Cursor(Raw)Result: shouldn't they implement the Iterator interface instead of the Iterable interface?

[christian-lechner]

Hello!

I'm currently working with CursorResult and CursorRawResult classes. Both of them implement the Iterable interface, enabling us to iterate more than once over the result.

However, the iterator method returns always the same iterator and thus the result can only be consumed once.

@Override
public Iterator<T> iterator() {
        if (iter == null) {
            iter = new CursorIterator();
        }
        return iter;
    }

It makes perfectly sense that the result can only be consumed once, because the cursor of the DB is also moved with continueQuery method. One could aggregate the results instead of overwriting it and always provide a new iterator. But the list can grow huge and there is also the asList method.

Wouldn't it be more clear for the user if CursorResult and CursorRawResult would implement the Iterator interface, indicating that it can only be consumed once?

And the asList method returns only a complete list if no object is already consumed from the iterator. Should the asList method be called asListRemaining just like the forEachRemaining of the Iterator interface? Or completely remove this method to avoid confusing?

[mvollmary]

Thanks for your feedback. This is a really good point.

Currently we rewrite the Java Driver. It gets a new api, async and VelocyPack/VelocyStream under the hood.
I already changed the implementation of our new cursor with your input. (which your can find here)

The new driver version will probably be released by the end of the month, but you can already try it out. (Branch 4.0)
Your feedback is much appreciated.

[christian-lechner]

Awesome! New driver looks great, looking forward to it. I will switch to the new version in my new project.

4.0 driver version needs ArangoDB 3.1. Can you tell me when ArangoDB 3.1 will be released?

[mvollmary]

We will release the first beta by the beginning of october, at this time we will release the driver in version 4.0.0 too.

[christian-lechner]

Thank you!