Jörn Kottmann wrote:
> Marshall Schor wrote:
>> A user had written this:
>>
>> public static <T extends Annotation> Iterator<T> annotationsIterator(
>> JCas aJCas, int type) {
>> return aJCas.getAnnotationIndex(type).iterator(); // fails, cannot
>> convert from FSIterator<AnnotationFS> to Iterator<T>
>> }
>>
>> This compile-time error can be eliminated by changing the generification
>> of AnnotationIndex as follows:
>>
>> Currently AnnotationIndex is defined:
>> public interface AnnotationIndex extends FSIndex<AnnotationFS>
>>
>> If the definition is changed to:
>> public interface AnnotationIndex <T extends AnnotationBaseFS> extends
>> FSIndex<T>
>> then the user's code above no longer gives a compile-time error. (It
>> does give a warning though - an unchecked conversion is needed).
>>
>> This change makes AnnotationIndex, itself, a generic type, with a type
>> parameter indicating the type the index is over.
>>
>> Is this a correct improvement?
>>
> In my opinion it must be
>
> public interface AnnotationIndex <T extends AnnotationFS> extends
> FSIndex<T>
>
> because the AnnotationIndex interface promises to only contain
> uima.tcas.Annotations and if T extends AnnotationBaseFS it could
> be somthing else, right ?
Yes, AnnotationBaseFS has no built-in support in UIMA, afaik. The
annotation indexes only work on AnnotationFSs.
BTW, I'm getting a "unnecessary cast" warning on line 169 of
AnnotationIndexImpl, in case anybody goes in there to make those
changes.
--Thilo
>
> Jörn
>
>
