public ProjectionErasingJetType(JetType delegate) {
this.delegate = delegate;
arguments = new ArrayList<TypeProjection>();
for (TypeProjection tp : delegate.getArguments()) {
arguments.add(new TypeProjection(Variance.INVARIANT, tp.getType()));
}
}
// Returns list with type arguments info from supertypes
// Example:
// - Foo<A, B> is a subtype of Bar<A, List<B>>, Baz<Boolean, A>
// - input: klass = Foo, typesFromSuper = [Bar<String, List<Int>>, Baz<Boolean, CharSequence>]
// - output[0] = [String, CharSequence], output[1] = []
private static List<List<TypeProjectionAndVariance>> calculateTypeArgumentsFromSuper(
@NotNull ClassDescriptor klass, @NotNull Collection<TypeAndVariance> typesFromSuper) {
// For each superclass of klass and its parameters, hold their mapping to klass' parameters
// #0 of Bar -> A
// #1 of Bar -> List<B>
// #0 of Baz -> Boolean
// #1 of Baz -> A
// #0 of Foo -> A (mapped to itself)
// #1 of Foo -> B (mapped to itself)
Multimap<TypeConstructor, TypeProjection> substitution =
SubstitutionUtils.buildDeepSubstitutionMultimap(
TypeUtils.makeUnsubstitutedType(klass, JetScope.EMPTY));
// for each parameter of klass, hold arguments in corresponding supertypes
List<List<TypeProjectionAndVariance>> parameterToArgumentsFromSuper = Lists.newArrayList();
for (TypeParameterDescriptor ignored : klass.getTypeConstructor().getParameters()) {
parameterToArgumentsFromSuper.add(new ArrayList<TypeProjectionAndVariance>());
}
// Enumerate all types from super and all its parameters
for (TypeAndVariance typeFromSuper : typesFromSuper) {
for (TypeParameterDescriptor parameter :
typeFromSuper.type.getConstructor().getParameters()) {
TypeProjection argument = typeFromSuper.type.getArguments().get(parameter.getIndex());
// for given example, this block is executed four times:
// 1. typeFromSuper = Bar<String, List<Int>>, parameter = "#0 of Bar", argument =
// String
// 2. typeFromSuper = Bar<String, List<Int>>, parameter = "#1 of Bar", argument =
// List<Int>
// 3. typeFromSuper = Baz<Boolean, CharSequence>, parameter = "#0 of Baz", argument =
// Boolean
// 4. typeFromSuper = Baz<Boolean, CharSequence>, parameter = "#1 of Baz", argument =
// CharSequence
// if it is mapped to klass' parameter, then store it into map
for (TypeProjection projection : substitution.get(parameter.getTypeConstructor())) {
// 1. projection = A
// 2. projection = List<B>
// 3. projection = Boolean
// 4. projection = A
ClassifierDescriptor classifier =
projection.getType().getConstructor().getDeclarationDescriptor();
// this condition is true for 1 and 4, false for 2 and 3
if (classifier instanceof TypeParameterDescriptor
&& classifier.getContainingDeclaration() == klass) {
int parameterIndex = ((TypeParameterDescriptor) classifier).getIndex();
Variance effectiveVariance =
parameter.getVariance().superpose(typeFromSuper.varianceOfPosition);
parameterToArgumentsFromSuper
.get(parameterIndex)
.add(new TypeProjectionAndVariance(argument, effectiveVariance));
}
}
}
}
return parameterToArgumentsFromSuper;
}
private void appendTypeProjections(
@NotNull List<TypeProjection> typeProjections, @NotNull StringBuilder builder) {
for (Iterator<TypeProjection> iterator = typeProjections.iterator(); iterator.hasNext(); ) {
TypeProjection typeProjection = iterator.next();
if (typeProjection.getProjectionKind() != Variance.INVARIANT) {
builder.append(typeProjection.getProjectionKind()).append(" ");
}
builder.append(renderType(typeProjection.getType()));
if (iterator.hasNext()) {
builder.append(", ");
}
}
}
private void appendTypeProjections(
StringBuilder result, List<TypeProjection> typeProjections, boolean shortNamesOnly) {
for (Iterator<TypeProjection> iterator = typeProjections.iterator(); iterator.hasNext(); ) {
TypeProjection typeProjection = iterator.next();
if (typeProjection.getProjectionKind() != Variance.INVARIANT) {
result.append(typeProjection.getProjectionKind()).append(" ");
}
result.append(renderType(typeProjection.getType(), shortNamesOnly));
if (iterator.hasNext()) {
result.append(", ");
}
}
}
