org.sonar.java.resolve.TypeSubstitution.java Source code

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Here is the source code for org.sonar.java.resolve.TypeSubstitution.java

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/*
 * SonarQube Java
 * Copyright (C) 2012-2017 SonarSource SA
 * mailto:info AT sonarsource DOT com
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */
package org.sonar.java.resolve;

import com.google.common.collect.Lists;
import com.google.common.collect.Maps;

import javax.annotation.CheckForNull;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

public class TypeSubstitution {
    private LinkedHashMap<TypeVariableJavaType, JavaType> substitutions = Maps.newLinkedHashMap();

    public TypeSubstitution() {
        // default behavior
    }

    public TypeSubstitution(TypeSubstitution typeSubstitution) {
        // copy the substitution
        this.substitutions = Maps.newLinkedHashMap(typeSubstitution.substitutions);
    }

    @CheckForNull
    public JavaType substitutedType(JavaType javaType) {
        return substitutions.get(javaType);
    }

    public List<TypeVariableJavaType> typeVariables() {
        return Lists.newArrayList(substitutions.keySet());
    }

    public List<Map.Entry<TypeVariableJavaType, JavaType>> substitutionEntries() {
        return Lists.newArrayList(substitutions.entrySet());
    }

    public List<JavaType> substitutedTypes() {
        return Lists.newArrayList(substitutions.values());
    }

    public TypeSubstitution add(TypeVariableJavaType typeVariableType, JavaType javaType) {
        substitutions.put(typeVariableType, javaType.isPrimitive() ? javaType.primitiveWrapperType() : javaType);
        return this;
    }

    public int size() {
        return substitutions.size();
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        } else if (obj == null || getClass() != obj.getClass()) {
            return false;
        } else {
            TypeSubstitution newSubstitution = (TypeSubstitution) obj;

            // take order of entries into account
            return substitutions.equals(newSubstitution.substitutions)
                    && this.substitutionEntries().equals(newSubstitution.substitutionEntries());
        }
    }

    @Override
    public int hashCode() {
        return this.substitutionEntries().hashCode();
    }

    public boolean isIdentity() {
        return substitutionEntries().stream().noneMatch(s -> s.getKey() != s.getValue());
    }

    /**
     * Produce new substitution based on two substitutions using the same keys.
     * if this.substitution is: A -> S, B -> I and source.substitution is : A -> Y, B -> X,
     * produces Y -> S, X -> I
     * @param source the substitution which values will be used as keys.
     * @return combination of the two substitutions.
     */
    public TypeSubstitution combine(TypeSubstitution source) {
        TypeSubstitution result = new TypeSubstitution();
        for (Map.Entry<TypeVariableJavaType, JavaType> substitution : substitutionEntries()) {
            TypeVariableJavaType typeVar = substitution.getKey();
            JavaType targetType = filterWildcard(substitution.getValue());
            JavaType substitutedType = source.substitutedType(typeVar);
            if (substitutedType == null || targetType == substitutedType) {
                result.add(typeVar, targetType);
                continue;
            }
            substitutedType = filterWildcard(substitutedType);
            if (targetType.isArray() && substitutedType.isArray()) {
                targetType = elementType(targetType);
                substitutedType = elementType(substitutedType);
            }
            if (targetType.isTagged(JavaType.TYPEVAR)) {
                result.add((TypeVariableJavaType) targetType, substitutedType);
            } else if (targetType.isParameterized() && substitutedType.isParameterized()) {
                TypeSubstitution combined = ((ParametrizedTypeJavaType) targetType).typeSubstitution
                        .combine(((ParametrizedTypeJavaType) substitutedType).typeSubstitution);
                result.substitutions.putAll(combined.substitutions);
            } else {
                result.add(typeVar, targetType);
            }
        }
        return result;
    }

    private static JavaType filterWildcard(JavaType javaType) {
        if (javaType.isTagged(JavaType.WILDCARD)) {
            return ((WildCardType) javaType).bound;
        }
        return javaType;
    }

    private static JavaType elementType(JavaType javaType) {
        if (javaType.isArray()) {
            return elementType(((ArrayJavaType) javaType).elementType);
        }
        return javaType;
    }
}