public static boolean isReceiverType(
PsiType functionalInterfaceType,
PsiClass containingClass,
@Nullable PsiMethod referencedMethod) {
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(functionalInterfaceType);
final MethodSignature function = LambdaUtil.getFunction(resolveResult.getElement());
if (function != null) {
final int interfaceMethodParamsLength = function.getParameterTypes().length;
if (interfaceMethodParamsLength > 0) {
final PsiType firstParamType =
resolveResult.getSubstitutor().substitute(function.getParameterTypes()[0]);
boolean isReceiver =
isReceiverType(
firstParamType,
containingClass,
PsiUtil.resolveGenericsClassInType(firstParamType).getSubstitutor());
if (isReceiver) {
if (referencedMethod == null) {
if (interfaceMethodParamsLength == 1) return true;
return false;
}
if (referencedMethod.getParameterList().getParametersCount()
!= interfaceMethodParamsLength - 1) {
return false;
}
return true;
}
}
}
return false;
}
@Nullable
public static PsiType getFunctionalInterfaceReturnType(
@Nullable PsiType functionalInterfaceType) {
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(functionalInterfaceType);
final PsiClass psiClass = resolveResult.getElement();
if (psiClass != null) {
final MethodSignature methodSignature = getFunction(psiClass);
if (methodSignature != null) {
final PsiType returnType = getReturnType(psiClass, methodSignature);
return resolveResult.getSubstitutor().substitute(returnType);
}
}
return null;
}
@NotNull
public static QualifierResolveResult getQualifierResolveResult(
@NotNull PsiMethodReferenceExpression methodReferenceExpression) {
PsiClass containingClass = null;
PsiSubstitutor substitutor = PsiSubstitutor.EMPTY;
final PsiExpression expression = methodReferenceExpression.getQualifierExpression();
if (expression != null) {
final PsiType expressionType = getExpandedType(expression.getType(), expression);
PsiClassType.ClassResolveResult result = PsiUtil.resolveGenericsClassInType(expressionType);
containingClass = result.getElement();
if (containingClass != null) {
substitutor = result.getSubstitutor();
}
if (containingClass == null && expression instanceof PsiReferenceExpression) {
final JavaResolveResult resolveResult =
((PsiReferenceExpression) expression).advancedResolve(false);
final PsiElement resolve = resolveResult.getElement();
if (resolve instanceof PsiClass) {
containingClass = (PsiClass) resolve;
substitutor = resolveResult.getSubstitutor();
return new QualifierResolveResult(containingClass, substitutor, true);
}
}
} else {
final PsiTypeElement typeElement = methodReferenceExpression.getQualifierType();
if (typeElement != null) {
PsiType type = getExpandedType(typeElement.getType(), typeElement);
PsiClassType.ClassResolveResult result = PsiUtil.resolveGenericsClassInType(type);
containingClass = result.getElement();
if (containingClass != null) {
return new QualifierResolveResult(containingClass, result.getSubstitutor(), true);
}
}
}
return new QualifierResolveResult(containingClass, substitutor, false);
}
@Nullable
public static PsiType getSubstitutedType(@Nullable PsiParameter parameter) {
if (parameter == null) return null;
final PsiType type = getType(parameter);
if (type instanceof PsiArrayType) {
return type;
}
final PsiClassType.ClassResolveResult result = PsiUtil.resolveGenericsClassInType(type);
final PsiClass psiClass = result.getElement();
if (psiClass == null) return type;
final Set<PsiTypeParameter> usedTypeParameters = new HashSet<PsiTypeParameter>();
RefactoringUtil.collectTypeParameters(usedTypeParameters, parameter);