private Variance calculateArgumentProjectionKindFromSuper(
@NotNull TypeProjection argument,
@NotNull List<TypeProjectionAndVariance> projectionsFromSuper) {
Set<Variance> projectionKindsInSuper = Sets.newLinkedHashSet();
for (TypeProjectionAndVariance projectionAndVariance : projectionsFromSuper) {
projectionKindsInSuper.add(projectionAndVariance.typeProjection.getProjectionKind());
}
Variance defaultProjectionKind = argument.getProjectionKind();
if (projectionKindsInSuper.size() == 0) {
return defaultProjectionKind;
} else if (projectionKindsInSuper.size() == 1) {
Variance projectionKindInSuper = projectionKindsInSuper.iterator().next();
if (defaultProjectionKind == INVARIANT || defaultProjectionKind == projectionKindInSuper) {
return projectionKindInSuper;
} else {
reportError(
"Incompatible projection kinds in type arguments of super methods' return types: "
+ projectionsFromSuper
+ ", defined in current: "
+ argument);
return defaultProjectionKind;
}
} else {
reportError(
"Incompatible projection kinds in type arguments of super methods' return types: "
+ projectionsFromSuper);
return defaultProjectionKind;
}
}
public void serialize(@NotNull JetType type) {
serialize(type.getConstructor().getDeclarationDescriptor());
if (!type.getArguments().isEmpty()) {
sb.append("<");
boolean first = true;
for (TypeProjection proj : type.getArguments()) {
if (!first) {
sb.append(", ");
}
serialize(proj.getProjectionKind());
serialize(proj.getType());
first = false;
}
sb.append(">");
}
if (type.isNullable()) {
sb.append("?");
}
}
@NotNull
public static JetType createCorrespondingExtensionFunctionType(
@NotNull JetType functionType, @NotNull JetType receiverType) {
assert KotlinBuiltIns.getInstance().isFunctionType(functionType);
List<TypeProjection> typeArguments = functionType.getArguments();
assert !typeArguments.isEmpty();
List<JetType> arguments = Lists.newArrayList();
// excluding the last type argument of the function type, which is the return type
int index = 0;
int lastIndex = typeArguments.size() - 1;
for (TypeProjection typeArgument : typeArguments) {
if (index < lastIndex) {
arguments.add(typeArgument.getType());
}
index++;
}
JetType returnType = typeArguments.get(lastIndex).getType();
return KotlinBuiltIns.getInstance()
.getFunctionType(functionType.getAnnotations(), receiverType, arguments, returnType);
}
@NotNull
private List<TypeProjection> getTypeArgsOfType(
@NotNull JetType autoType,
@NotNull ClassifierDescriptor classifier,
@NotNull List<TypeAndVariance> typesFromSuper) {
List<TypeProjection> autoArguments = autoType.getArguments();
if (!(classifier instanceof ClassDescriptor)) {
assert autoArguments.isEmpty()
: "Unexpected type arguments when type constructor is not ClassDescriptor, type = "
+ autoType;
return autoArguments;
}
List<List<TypeProjectionAndVariance>> typeArgumentsFromSuper =
calculateTypeArgumentsFromSuper((ClassDescriptor) classifier, typesFromSuper);
// Modify type arguments using info from typesFromSuper
List<TypeProjection> resultArguments = Lists.newArrayList();
for (TypeParameterDescriptor parameter : classifier.getTypeConstructor().getParameters()) {
TypeProjection argument = autoArguments.get(parameter.getIndex());
JetType argumentType = argument.getType();
List<TypeProjectionAndVariance> projectionsFromSuper =
typeArgumentsFromSuper.get(parameter.getIndex());
List<TypeAndVariance> argTypesFromSuper = getTypes(projectionsFromSuper);
JetType type =
modifyTypeAccordingToSuperMethods(argumentType, argTypesFromSuper, TYPE_ARGUMENT);
Variance projectionKind =
calculateArgumentProjectionKindFromSuper(argument, projectionsFromSuper);
resultArguments.add(new TypeProjection(projectionKind, type));
}
return resultArguments;
}
/**
* Determines what constraint (supertype, subtype or equal) should be generated for type parameter
* {@code T} in a constraint like (in this example subtype one): <br>
* {@code MyClass<in/out/- A> <: MyClass<in/out/- B>}, where {@code MyClass<in/out/- T>} is
* declared. <br>
* The parameters description is given according to the example above.
