@Nullable
public static List<ValueParameterDescriptor> getSubstitutedValueParameters(
FunctionDescriptor substitutedDescriptor,
@NotNull FunctionDescriptor functionDescriptor,
@NotNull TypeSubstitutor substitutor) {
List<ValueParameterDescriptor> result = new ArrayList<ValueParameterDescriptor>();
List<ValueParameterDescriptor> unsubstitutedValueParameters =
functionDescriptor.getValueParameters();
for (int i = 0, unsubstitutedValueParametersSize = unsubstitutedValueParameters.size();
i < unsubstitutedValueParametersSize;
i++) {
ValueParameterDescriptor unsubstitutedValueParameter = unsubstitutedValueParameters.get(i);
// TODO : Lazy?
JetType substitutedType =
substitutor.substitute(unsubstitutedValueParameter.getType(), Variance.IN_VARIANCE);
JetType varargElementType = unsubstitutedValueParameter.getVarargElementType();
JetType substituteVarargElementType =
varargElementType == null
? null
: substitutor.substitute(varargElementType, Variance.IN_VARIANCE);
if (substitutedType == null) return null;
result.add(
new ValueParameterDescriptorImpl(
substitutedDescriptor,
unsubstitutedValueParameter,
unsubstitutedValueParameter.getAnnotations(),
unsubstitutedValueParameter.isVar(),
substitutedType,
substituteVarargElementType));
}
return result;
}
private TypeSubstitutor createTypeSubstitutorWithDefaultForUnknownTypeParameter(
@Nullable final TypeProjection defaultTypeProjection) {
return TypeSubstitutor.create(
new TypeSubstitution() {
@Override
public TypeProjection get(TypeConstructor key) {
DeclarationDescriptor declarationDescriptor = key.getDeclarationDescriptor();
if (declarationDescriptor instanceof TypeParameterDescriptor) {
TypeParameterDescriptor descriptor = (TypeParameterDescriptor) declarationDescriptor;
JetType value = ConstraintsUtil.getValue(getTypeConstraints(descriptor));
if (value != null
&& !TypeUtils.dependsOnTypeParameterConstructors(
value, Collections.singleton(DONT_CARE.getConstructor()))) {
return new TypeProjection(value);
}
if (typeParameterConstraints.containsKey(descriptor)) {
return defaultTypeProjection;
}
}
return null;
}
@Override
public boolean isEmpty() {
return false;
}
@Override
public String toString() {
return typeParameterConstraints.toString();
}
});
}
@Nullable
public static FunctionDescriptor substituteFunctionDescriptor(
@NotNull List<JetType> typeArguments, @NotNull FunctionDescriptor functionDescriptor) {
Map<TypeConstructor, TypeProjection> substitutionContext =
createSubstitutionContext(functionDescriptor, typeArguments);
return functionDescriptor.substitute(TypeSubstitutor.create(substitutionContext));
}
@NotNull
private static FunctionDescriptor substituteSuperFunction(
@NotNull Map<ClassDescriptor, JetType> superclassToSupertype,
@NotNull FunctionDescriptor superFun) {
DeclarationDescriptor superFunContainer = superFun.getContainingDeclaration();
assert superFunContainer instanceof ClassDescriptor : superFunContainer;
JetType supertype = superclassToSupertype.get(superFunContainer);
assert supertype != null : "Couldn't find super type for super function: " + superFun;
TypeSubstitutor supertypeSubstitutor = TypeSubstitutor.create(supertype);
FunctionDescriptor substitutedSuperFun = superFun.substitute(supertypeSubstitutor);
assert substitutedSuperFun != null;
return substitutedSuperFun;
}
/**
* Remember that we are trying to cast something of type {@code supertype} to {@code subtype}.
*
* <p>Since at runtime we can only check the class (type constructor), the rest of the subtype
* should be known statically, from supertype. This method reconstructs all static information
* that can be obtained from supertype.
