresponding to a type descriptor.

     *

     * @param type the type descriptor

     * @return the symbol

     */

    S symbol(T type);

    /**

     * Return the {@code TypeTag} corresponding to a type descriptor.  Reference

     * types return {@code TypeTag.A}.

     *

     * @param t a type descriptor

     * @return the corresponding {@code TypeTag}

     */

    TypeTag tag(T t);

    /**

     * Return the symbol corresponding to a JVM type descriptor string.

     *

     * @param s a JVM type descriptor string

     * @return the corresponding symbol

     */

    S symbolFrom(String s);

    /**

     * Return the common supertype descriptor of two type descriptors.

     *

     * @param t1 a type descriptor

     * @param t2 a type descriptor

     * @return the common supertype descriptor

     */

    T commonSupertype(T t1, T t2);

    /**

     * Return the type descriptor for the null type.

     *

     * @return the type descriptor for the null type

     */

    T nullType();

}