Backward scrolling notmuch_messages_t and notmuch_threads_t

[Sergei Shilovsky]

Lets consider messages first.

As far as I get there is no straightforward
notmuch_messages_move_to_previous. One can usually implement such
behaviour with caching previous messages which is slightly inefficient
in memory consumption terms.

But we can sort messages either date asc or date desc.

Suppose, we're currently at the 1000th message in query "tag:whatever".

So if we need to go to the previous message we could do something like

    notmuch search --sort=oldest-first tag:whatever and \
        date:..<here is the date of the 1000th message>

This query's result should start with our 1000th message following its
previous message (in terms of the original request). So backward
scrolling with no cache looks to be at least possible.

Any idea of would that be fine? Is it possible to implement similar
thing at low-level?

-- 
С уважением,
Сергей Шиловский
Sergei Shilovsky