On Wed, Aug 12, 2009 at 5:36 AM, Jörn Kottmann<kottm...@gmail.com> wrote:
> Jörn Kottmann wrote:
>>
>> Marshall Schor wrote:
>>>
>>> I'll probably stop trying to convince others if they continue to feel
>>> that the tradeoffs here should be in the direction of returning only
>>> specific types (disallowing users from specifying downcasting in that
>>> manner), versus using types of the form T extends X,
>>> which allows users to specify downcasting.
>>>
>>
>> The case of FSIndexRepository is maybe more clear
>> then the other cases in our API.
>>
>> With down casting it could be changed to
>>
>> interface FSIndexRepository {
>> <T extends FeatureStructure> FSIndex<T> getIndex(String label);
>> <T extends FeatureStructure> FSIterator<T> getAllIndexedFS(Type aType);
>> ...
>> }
>>
>> and then a user could write
>>
>> FSIndex<AnnotationFS> index = repo.getIndex(...);
>> FSIterator<AnnotationFS> it = repo.getAllIndexedFS(...);
>
> Any opinions on this ? Right now the class is not generified but I
> would like to change that before the release.
>I say no since like our other discussions, I don't like cases where there's no guarantee of correctness. A user can write: FSIterator<AnnotationFS> it = repo.getAllIndexedFS(someNonAnnotationTypeCode); and it would compile even though it doesn't make sense. Something like this for JCas, on the other hand, does make sense to me: FSIterator<T extends TOP> getAllIndexedFS(Class<T> jcasType) which is called like FSIterator<MyAnnotationType> it = jcas.getAllIndexedFS(MyAnnotationType.class); -Adam