for (Iterator<PsiTypeParameter> iterator = usedTypeParameters.iterator();
iterator.hasNext(); ) {
PsiTypeParameter usedTypeParameter = iterator.next();
if (parameter.getDeclarationScope() != usedTypeParameter.getOwner()) {
iterator.remove();
}
}
PsiSubstitutor subst = PsiSubstitutor.EMPTY;
for (PsiTypeParameter usedTypeParameter : usedTypeParameters) {
subst =
subst.put(usedTypeParameter, TypeConversionUtil.typeParameterErasure(usedTypeParameter));
}
PsiSubstitutor substitutor = PsiSubstitutor.EMPTY;
final Map<PsiTypeParameter, PsiType> typeMap = result.getSubstitutor().getSubstitutionMap();
for (PsiTypeParameter typeParameter : typeMap.keySet()) {
final PsiType psiType = typeMap.get(typeParameter);
substitutor =
substitutor.put(typeParameter, psiType != null ? subst.substitute(psiType) : null);
}
if (psiClass instanceof PsiTypeParameter) {
return subst.substitute((PsiTypeParameter) psiClass);
} else {
return JavaPsiFacade.getElementFactory(parameter.getProject())
.createType(psiClass, substitutor);
}
}
private static PsiType getLambdaParameterFromType(
int parameterIndex, PsiLambdaExpression lambdaExpression, PsiType conjunct) {
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(conjunct);
if (resolveResult != null) {
final PsiMethod method = getFunctionalInterfaceMethod(conjunct);
if (method != null) {
final PsiParameter[] parameters = method.getParameterList().getParameters();
if (parameterIndex < parameters.length) {
final PsiType psiType =
getSubstitutor(method, resolveResult)
.substitute(parameters[parameterIndex].getType());
if (!dependsOnTypeParams(psiType, conjunct, lambdaExpression)) {
return GenericsUtil.eliminateWildcards(psiType);
}
}
}
}
return null;
}
public static boolean isReceiverType(
PsiType receiverType, @Nullable PsiClass containingClass, PsiSubstitutor psiSubstitutor) {
if (containingClass != null) {
receiverType = getExpandedType(receiverType, containingClass);
}
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(receiverType);
final PsiClass receiverClass = resolveResult.getElement();
if (receiverClass != null && isReceiverType(receiverClass, containingClass)) {
if (emptyOrRaw(containingClass, psiSubstitutor)) {
return true;
}
final PsiSubstitutor derivedSubstitutor =
TypeConversionUtil.getClassSubstitutor(containingClass, receiverClass, psiSubstitutor);
return derivedSubstitutor != null
&& TypeConversionUtil.isAssignable(
JavaPsiFacade.getElementFactory(containingClass.getProject())
.createType(containingClass, derivedSubstitutor),
receiverType);
}
return false;
}
private static boolean hasReceiver(
@NotNull PsiMethodReferenceExpression methodRef,
@NotNull PsiMethod method,
PsiType functionalInterfaceType) {
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(functionalInterfaceType);
final PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(resolveResult);
final MethodSignature signature =
interfaceMethod != null
? interfaceMethod.getSignature(
LambdaUtil.getSubstitutor(interfaceMethod, resolveResult))
: null;
if (signature == null) {
return false;
}
final PsiType[] parameterTypes = signature.getParameterTypes();
final QualifierResolveResult qualifierResolveResult = getQualifierResolveResult(methodRef);
return (method.getParameterList().getParametersCount() + 1 == parameterTypes.length
|| method.isVarArgs()
&& parameterTypes.length > 0
&& !method.hasModifierProperty(PsiModifier.STATIC))
&& hasReceiver(parameterTypes, qualifierResolveResult, methodRef);
}
@Override
public boolean reduce(InferenceSession session, List<ConstraintFormula> constraints) {
