Example #1
0
 /**
  * Differs from `isNullableType` only by treating type parameters: acceptsNullable(T) <=> T has
  * nullable lower bound Semantics should be the same as `isSubtype(Nothing?, T)`
  *
  * @return true if `null` can be assigned to storage of this type
  */
 public static boolean acceptsNullable(@NotNull KotlinType type) {
   if (type.isMarkedNullable()) {
     return true;
   }
   if (FlexibleTypesKt.isFlexible(type)
       && acceptsNullable(FlexibleTypesKt.flexibility(type).getUpperBound())) {
     return true;
   }
   return false;
 }
Example #2
0
 /**
  * A work-around of the generic nullability problem in the type checker Semantics should be the
  * same as `!isSubtype(T, Any)`
  *
  * @return true if a value of this type can be null
  */
 public static boolean isNullableType(@NotNull KotlinType type) {
   if (type.isMarkedNullable()) {
     return true;
   }
   if (FlexibleTypesKt.isFlexible(type)
       && isNullableType(FlexibleTypesKt.flexibility(type).getUpperBound())) {
     return true;
   }
   if (isTypeParameter(type)) {
     return hasNullableSuperType(type);
   }
   return false;
 }
  @NotNull
  private TypeProjection unsafeSubstitute(
      @NotNull TypeProjection originalProjection, int recursionDepth) throws SubstitutionException {
    assertRecursionDepth(recursionDepth, originalProjection, substitution);

    if (originalProjection.isStarProjection()) return originalProjection;

    // The type is within the substitution range, i.e. T or T?
    JetType type = originalProjection.getType();
    TypeProjection replacement = substitution.get(type);
    Variance originalProjectionKind = originalProjection.getProjectionKind();
    if (replacement == null
        && FlexibleTypesKt.isFlexible(type)
        && !TypeCapabilitiesKt.isCustomTypeVariable(type)) {
      Flexibility flexibility = FlexibleTypesKt.flexibility(type);
      TypeProjection substitutedLower =
          unsafeSubstitute(
              new TypeProjectionImpl(originalProjectionKind, flexibility.getLowerBound()),
              recursionDepth + 1);
      TypeProjection substitutedUpper =
          unsafeSubstitute(
              new TypeProjectionImpl(originalProjectionKind, flexibility.getUpperBound()),
              recursionDepth + 1);

      Variance substitutedProjectionKind = substitutedLower.getProjectionKind();
      assert (substitutedProjectionKind == substitutedUpper.getProjectionKind())
                  && originalProjectionKind == Variance.INVARIANT
              || originalProjectionKind == substitutedProjectionKind
          : "Unexpected substituted projection kind: "
              + substitutedProjectionKind
              + "; original: "
              + originalProjectionKind;

      JetType substitutedFlexibleType =
          DelegatingFlexibleType.create(
              substitutedLower.getType(),
              substitutedUpper.getType(),
              flexibility.getExtraCapabilities());
      return new TypeProjectionImpl(substitutedProjectionKind, substitutedFlexibleType);
    }

    if (KotlinBuiltIns.isNothing(type) || type.isError()) return originalProjection;

    if (replacement != null) {
      VarianceConflictType varianceConflict =
          conflictType(originalProjectionKind, replacement.getProjectionKind());

      // Captured type might be substituted in an opposite projection:
      // out 'Captured (in Int)' = out Int
      // in 'Captured (out Int)' = in Int
      boolean allowVarianceConflict = CapturedTypeConstructorKt.isCaptured(type);
      if (!allowVarianceConflict) {
        //noinspection EnumSwitchStatementWhichMissesCases
        switch (varianceConflict) {
          case OUT_IN_IN_POSITION:
            throw new SubstitutionException("Out-projection in in-position");
          case IN_IN_OUT_POSITION:
            // todo use the right type parameter variance and upper bound
            return new TypeProjectionImpl(
                Variance.OUT_VARIANCE, type.getConstructor().getBuiltIns().getNullableAnyType());
        }
      }
      JetType substitutedType;
      CustomTypeVariable typeVariable = TypeCapabilitiesKt.getCustomTypeVariable(type);
      if (replacement.isStarProjection()) {
        return replacement;
      } else if (typeVariable != null) {
        substitutedType = typeVariable.substitutionResult(replacement.getType());
      } else {
        // this is a simple type T or T?: if it's T, we should just take replacement, if T? - we
        // make replacement nullable
        substitutedType =
            TypeUtils.makeNullableIfNeeded(replacement.getType(), type.isMarkedNullable());
      }

      // substitutionType.annotations = replacement.annotations ++ type.annotations
      if (!type.getAnnotations().isEmpty()) {
        Annotations typeAnnotations = filterOutUnsafeVariance(type.getAnnotations());
        substitutedType =
            TypeUtilsKt.replaceAnnotations(
                substitutedType,
                new CompositeAnnotations(substitutedType.getAnnotations(), typeAnnotations));
      }

      Variance resultingProjectionKind =
          varianceConflict == VarianceConflictType.NO_CONFLICT
              ? combine(originalProjectionKind, replacement.getProjectionKind())
              : originalProjectionKind;
      return new TypeProjectionImpl(resultingProjectionKind, substitutedType);
    }
    // The type is not within the substitution range, i.e. Foo, Bar<T> etc.
    return substituteCompoundType(originalProjection, recursionDepth);
  }