Re: [PATCH 0/6] API for iterating over all messages in a thread

[Austin Clements <amdragon@MIT.EDU>]

Quoth Mark Walters on Nov 25 at  2:31 pm:
> 
> Hi
> 
> This series looks good to me (I have not reviewed the two bindings
> patches). Patch 2 looks like it makes things much easier to follow than
> the current code (if I understood the current pointer stuff it
> constructs the top-level list by doing pointer stuff to remove all
> messages which are replies from the complete message list). Indeed, the
> diff is more complicated than the new code!
> 
> On Sun, 25 Nov 2012, Austin Clements <amdragon@MIT.EDU> wrote:
> > This series adds a library API for iterating over all messages in a
> > thread in sorted order.  This is easy for the library to provide and
> > difficult to obtain from the current API.  Plus, if you don't count
> > the code added to the bindings, this series is actually a net
> > decrease of 4 lines of code because of simplifications it enables.
> >
> > Do we want the API to do more?  Currently it's very minimal, but I can
> > imagine two ways it could be generalized.  It could take an argument
> > to indicate which message list to return, which could be all messages,
> > matched messages, top-level messages, or maybe even unmatched messages
> > (possibly all in terms of message flags).  It could also take an
> > argument indicating the desired sort order.  Currently, the caller can
> > use existing message flag APIs to distinguish matched and unmatched
> > messages and there's a separate function for the top-level messages.
> > However, if the API could do all of these things, it would subsume
> > various other API functions, such as notmuch_thread_get_*_date.
> 
> I don't know if this is the right API. For the matched message etc I
> think using the existing message flag APIs is simple enough. I am not
> sure about sort orders though: that looks like it would be much easier
> for the caller to have the correct sort by I am not sure what users
> would need it.

For sort order, I would be inclined to simply construct the reverse
list the first time a caller asks for it.  Theoretically the caller
could do this just as easily as the library, except that we don't
expose the list routines.

If I do add sort order, I would also want to add some control over
which list is returned, since it would be asymmetric to be able to
request all messages in either order, but top-level messages only in
oldest-first.  I think this would be pretty simple, and would give us
a reasonably general-purpose and extensible API.  (It would also solve
the naming conundrum I mentioned below in my original email.)

> Best wishes
> 
> Mark
> 
> 
> 
> 
> >
> > Also, is this the right name for the new API?  In particular, if we do
> > later want to add a function that returns, say, the list of matched
> > messages, we'll have a convention collision with
> > notmuch_thread_get_matched_messages, which returns only a count.