*
* @param typeParameterVariance declared variance of T
* @param subjectTypeProjection {@code in/out/- A}
* @param constrainingTypeProjection {@code in/out/- B}
* @param upperConstraintKind kind of the constraint {@code MyClass<...A> <: MyClass<...B>}
* (subtype in this example).
* @return kind of constraint to be generated: {@code A <: B} (subtype), {@code A >: B}
* (supertype) or {@code A = B} (equal).
*/
@NotNull
private static ConstraintKind getTypeParameterConstraintKind(
@NotNull Variance typeParameterVariance,
@NotNull TypeProjection subjectTypeProjection,
@NotNull TypeProjection constrainingTypeProjection,
@NotNull ConstraintKind upperConstraintKind) {
// If variance of type parameter is non-trivial, it should be taken into consideration to infer
// result constraint type.
// Otherwise when type parameter declared as INVARIANT, there might be non-trivial use-site
// variance of a supertype.
//
// Example: Let class MyClass<T> is declared.
//
// If super type has 'out' projection:
// MyClass<A> <: MyClass<out B>,
// then constraint A <: B can be generated.
//
// If super type has 'in' projection:
// MyClass<A> <: MyClass<in B>,
// then constraint A >: B can be generated.
//
// Otherwise constraint A = B should be generated.
Variance varianceForTypeParameter;
if (typeParameterVariance != INVARIANT) {
varianceForTypeParameter = typeParameterVariance;
} else if (upperConstraintKind == SUPER_TYPE) {
varianceForTypeParameter = constrainingTypeProjection.getProjectionKind();
} else if (upperConstraintKind == SUB_TYPE) {
varianceForTypeParameter = subjectTypeProjection.getProjectionKind();
} else {
varianceForTypeParameter = INVARIANT;
}
return getTypeParameterConstraintKind(varianceForTypeParameter, upperConstraintKind);
}
public String toString() {
return typeProjection.toString();
}
private void addConstraint(
@NotNull ConstraintKind constraintKind,
@NotNull JetType subjectType,
@Nullable JetType constrainingType,
@NotNull ConstraintPosition constraintPosition) {
if (constrainingType == TypeUtils.NO_EXPECTED_TYPE
|| constrainingType == DONT_CARE
|| constrainingType == CANT_INFER) {
return;
}
if (constrainingType == null
|| (ErrorUtils.isErrorType(constrainingType)
&& constrainingType != PLACEHOLDER_FUNCTION_TYPE)) {
hasErrorInConstrainingTypes = true;
return;
}
assert subjectType != TypeUtils.NO_EXPECTED_TYPE
: "Subject type shouldn't be NO_EXPECTED_TYPE (in position " + constraintPosition + " )";
if (ErrorUtils.isErrorType(subjectType)) return;
DeclarationDescriptor subjectTypeDescriptor =
subjectType.getConstructor().getDeclarationDescriptor();
KotlinBuiltIns kotlinBuiltIns = KotlinBuiltIns.getInstance();
if (constrainingType == PLACEHOLDER_FUNCTION_TYPE) {
if (!kotlinBuiltIns.isFunctionOrExtensionFunctionType(subjectType)) {
if (subjectTypeDescriptor instanceof TypeParameterDescriptor
&& typeParameterConstraints.get(subjectTypeDescriptor) != null) {
// a constraint binds type parameter and any function type, so there is no new info and no
// error
return;
}
errorConstraintPositions.add(constraintPosition);
}
return;
}
// todo temporary hack
// function literal without declaring receiver type { x -> ... }
// can be considered as extension function if one is expected
// (special type constructor for function/ extension function should be introduced like