if (!LambdaUtil.isFunctionalType(myT)) {
return false;
}
final PsiType groundTargetType =
FunctionalInterfaceParameterizationUtil.getGroundTargetType(myT);
final PsiClassType.ClassResolveResult classResolveResult =
PsiUtil.resolveGenericsClassInType(groundTargetType);
final PsiMethod interfaceMethod = LambdaUtil.getFunctionalInterfaceMethod(classResolveResult);
if (interfaceMethod == null) {
return false;
}
final PsiSubstitutor substitutor =
LambdaUtil.getSubstitutor(interfaceMethod, classResolveResult);
final PsiParameter[] targetParameters = interfaceMethod.getParameterList().getParameters();
final PsiType interfaceMethodReturnType = interfaceMethod.getReturnType();
final PsiType returnType = substitutor.substitute(interfaceMethodReturnType);
final PsiType[] typeParameters = myExpression.getTypeParameters();
final PsiMethodReferenceUtil.QualifierResolveResult qualifierResolveResult =
PsiMethodReferenceUtil.getQualifierResolveResult(myExpression);
if (!myExpression.isExact()) {
for (PsiParameter parameter : targetParameters) {
if (!session.isProperType(substitutor.substitute(parameter.getType()))) {
return false;
}
}
} else {
final PsiMember applicableMember = myExpression.getPotentiallyApplicableMember();
LOG.assertTrue(applicableMember != null);
final PsiClass applicableMemberContainingClass = applicableMember.getContainingClass();
final PsiClass containingClass = qualifierResolveResult.getContainingClass();
PsiSubstitutor psiSubstitutor = qualifierResolveResult.getSubstitutor();
psiSubstitutor =
applicableMemberContainingClass == null
|| containingClass == null
|| myExpression.isConstructor()
? psiSubstitutor
: TypeConversionUtil.getSuperClassSubstitutor(
applicableMemberContainingClass, containingClass, psiSubstitutor);
PsiType applicableMethodReturnType =
applicableMember instanceof PsiMethod
? ((PsiMethod) applicableMember).getReturnType()
: null;
int idx = 0;
for (PsiTypeParameter param :
((PsiTypeParameterListOwner) applicableMember).getTypeParameters()) {
if (idx < typeParameters.length) {
psiSubstitutor = psiSubstitutor.put(param, typeParameters[idx++]);
}
}
final PsiParameter[] parameters =
applicableMember instanceof PsiMethod
? ((PsiMethod) applicableMember).getParameterList().getParameters()
: PsiParameter.EMPTY_ARRAY;
if (targetParameters.length == parameters.length + 1) {
specialCase(session, constraints, substitutor, targetParameters, true);
for (int i = 1; i < targetParameters.length; i++) {
constraints.add(
new TypeCompatibilityConstraint(
session.substituteWithInferenceVariables(
psiSubstitutor.substitute(parameters[i - 1].getType())),
substitutor.substitute(targetParameters[i].getType())));
}
} else if (targetParameters.length == parameters.length) {
for (int i = 0; i < targetParameters.length; i++) {
constraints.add(
new TypeCompatibilityConstraint(
session.substituteWithInferenceVariables(
psiSubstitutor.substitute(parameters[i].getType())),
substitutor.substitute(targetParameters[i].getType())));
}
} else {
return false;
}
if (returnType != PsiType.VOID && returnType != null) {
if (applicableMethodReturnType == PsiType.VOID) {
return false;
}
if (applicableMethodReturnType != null) {
constraints.add(
new TypeCompatibilityConstraint(
returnType,
session.substituteWithInferenceVariables(
psiSubstitutor.substitute(applicableMethodReturnType))));
} else if (applicableMember instanceof PsiClass
|| applicableMember instanceof PsiMethod
&& ((PsiMethod) applicableMember).isConstructor()) {
final PsiElementFactory elementFactory =
JavaPsiFacade.getElementFactory(applicableMember.getProject());