*
* <p>Example 1: supertype = Collection<String> subtype = List<...> result = List<String>, all
* arguments are inferred
*
* <p>Example 2: supertype = Any subtype = List<...> result = List<*>, some arguments were not
* inferred, replaced with '*'
*/
public static TypeReconstructionResult findStaticallyKnownSubtype(
@NotNull JetType supertype, @NotNull TypeConstructor subtypeConstructor) {
assert !supertype.isNullable() : "This method only makes sense for non-nullable types";
// Assume we are casting an expression of type Collection<Foo> to List<Bar>
// First, let's make List<T>, where T is a type variable
ClassifierDescriptor descriptor = subtypeConstructor.getDeclarationDescriptor();
assert descriptor != null : "Can't create default type for " + subtypeConstructor;
JetType subtypeWithVariables = descriptor.getDefaultType();
// Now, let's find a supertype of List<T> that is a Collection of something,
// in this case it will be Collection<T>
JetType supertypeWithVariables =
TypeCheckingProcedure.findCorrespondingSupertype(subtypeWithVariables, supertype);
final List<TypeParameterDescriptor> variables =
subtypeWithVariables.getConstructor().getParameters();
Map<TypeConstructor, TypeProjection> substitution;
if (supertypeWithVariables != null) {
// Now, let's try to unify Collection<T> and Collection<Foo> solution is a map from T to Foo
TypeUnifier.UnificationResult solution =
TypeUnifier.unify(
new TypeProjectionImpl(supertype),
new TypeProjectionImpl(supertypeWithVariables),
new Predicate<TypeConstructor>() {
@Override
public boolean apply(TypeConstructor typeConstructor) {
ClassifierDescriptor descriptor = typeConstructor.getDeclarationDescriptor();
return descriptor instanceof TypeParameterDescriptor
&& variables.contains(descriptor);
}
});
substitution = Maps.newHashMap(solution.getSubstitution());
} else {
// If there's no corresponding supertype, no variables are determined
// This may be OK, e.g. in case 'Any as List<*>'
substitution = Maps.newHashMapWithExpectedSize(variables.size());
}
// If some of the parameters are not determined by unification, it means that these parameters
// are lost,
// let's put stars instead, so that we can only cast to something like List<*>, e.g. (a: Any) as
// List<*>
boolean allArgumentsInferred = true;
for (TypeParameterDescriptor variable : variables) {
TypeProjection value = substitution.get(variable.getTypeConstructor());
if (value == null) {
substitution.put(
variable.getTypeConstructor(), SubstitutionUtils.makeStarProjection(variable));
allArgumentsInferred = false;
}
}
// At this point we have values for all type parameters of List
// Let's make a type by substituting them: List<T> -> List<Foo>
JetType substituted =
TypeSubstitutor.create(substitution).substitute(subtypeWithVariables, Variance.INVARIANT);
return new TypeReconstructionResult(substituted, allArgumentsInferred);
}
public class FunctionDescriptorUtil {
private static final TypeSubstitutor MAKE_TYPE_PARAMETERS_FRESH =
TypeSubstitutor.create(
new TypeSubstitution() {
@Override
public TypeProjection get(TypeConstructor key) {
return null;
}
@Override
public boolean isEmpty() {
return false;
}
@Override
public String toString() {
return "FunctionDescriptorUtil.MAKE_TYPE_PARAMETERS_FRESH";
}
});
public static Map<TypeConstructor, TypeProjection> createSubstitutionContext(
@NotNull FunctionDescriptor functionDescriptor, List<JetType> typeArguments) {
if (functionDescriptor.getTypeParameters().isEmpty()) return Collections.emptyMap();
Map<TypeConstructor, TypeProjection> result = new HashMap<TypeConstructor, TypeProjection>();
int typeArgumentsSize = typeArguments.size();
List<TypeParameterDescriptor> typeParameters = functionDescriptor.getTypeParameters();
assert typeArgumentsSize == typeParameters.size();
for (int i = 0; i < typeArgumentsSize; i++) {
TypeParameterDescriptor typeParameterDescriptor = typeParameters.get(i);
JetType typeArgument = typeArguments.get(i);
result.put(typeParameterDescriptor.getTypeConstructor(), new TypeProjection(typeArgument));
}
return result;
}
@Nullable
public static List<ValueParameterDescriptor> getSubstitutedValueParameters(
FunctionDescriptor substitutedDescriptor,
@NotNull FunctionDescriptor functionDescriptor,
@NotNull TypeSubstitutor substitutor) {
List<ValueParameterDescriptor> result = new ArrayList<ValueParameterDescriptor>();
List<ValueParameterDescriptor> unsubstitutedValueParameters =
functionDescriptor.getValueParameters();
for (int i = 0, unsubstitutedValueParametersSize = unsubstitutedValueParameters.size();
i < unsubstitutedValueParametersSize;
i++) {
ValueParameterDescriptor unsubstitutedValueParameter = unsubstitutedValueParameters.get(i);
// TODO : Lazy?
