// 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;
}
@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;
}