if (containingClass != null) {
final PsiType classType =
session.substituteWithInferenceVariables(
elementFactory.createType(containingClass, psiSubstitutor));
constraints.add(new TypeCompatibilityConstraint(returnType, classType));
}
}
}
return true;
}
final Map<PsiElement, PsiType> map = LambdaUtil.getFunctionalTypeMap();
final PsiType added = map.put(myExpression, session.startWithFreshVars(groundTargetType));
final JavaResolveResult resolve;
try {
resolve = myExpression.advancedResolve(true);
} finally {
if (added == null) {
map.remove(myExpression);
}
}
final PsiElement element = resolve.getElement();
if (element == null) {
return false;
}
if (PsiType.VOID.equals(returnType) || returnType == null) {
return true;
}
if (element instanceof PsiMethod) {
final PsiMethod method = (PsiMethod) element;
final PsiType referencedMethodReturnType;
final PsiClass containingClass = method.getContainingClass();
LOG.assertTrue(containingClass != null, method);
PsiClass qContainingClass = qualifierResolveResult.getContainingClass();
PsiSubstitutor psiSubstitutor = qualifierResolveResult.getSubstitutor();
if (qContainingClass != null) {
if (PsiUtil.isRawSubstitutor(qContainingClass, psiSubstitutor)) {
psiSubstitutor = PsiSubstitutor.EMPTY;
}
if (qContainingClass.isInheritor(containingClass, true)) {
psiSubstitutor =
TypeConversionUtil.getClassSubstitutor(
containingClass, qContainingClass, PsiSubstitutor.EMPTY);
LOG.assertTrue(psiSubstitutor != null);
}
}
if (method.isConstructor()) {
referencedMethodReturnType =
JavaPsiFacade.getElementFactory(method.getProject())
.createType(containingClass, PsiSubstitutor.EMPTY);
} else {
referencedMethodReturnType = method.getReturnType();
}
LOG.assertTrue(referencedMethodReturnType != null, method);
if (!PsiTreeUtil.isContextAncestor(containingClass, myExpression, false)
|| PsiUtil.getEnclosingStaticElement(myExpression, containingClass) != null) {
session.initBounds(myExpression, containingClass.getTypeParameters());
}
session.initBounds(myExpression, method.getTypeParameters());
// if i) the method reference elides NonWildTypeArguments,
// ii) the compile-time declaration is a generic method, and
// iii) the return type of the compile-time declaration mentions at least one of the method's
// type parameters;
if (typeParameters.length == 0 && method.getTypeParameters().length > 0) {
final PsiClass interfaceClass = classResolveResult.getElement();
LOG.assertTrue(interfaceClass != null);
if (PsiPolyExpressionUtil.mentionsTypeParameters(
referencedMethodReturnType, ContainerUtil.newHashSet(method.getTypeParameters()))) {
// the constraint reduces to the bound set B3 which would be used to determine the method
// reference's invocation type
// when targeting the return type of the function type, as defined in 18.5.2.
session.collectApplicabilityConstraints(
myExpression, ((MethodCandidateInfo) resolve), groundTargetType);
session.registerReturnTypeConstraints(referencedMethodReturnType, returnType);
return true;
}
}
if (PsiType.VOID.equals(referencedMethodReturnType)) {
return false;
}
int idx = 0;
for (PsiTypeParameter param : method.getTypeParameters()) {
if (idx < typeParameters.length) {
psiSubstitutor = psiSubstitutor.put(param, typeParameters[idx++]);
}
}
final PsiParameter[] parameters = method.getParameterList().getParameters();
if (targetParameters.length == parameters.length + 1
&& !method.isVarArgs()
&& PsiPolyExpressionUtil.mentionsTypeParameters(
referencedMethodReturnType,
ContainerUtil.newHashSet(
containingClass.getTypeParameters()))) { // todo specification bug?