JetType substitutedType =
substitutor.substitute(unsubstitutedValueParameter.getType(), Variance.IN_VARIANCE);
JetType varargElementType = unsubstitutedValueParameter.getVarargElementType();
JetType substituteVarargElementType =
varargElementType == null
? null
: substitutor.substitute(varargElementType, Variance.IN_VARIANCE);
if (substitutedType == null) return null;
result.add(
new ValueParameterDescriptorImpl(
substitutedDescriptor,
unsubstitutedValueParameter,
unsubstitutedValueParameter.getAnnotations(),
unsubstitutedValueParameter.isVar(),
substitutedType,
substituteVarargElementType));
}
return result;
}
@Nullable
public static JetType getSubstitutedReturnType(
@NotNull FunctionDescriptor functionDescriptor, TypeSubstitutor substitutor) {
return substitutor.substitute(functionDescriptor.getReturnType(), Variance.OUT_VARIANCE);
}
@Nullable
public static FunctionDescriptor substituteFunctionDescriptor(
@NotNull List<JetType> typeArguments, @NotNull FunctionDescriptor functionDescriptor) {
Map<TypeConstructor, TypeProjection> substitutionContext =
createSubstitutionContext(functionDescriptor, typeArguments);
return functionDescriptor.substitute(TypeSubstitutor.create(substitutionContext));
}
@NotNull
public static JetScope getFunctionInnerScope(
@NotNull JetScope outerScope,
@NotNull FunctionDescriptor descriptor,
@NotNull BindingTrace trace) {
WritableScope parameterScope =
new WritableScopeImpl(
outerScope,
descriptor,
new TraceBasedRedeclarationHandler(trace),
"Function inner scope");
ReceiverParameterDescriptor receiver = descriptor.getReceiverParameter();
if (receiver != null) {
parameterScope.setImplicitReceiver(receiver);
}
for (TypeParameterDescriptor typeParameter : descriptor.getTypeParameters()) {
parameterScope.addTypeParameterDescriptor(typeParameter);
}
for (ValueParameterDescriptor valueParameterDescriptor : descriptor.getValueParameters()) {
parameterScope.addVariableDescriptor(valueParameterDescriptor);
}
parameterScope.addLabeledDeclaration(descriptor);
parameterScope.changeLockLevel(WritableScope.LockLevel.READING);
return parameterScope;
}
public static void initializeFromFunctionType(
@NotNull FunctionDescriptorImpl functionDescriptor,
@NotNull JetType functionType,
@Nullable ReceiverParameterDescriptor expectedThisObject,
@NotNull Modality modality,
@NotNull Visibility visibility) {
assert KotlinBuiltIns.getInstance().isFunctionOrExtensionFunctionType(functionType);
functionDescriptor.initialize(
KotlinBuiltIns.getInstance().getReceiverType(functionType),
expectedThisObject,
Collections.<TypeParameterDescriptorImpl>emptyList(),
KotlinBuiltIns.getInstance().getValueParameters(functionDescriptor, functionType),
KotlinBuiltIns.getInstance().getReturnTypeFromFunctionType(functionType),
modality,
visibility);
}
public static <D extends CallableDescriptor> D alphaConvertTypeParameters(D candidate) {
return (D) candidate.substitute(MAKE_TYPE_PARAMETERS_FRESH);
}
public static FunctionDescriptor getInvokeFunction(@NotNull JetType functionType) {
assert KotlinBuiltIns.getInstance().isFunctionOrExtensionFunctionType(functionType);
ClassifierDescriptor classDescriptorForFunction =
functionType.getConstructor().getDeclarationDescriptor();
assert classDescriptorForFunction instanceof ClassDescriptor;
Collection<FunctionDescriptor> invokeFunctions =
((ClassDescriptor) classDescriptorForFunction)
.getMemberScope(functionType.getArguments())
.getFunctions(Name.identifier("invoke"));
assert invokeFunctions.size() == 1;
return invokeFunctions.iterator().next();
}
}
@Nullable
public static JetType getSubstitutedReturnType(
@NotNull FunctionDescriptor functionDescriptor, TypeSubstitutor substitutor) {
return substitutor.substitute(functionDescriptor.getReturnType(), Variance.OUT_VARIANCE);
}