/**
* Validates that a type is extendable, i.e. is not an array, a primitive type or a {@code final}
* type.
*
* @param typeDescription The type to validate.
* @param <T> The actual type of the validated instance.
* @return The input value.
*/
public static <T extends GenericTypeDescription> T isExtendable(T typeDescription) {
if (!EXTENDABLE_TYPES.contains(typeDescription.getSort())) {
throw new IllegalArgumentException("Cannot extend generic type: " + typeDescription);
} else if (isDefineable(typeDescription.asErasure()).isFinal()) {
throw new IllegalArgumentException("Cannot extend a final type: " + typeDescription);
}
return typeDescription;
}
/**
* Joins two collections where the left collection must only contain unique elements. If two
* elements represent the same type erasure but are not equal, an exception is thrown-
*
* @param left The left collection.
* @param right The right collection.
* @param <T> The element type.
* @return A joined list of both given lists.
*/
public static <T extends GenericTypeDescription> List<T> joinUniqueRaw(
Collection<? extends T> left, Collection<? extends T> right) {
List<T> result = new ArrayList<T>(left.size() + right.size());
Map<TypeDescription, GenericTypeDescription> types =
new HashMap<TypeDescription, GenericTypeDescription>();
for (T typeDescription : left) {
types.put(typeDescription.asErasure(), typeDescription);
result.add(typeDescription);
}
for (T typeDescription : right) {
GenericTypeDescription conflictingType =
types.put(typeDescription.asErasure(), typeDescription);
if (conflictingType != null && !conflictingType.equals(typeDescription)) {
throw new IllegalArgumentException(
"Conflicting type erasures: " + conflictingType + " and " + typeDescription);
} else if (conflictingType == null) {
result.add(typeDescription);
}
}
return result;
}