2009/4/3 Rickard Öberg <[email protected]> > Hey, > > While doing the refactoring for the new persistence I want to include > Michaels suggestion to not let ManyAssociation extend the JDK Collection > classes. > > The question then is what semantics to have. I would suggest that a > ManyAssociation is: > * Ordered like a List > * Contains no duplicates like a Set > * Has minimal convenience methods > > Which would result in the following: > public interface ManyAssociation<T> > extends AbstractAssociation > { > int count(); > boolean add(int i, T entity); > boolean remove(T entity); > T get(int i); > > Iterable<T> toIterable(); > List<T> toList(); > Set<T> toSet(); > } > > Points: > * I want to specifically keep down the number of helper methods (isEmpty, > remove(i), add(T) etc.) so that it is easy to add Concerns to it and not > have to implement a whole bunch of various methods. > * Add has index, which makes it possible to use it as a list. > * If you need to use the ManyAssociation with JDK-friendly libraries, use > the "to" methods to create wrappers. The List will have Set semantics > though, as that is how ManyAssociation work, and Set will have List > semantics, as that is how ManyAssociations work. > > Does this make sense? Any missing methods? >
couple of thoughts, you could make it: extends AbstractAssociation, Iterable<T> because Iterable<T> only has one method "iterator()" and you'd then get the benefit of being able to use the many association in a foreach without having to do "toIterable()", which looks a bit clunky also, the wrapper methods should really be called "asList", "asSet", etc. because they return views onto the original object (see "Arrays.asList") rather than copying the contents, while "to..." usually suggests copying > /Rickard > > _______________________________________________ > qi4j-dev mailing list > [email protected] > http://lists.ops4j.org/mailman/listinfo/qi4j-dev > -- Cheers, Stuart
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