[RFC][PATCH v1] emacs: Replace `notmuch-search-result-format' evaluation.

[David Edmondson]

On Tue, Nov 25 2014, David Bremner wrote:
>> +A symbol corresponding to an attribute of the
>> + thread (e.g. `:date_relative' or `:subject').
>
> It'd be nice for the user to have a pointer here to figure out what
> the possible attributes are.

I don't believe that we currently document these anywhere. I'll add a
list in the form "this will include such attributes as ...".

Something that I didn't mention is that this implementation behaves
differently from the current one in two ways:

- The invisible authors are not available to isearch. That is, the
  current implementation hides the authors that couldn't be shown in the
  available space using invisible text that can be exposed during an
  isearch in the buffer. This isn't done with the new implementation.

- The truncation of author names is hard - they are just chopped at the
  defined width (minus space for the ellipsis). The current code tries
  to find a nice break point (between authors). That was done to better
  support the the above feature (as isearch won't match text across a
  visible/invisible boundary).

The first of these is complex to fix. The current implementation relies
on overlays, which in turn require direct access to the buffer where the
text will be rendered. The buffer isn't available to the formatting
function in the new implementation.

The second could be fixed relatively straightforwardly, but without a
fix for the invisible text, I'm not clear that it's useful (and in fact
may be harmful).