/*
* Copyright 2000-2013 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.intellij.psi.impl.source.resolve.graphInference;
import com.intellij.openapi.diagnostic.Logger;
import com.intellij.psi.*;
import com.intellij.psi.impl.source.resolve.graphInference.constraints.TypeEqualityConstraint;
import org.jetbrains.annotations.Nullable;
public class FunctionalInterfaceParameterizationUtil {
private static final Logger LOG = Logger.getInstance("#" + FunctionalInterfaceParameterizationUtil.class.getName());
public static boolean isWildcardParameterized(@Nullable PsiType classType) {
if (classType == null) return false;
if (classType instanceof PsiIntersectionType) {
for (PsiType type : ((PsiIntersectionType)classType).getConjuncts()) {
if (!isWildcardParameterized(type)) return false;
}
}
if (classType instanceof PsiClassType) {
for (PsiType type : ((PsiClassType)classType).getParameters()) {
if (type instanceof PsiWildcardType || type instanceof PsiCapturedWildcardType) {
return true;
}
}
return false;
}
LOG.error("Unexpected type: " + classType);
return false;
}
@Nullable
public static PsiType getFunctionalType(@Nullable PsiType psiClassType, PsiLambdaExpression expr) {
return getFunctionalType(psiClassType, expr, true);
}
@Nullable
public static PsiType getFunctionalType(@Nullable PsiType psiClassType, PsiLambdaExpression expr, boolean resolve) {
if (!expr.hasFormalParameterTypes() || expr.getParameterList().getParametersCount() == 0) return psiClassType;
if (!isWildcardParameterized(psiClassType)) {
return psiClassType;
}
final PsiParameter[] lambdaParams = expr.getParameterList().getParameters();
if (psiClassType instanceof PsiIntersectionType) {
for (PsiType psiType : ((PsiIntersectionType)psiClassType).getConjuncts()) {
final PsiType functionalType = getFunctionalType(psiType, expr, false);
if (functionalType != null) return functionalType;
}
return null;
}
LOG.assertTrue(psiClassType instanceof PsiClassType, "Unexpected type: " + psiClassType);
final PsiType[] parameters = ((PsiClassType)psiClassType).getParameters();
final PsiClassType.ClassResolveResult resolveResult = ((PsiClassType)psiClassType).resolveGenerics();
PsiClass psiClass = resolveResult.getElement();
if (psiClass != null) {
final PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(resolveResult);
if (interfaceMethod == null) return null;
final InferenceSession session = new InferenceSession(PsiSubstitutor.EMPTY);
PsiTypeParameter[] typeParameters = psiClass.getTypeParameters();
if (typeParameters.length != parameters.length) {
return null;
}
for (int i = 0; i < typeParameters.length; i++) {
session.addVariable(typeParameters[i], parameters[i]);
}
final PsiElementFactory elementFactory = JavaPsiFacade.getElementFactory(psiClass.getProject());
final PsiParameter[] targetMethodParams = interfaceMethod.getParameterList().getParameters();
for (int i = 0; i < targetMethodParams.length; i++) {
if (resolve) {
session.addConstraint(new TypeEqualityConstraint(lambdaParams[i].getType(), targetMethodParams[i].getType()));
}
}
final PsiClassType parameterization = elementFactory.createType(psiClass, session.infer());
if (!isWildcardParameterized(parameterization)) return parameterization;
}
return null;
}
}