1 /* 2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 package jdk.experimental.bytecode; 25 26 import java.util.Iterator; 27 28 /** 29 * Helper to create and manipulate type descriptors of T. 30 * 31 * @param <S> the type of symbols 32 * @param <T> the type of type descriptors 33 */ 34 public interface TypeHelper<S, T> { 35 /** 36 * Return the type descriptor of an element given the type 37 * descriptor of an array. 38 * 39 * @param t the type descriptor of the array 40 * @return the element type 41 */ 42 T elemtype(T t); 43 44 /** 45 * Return the type descriptor of an array given the type descriptor 46 * of an element. 47 * 48 * @param t the type descriptor of the element 49 * @return the type descriptor of the array 50 */ 51 T arrayOf(T t); 52 53 /** 54 * Return an iterator over the type descriptors of the parameters of a 55 * method. 56 * 57 * @param t the method type descriptor 58 * @return an iterator over the type descriptors of the parameters 59 */ 60 Iterator<T> parameterTypes(T t); 61 62 /** 63 * Return the type descriptor of a {@code TypeTag}. 64 * 65 * @param tag the {@code TypeTag} of a primitive type 66 * @return the type descriptor of the primitive type 67 */ 68 T fromTag(TypeTag tag); 69 70 /** 71 * Return the return type descriptor of a method. 72 * 73 * @param t the method type descriptor 74 * @return the return type descriptor 75 */ 76 T returnType(T t); 77 78 /** 79 * Return the type descriptor for a symbol. 80 * 81 * @param s the symbol 82 * @return the type descriptor 83 */ 84 T type(S s); 85 86 /** 87 * Return the symbol corresponding to a type descriptor. 88 * 89 * @param type the type descriptor 90 * @return the symbol 91 */ 92 S symbol(T type); 93 94 /** 95 * Return the {@code TypeTag} corresponding to a type descriptor. Reference 96 * types return {@code TypeTag.A}. 97 * 98 * @param t a type descriptor 99 * @return the corresponding {@code TypeTag} 100 */ 101 TypeTag tag(T t); 102 103 /** 104 * Return the symbol corresponding to a JVM type descriptor string. 105 * 106 * @param s a JVM type descriptor string 107 * @return the corresponding symbol 108 */ 109 S symbolFrom(String s); 110 111 /** 112 * Return the common supertype descriptor of two type descriptors. 113 * 114 * @param t1 a type descriptor 115 * @param t2 a type descriptor 116 * @return the common supertype descriptor 117 */ 118 T commonSupertype(T t1, T t2); 119 120 /** 121 * Return the type descriptor for the null type. 122 * 123 * @return the type descriptor for the null type 124 */ 125 T nullType(); 126 }