// PLACEHOLDER_FUNCTION_TYPE)
if (constraintKind == SUB_TYPE
&& kotlinBuiltIns.isFunctionType(constrainingType)
&& kotlinBuiltIns.isExtensionFunctionType(subjectType)) {
constrainingType = createCorrespondingExtensionFunctionType(constrainingType, DONT_CARE);
}
DeclarationDescriptor constrainingTypeDescriptor =
constrainingType.getConstructor().getDeclarationDescriptor();
if (subjectTypeDescriptor instanceof TypeParameterDescriptor) {
TypeParameterDescriptor typeParameter = (TypeParameterDescriptor) subjectTypeDescriptor;
TypeConstraintsImpl typeConstraints = typeParameterConstraints.get(typeParameter);
if (typeConstraints != null) {
if (TypeUtils.dependsOnTypeParameterConstructors(
constrainingType, Collections.singleton(DONT_CARE.getConstructor()))) {
return;
}
if (subjectType.isNullable() && constrainingType.isNullable()) {
constrainingType = TypeUtils.makeNotNullable(constrainingType);
}
typeConstraints.addBound(constraintKind, constrainingType);
return;
}
}
if (constrainingTypeDescriptor instanceof TypeParameterDescriptor) {
assert typeParameterConstraints.get(constrainingTypeDescriptor) == null
: "Constraining type contains type variable " + constrainingTypeDescriptor.getName();
}
if (constraintKind == SUB_TYPE && kotlinBuiltIns.isNothingOrNullableNothing(constrainingType)) {
// following constraints are always true:
// 'Nothing' is a subtype of any type
if (!constrainingType.isNullable()) return;
// 'Nothing?' is a subtype of nullable type
if (subjectType.isNullable()) return;
}
if (!(constrainingTypeDescriptor instanceof ClassDescriptor)
|| !(subjectTypeDescriptor instanceof ClassDescriptor)) {
errorConstraintPositions.add(constraintPosition);
return;
}
switch (constraintKind) {
case SUB_TYPE:
{
if (kotlinBuiltIns.isNothingOrNullableNothing(constrainingType)) break;
JetType correspondingSupertype =
TypeCheckingProcedure.findCorrespondingSupertype(constrainingType, subjectType);
if (correspondingSupertype != null) {
constrainingType = correspondingSupertype;
}
break;
}
case SUPER_TYPE:
{
if (kotlinBuiltIns.isNothingOrNullableNothing(subjectType)) break;
JetType correspondingSupertype =
TypeCheckingProcedure.findCorrespondingSupertype(subjectType, constrainingType);
if (correspondingSupertype != null) {
subjectType = correspondingSupertype;
}
}
case EQUAL: // nothing
}
if (constrainingType.getConstructor() != subjectType.getConstructor()) {
errorConstraintPositions.add(constraintPosition);
return;
}
TypeConstructor typeConstructor = subjectType.getConstructor();
List<TypeProjection> subjectArguments = subjectType.getArguments();
List<TypeProjection> constrainingArguments = constrainingType.getArguments();
List<TypeParameterDescriptor> parameters = typeConstructor.getParameters();
for (int i = 0; i < subjectArguments.size(); i++) {
Variance typeParameterVariance = parameters.get(i).getVariance();
TypeProjection subjectArgument = subjectArguments.get(i);
TypeProjection constrainingArgument = constrainingArguments.get(i);
ConstraintKind typeParameterConstraintKind =
getTypeParameterConstraintKind(
typeParameterVariance, subjectArgument, constrainingArgument, constraintKind);
addConstraint(
typeParameterConstraintKind,
subjectArgument.getType(),
constrainingArgument.getType(),
constraintPosition);
}
}