| 1 | /* |
|---|---|
| 2 | * Copyright (C) 2007-2010 Júlio Vilmar Gesser. |
| 3 | * Copyright (C) 2011, 2013-2020 The JavaParser Team. |
| 4 | * |
| 5 | * This file is part of JavaParser. |
| 6 | * |
| 7 | * JavaParser can be used either under the terms of |
| 8 | * a) the GNU Lesser General Public License as published by |
| 9 | * the Free Software Foundation, either version 3 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * b) the terms of the Apache License |
| 12 | * |
| 13 | * You should have received a copy of both licenses in LICENCE.LGPL and |
| 14 | * LICENCE.APACHE. Please refer to those files for details. |
| 15 | * |
| 16 | * JavaParser is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU Lesser General Public License for more details. |
| 20 | */ |
| 21 | |
| 22 | package com.github.javaparser.ast.nodeTypes; |
| 23 | |
| 24 | import com.github.javaparser.ast.Node; |
| 25 | import com.github.javaparser.ast.NodeList; |
| 26 | import com.github.javaparser.ast.body.VariableDeclarator; |
| 27 | import com.github.javaparser.ast.type.ArrayType; |
| 28 | import com.github.javaparser.ast.type.Type; |
| 29 | import com.github.javaparser.metamodel.DerivedProperty; |
| 30 | |
| 31 | import java.util.List; |
| 32 | import java.util.Optional; |
| 33 | import java.util.stream.Collectors; |
| 34 | |
| 35 | /** |
| 36 | * A node which has a list of variables. |
| 37 | */ |
| 38 | public interface NodeWithVariables<N extends Node> { |
| 39 | NodeList<VariableDeclarator> getVariables(); |
| 40 | |
| 41 | N setVariables(NodeList<VariableDeclarator> variables); |
| 42 | |
| 43 | default VariableDeclarator getVariable(int i) { |
| 44 | return getVariables().get(i); |
| 45 | } |
| 46 | |
| 47 | @SuppressWarnings("unchecked") |
| 48 | default N setVariable(int i, VariableDeclarator variableDeclarator) { |
| 49 | getVariables().set(i, variableDeclarator); |
| 50 | return (N) this; |
| 51 | } |
| 52 | |
| 53 | @SuppressWarnings("unchecked") |
| 54 | default N addVariable(VariableDeclarator variableDeclarator) { |
| 55 | getVariables().add(variableDeclarator); |
| 56 | return (N) this; |
| 57 | } |
| 58 | |
| 59 | /** |
| 60 | * Returns the type that is shared between all variables. |
| 61 | * This is a shortcut for when you are certain that all variables share one type. |
| 62 | * What makes this difficult is arrays, and being able to set the type. |
| 63 | * <br>For {@code int a;} this is int. |
| 64 | * <br>For {@code int a,b,c,d;} this is also int. |
| 65 | * <br>For {@code int a,b[],c;} this is an assertion error since b is an int[], not an int. |
| 66 | * <br>For {@code int a,b;}, then doing setType(String) on b, this is an assertion error. It is also a situation that you don't really want. |
| 67 | */ |
| 68 | default Type getCommonType() { |
| 69 | NodeList<VariableDeclarator> variables = getVariables(); |
| 70 | if (variables.isEmpty()) { |
| 71 | throw new AssertionError("There is no common type since there are no variables."); |
| 72 | } |
| 73 | Type type = variables.get(0).getType(); |
| 74 | for (int i = 1; i < variables.size(); i++) { |
| 75 | if (!variables.get(i).getType().equals(type)) { |
| 76 | throw new AssertionError("The variables do not have a common type."); |
| 77 | } |
| 78 | } |
| 79 | return type; |
| 80 | } |
| 81 | |
| 82 | /** |
| 83 | * Returns the element type. |
| 84 | * <br>For {@code int a;} this is int. |
| 85 | * <br>For {@code int a,b,c,d;} this is also int. |
| 86 | * <br>For {@code int a,b[],c;} this is also int. Note: no mention of b being an array. |
| 87 | * <br>For {@code int a,b;}, then doing setType(String) on b, then calling getElementType(). This is an assertion error. It is also a situation that you don't really want. |
| 88 | */ |
| 89 | default Type getElementType() { |