specialCase(session, constraints, substitutor, targetParameters, false);
}
constraints.add(
new TypeCompatibilityConstraint(
returnType,
session.substituteWithInferenceVariables(
psiSubstitutor.substitute(referencedMethodReturnType))));
}
return true;
}
public TypeParamsChecker(PsiElement expression) {
this(
expression,
PsiUtil.resolveGenericsClassInType(getFunctionalInterfaceType(expression, false))
.getElement());
}
@Nullable
public static PsiMethod getFunctionalInterfaceMethod(@Nullable PsiType functionalInterfaceType) {
return getFunctionalInterfaceMethod(
PsiUtil.resolveGenericsClassInType(functionalInterfaceType));
}
@Nullable
public static PsiType getFunctionalInterfaceType(
PsiElement expression, final boolean tryToSubstitute, int paramIdx) {
PsiElement parent = expression.getParent();
PsiElement element = expression;
while (parent instanceof PsiParenthesizedExpression
|| parent instanceof PsiConditionalExpression) {
if (parent instanceof PsiConditionalExpression
&& ((PsiConditionalExpression) parent).getThenExpression() != element
&& ((PsiConditionalExpression) parent).getElseExpression() != element) break;
element = parent;
parent = parent.getParent();
}
if (parent instanceof PsiArrayInitializerExpression) {
final PsiType psiType = ((PsiArrayInitializerExpression) parent).getType();
if (psiType instanceof PsiArrayType) {
return ((PsiArrayType) psiType).getComponentType();
}
} else if (parent instanceof PsiTypeCastExpression) {
final PsiType castType = ((PsiTypeCastExpression) parent).getType();
if (castType instanceof PsiIntersectionType) {
for (PsiType conjunctType : ((PsiIntersectionType) castType).getConjuncts()) {
if (getFunctionalInterfaceMethod(conjunctType) != null) return conjunctType;
}
}
return castType;
} else if (parent instanceof PsiVariable) {
return ((PsiVariable) parent).getType();
} else if (parent instanceof PsiAssignmentExpression
&& expression instanceof PsiExpression
&& !PsiUtil.isOnAssignmentLeftHand((PsiExpression) expression)) {
final PsiExpression lExpression = ((PsiAssignmentExpression) parent).getLExpression();
return lExpression.getType();
} else if (parent instanceof PsiExpressionList) {
final PsiExpressionList expressionList = (PsiExpressionList) parent;
final int lambdaIdx = getLambdaIdx(expressionList, expression);
if (lambdaIdx > -1) {
PsiType cachedType = null;
final Pair<PsiMethod, PsiSubstitutor> method = MethodCandidateInfo.getCurrentMethod(parent);
if (method != null) {
final PsiParameter[] parameters = method.first.getParameterList().getParameters();
cachedType =
lambdaIdx < parameters.length
? method.second.substitute(
getNormalizedType(
parameters[adjustLambdaIdx(lambdaIdx, method.first, parameters)]))
: null;
if (!tryToSubstitute) return cachedType;
}
PsiElement gParent = expressionList.getParent();
if (gParent instanceof PsiAnonymousClass) {
gParent = gParent.getParent();
}
if (gParent instanceof PsiCall) {
final PsiCall contextCall = (PsiCall) gParent;
final JavaResolveResult resolveResult = contextCall.resolveMethodGenerics();
final PsiElement resolve = resolveResult.getElement();
if (resolve instanceof PsiMethod) {
final PsiParameter[] parameters =
((PsiMethod) resolve).getParameterList().getParameters();
final int finalLambdaIdx = adjustLambdaIdx(lambdaIdx, (PsiMethod) resolve, parameters);
if (finalLambdaIdx < parameters.length) {
if (!tryToSubstitute) return getNormalizedType(parameters[finalLambdaIdx]);
if (cachedType != null && paramIdx > -1) {
final PsiMethod interfaceMethod = getFunctionalInterfaceMethod(cachedType);
if (interfaceMethod != null) {
final PsiClassType.ClassResolveResult cachedResult =
PsiUtil.resolveGenericsClassInType(cachedType);
final PsiType interfaceMethodParameterType =
interfaceMethod.getParameterList().getParameters()[paramIdx].getType();
if (!dependsOnTypeParams(
cachedResult.getSubstitutor().substitute(interfaceMethodParameterType),
