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

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

Date: Mon, 26 Nov 2012 19:19:30 +0200

To: Austin Clements, Mark Walters

Cc: notmuch@notmuchmail.org

From: Tomi Ollila


On Sun, Nov 25 2012, Austin Clements <amdragon@MIT.EDU> wrote:

> 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.)

The code looks good to me. 

I'm interested to see the extensible interface for returning desired
list in desired sort order :)

Tomi

>
>> 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.

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