| 90 | NodeList<VariableDeclarator> variables = getVariables(); |
| 91 | if (variables.isEmpty()) { |
| 92 | throw new AssertionError("There is no element type since there are no variables."); |
| 93 | } |
| 94 | Type type = variables.get(0).getType().getElementType(); |
| 95 | for (int i = 1; i < variables.size(); i++) { |
| 96 | if (!variables.get(i).getType().getElementType().equals(type)) { |
| 97 | throw new AssertionError("The variables do not have a common type."); |
| 98 | } |
| 99 | } |
| 100 | return type; |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Sets the type of all variables. |
| 105 | * Erases any existing type. |
| 106 | * This is a shortcut for setting a type on all variable declarators separately. |
| 107 | */ |
| 108 | @SuppressWarnings("unchecked") |
| 109 | default N setAllTypes(Type newType) { |
| 110 | for (VariableDeclarator variable : getVariables()) { |
| 111 | variable.setType(newType); |
| 112 | } |
| 113 | return (N) this; |
| 114 | } |
| 115 | |
| 116 | /** |
| 117 | * Returns the type that maximum shared type between all variables. |
| 118 | * The minimum common type does never include annotations on the array level. |
| 119 | * <p> |
| 120 | * <br>For {@code int a;} this is int. |
| 121 | * <br>For {@code int a,b,c,d;} this is also int. |
| 122 | * <br>For {@code int a,b[],c;} this is also int. |
| 123 | * <br>For {@code int[] a[][],b[],c[][];} this is int[][]. |
| 124 | */ |
| 125 | @DerivedProperty |
| 126 | default Optional<Type> getMaximumCommonType() { |
| 127 | return calculateMaximumCommonType(getVariables().stream().map(v -> v.getType()).collect(Collectors.toList())); |
| 128 | } |
| 129 | |
| 130 | static Optional<Type> calculateMaximumCommonType(List<Type> types) { |
| 131 | // we use a local class because we cannot use an helper static method in an interface |
| 132 | class Helper { |
| 133 | // Conceptually: given a type we start from the Element Type and get as many array levels as indicated |
| 134 | // From the implementation point of view we start from the actual type and we remove how many array |
| 135 | // levels as needed to get the target level of arrays |
| 136 | // It returns null if the type has less array levels then the desired target |
| 137 | private Optional<Type> toArrayLevel(Type type, int level) { |
| 138 | if (level > type.getArrayLevel()) { |
| 139 | return Optional.empty(); |
| 140 | } |
| 141 | for (int i = type.getArrayLevel(); i > level; i--) { |
| 142 | if (!(type instanceof ArrayType)) { |
| 143 | return Optional.empty(); |
| 144 | } |
| 145 | type = ((ArrayType) type).getComponentType(); |
| 146 | } |
| 147 | return Optional.of(type); |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | Helper helper = new Helper(); |
| 152 | int level = 0; |
| 153 | boolean keepGoing = true; |
| 154 | // In practice we want to check for how many levels of arrays all the variables have the same type, |
| 155 | // including also the annotations |
| 156 | while (keepGoing) { |
| 157 | final int currentLevel = level; |
| 158 | // Now, given that equality on nodes consider the position the simplest way is to compare |
| 159 | // the pretty-printed string got for a node. We just check all them are the same and if they |
| 160 | // are we just just is not null |
| 161 | Object[] values = types.stream().map(v -> { |
| 162 | Optional<Type> t = helper.toArrayLevel(v, currentLevel); |
| 163 | return t.map(Node::toString).orElse(null); |
| 164 | }).distinct().toArray(); |
| 165 | if (values.length == 1 && values[0] != null) { |
| 166 | level++; |
| 167 | } else { |
| 168 | keepGoing = false; |
| 169 | } |
| 170 | } |
| 171 | return helper.toArrayLevel(types.get(0), --level); |
| 172 | } |
| 173 | |
| 174 | } |
| 175 |
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