@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;
}
@Nullable
@Override
public PsiType getFunctionalInterfaceType() {
return FunctionalInterfaceParameterizationUtil.getGroundTargetType(
LambdaUtil.getFunctionalInterfaceType(this, true), this);
}