[PATCH 12 of 12] templater: add a method to list labels in a namespace

[Sean Farley]

Augie Fackler writes:

> On Mon, Aug 18, 2014 at 04:18:08PM -0500, Sean Farley wrote:
>> # HG changeset patch
>> # User Sean Farley <sean.michael.farley at gmail.com>
>> # Date 1408394323 18000
>> #      Mon Aug 18 15:38:43 2014 -0500
>> # Node ID fe9b72aa7e160e690813cfe4242b013fb147937e
>> # Parent  e1ab9da20be237323a1340efa16b58b03525596f
>> templater: add a method to list labels in a namespace
>
> I don't quite see the why of this series - is it so we can add other
> types of labels to a changeset without having to do a bunch of
> tapdancing? How would that be useful?
>
> (The generality is kind of nice, and I can sort of see a use for
> remotebranches in that a remotebranch could become a non-tag label,
> but I'm not sure I'm sold that it'd be worth doing there, because then
> you'd still have to wire in some lookup mechanics.)

Yep, you guessed it. This series sprouted from my work on remotebranches
(to add bookmark support). The "why" of this series is to turn off the
flood of local tags (hg-git, remotebranches, etc.)

The key features of adding this machinery to core:

- no more polluting the output of 'hg tags'
- automatic template keywords / functions (see patches 11-12)
- displaying correctly in the log (see patch 7)
- automatic tab completion (see patch 9)
- automatic support for color (see patch 7)

Now, all an extension would have to do is (actual test code I used):

    repo.label("foo", "f1", repo['8a6a86c9a5b5'].node())
    repo.label("foo", "f2", repo['8a6a86c9a5b5'].node())
    repo.label("bar", "b1", repo['8a6a86c9a5b5'].node())
    repo.label("bar", "b2", repo['8a6a86c9a5b5'].node())

And they would get all the nice coloring, tab completion, and templating
without having to add that themselves (though, you could certainly add
more fancy things).

For example, imagine that the bugzilla extension could add all ticket
numbers to known commits:

    repo.label("tickets", "issue1234", repo[foo].node())

And in the command line:

    $ hg up issue<tab>
issue1234 etc.

Anyway, those are just some ideas.