cachedType,
expression)) {
return cachedType;
}
}
}
return PsiResolveHelper.ourGuard.doPreventingRecursion(
expression,
true,
new Computable<PsiType>() {
@Override
public PsiType compute() {
return resolveResult
.getSubstitutor()
.substitute(getNormalizedType(parameters[finalLambdaIdx]));
}
});
}
}
return null;
}
}
} else if (parent instanceof PsiReturnStatement) {
final PsiLambdaExpression gParent =
PsiTreeUtil.getParentOfType(parent, PsiLambdaExpression.class);
if (gParent != null) {
return getFunctionalInterfaceTypeByContainingLambda(gParent);
} else {
final PsiMethod method = PsiTreeUtil.getParentOfType(parent, PsiMethod.class);
if (method != null) {
return method.getReturnType();
}
}
} else if (parent instanceof PsiLambdaExpression) {
return getFunctionalInterfaceTypeByContainingLambda((PsiLambdaExpression) parent);
}
return null;
}
public static boolean isAcceptable(
PsiLambdaExpression lambdaExpression, final PsiType leftType, boolean checkReturnType) {
if (leftType instanceof PsiIntersectionType) {
for (PsiType conjunctType : ((PsiIntersectionType) leftType).getConjuncts()) {
if (isAcceptable(lambdaExpression, conjunctType, checkReturnType)) return true;
}
return false;
}
final PsiClassType.ClassResolveResult resolveResult =
PsiUtil.resolveGenericsClassInType(GenericsUtil.eliminateWildcards(leftType));
final PsiClass psiClass = resolveResult.getElement();
if (psiClass instanceof PsiAnonymousClass) {
return isAcceptable(
lambdaExpression, ((PsiAnonymousClass) psiClass).getBaseClassType(), checkReturnType);
}
final MethodSignature methodSignature = getFunction(psiClass);
if (methodSignature == null) return false;
final PsiParameter[] lambdaParameters = lambdaExpression.getParameterList().getParameters();
final PsiType[] parameterTypes = methodSignature.getParameterTypes();
if (lambdaParameters.length != parameterTypes.length) return false;
for (int lambdaParamIdx = 0, length = lambdaParameters.length;
lambdaParamIdx < length;
lambdaParamIdx++) {
PsiParameter parameter = lambdaParameters[lambdaParamIdx];
final PsiTypeElement typeElement = parameter.getTypeElement();
if (typeElement != null) {
final PsiType lambdaFormalType = typeElement.getType();
final PsiType methodParameterType = parameterTypes[lambdaParamIdx];
if (lambdaFormalType instanceof PsiPrimitiveType) {
if (methodParameterType instanceof PsiPrimitiveType)
return methodParameterType.equals(lambdaFormalType);
return false;
}
if (!TypeConversionUtil.erasure(lambdaFormalType)
.isAssignableFrom(
TypeConversionUtil.erasure(
GenericsUtil.eliminateWildcards(
resolveResult
.getSubstitutor()
.substitute(
methodSignature
.getSubstitutor()
.substitute(methodParameterType)))))) {
return false;
}
}
}
if (checkReturnType) {
final String uniqueVarName =
JavaCodeStyleManager.getInstance(lambdaExpression.getProject())
.suggestUniqueVariableName("l", lambdaExpression, true);
String canonicalText = leftType.getCanonicalText();
if (leftType instanceof PsiEllipsisType) {
canonicalText = ((PsiEllipsisType) leftType).toArrayType().getCanonicalText();
}
final PsiStatement assignmentFromText =
JavaPsiFacade.getElementFactory(lambdaExpression.getProject())
.createStatementFromText(
canonicalText + " " + uniqueVarName + " = " + lambdaExpression.getText(),
lambdaExpression);
final PsiLocalVariable localVariable =
(PsiLocalVariable)
((PsiDeclarationStatement) assignmentFromText).getDeclaredElements()[0];
LOG.assertTrue(psiClass != null);
PsiType methodReturnType = getReturnType(psiClass, methodSignature);
if (methodReturnType != null) {
methodReturnType =
resolveResult
.getSubstitutor()
.substitute(methodSignature.getSubstitutor().substitute(methodReturnType));
return LambdaHighlightingUtil.checkReturnTypeCompatible(
(PsiLambdaExpression) localVariable.getInitializer(), methodReturnType)
== null;
}
}
return true;
}