[PATCH] formatter: allow json to handle more levels of depth

[Yuya Nishihara]

On Sun, 6 Mar 2016 23:06:49 +0000, Kostia Balytskyi wrote:
> On 3/6/16, 4:16 PM, "Yuya Nishihara" <youjah at gmail.com on behalf of yuya at tcha.org> wrote:
> >On Fri, 4 Mar 2016 16:29:26 +0000, Kostia Balytskyi wrote:
> >> This is a sample output of `evolve --list` with below fix applied to mercurial:
> >> 
> >> ```
> >> ikostia at dev1902.lla1:~/temprepos/supertroubledrepo$ HGRCPATH= ~/clowncopter/hg evolve --list  --config extensions.lz4revlog= --config extensions.color= --config extensions.evolve=~/evolve/hgext/evolve.py
> >> [
> >> ...
> >>   {
> >>     "desc": "e (e+f split)",
> >>     "divergentsets": [{"divergentwith": [{"node": "01a3e66ba0301a4cbb7d519f8b9980af271241bd"}],"gcea": "3efa43a7427b9b19dc715853251d4891d3e9334c"}, {"divergentwith": [{"node": "add9a356b8cfca95c588f51f05291ad97ffbaea8"}],"gcea": "3efa43a7427b9b19dc715853251d4891d3e9334c"}],
> >>     "node": "84e1c6ae319d139241a02ef5e939d7494b9b11d7",
> >>     "unstableparents": [{"unstableparent": "1995fc658ad6db877b932a45deb411980ccc064e"}]
> >>   },
> >
> >Looks like you've designed the data structure to be processed by the templater.
> >Isn't that verbose as a JSON output?
> >
> >For example, "unstableparents" could be a list of node ids in JSON:
> >
> >  "unstableparents": ["1995fc658ad6db877b932a45deb411980ccc064e"]
> >
> >but templater requires a key:
> >
> >  "unstableparents": [{"unstableparent": "1995fc658ad6db877b932a45deb411980ccc064e"}]
> >
> >moreover it would need a ctx object for full templating:
> >
> >  {unstableparents % "{rev}:{node|short} {desc|firstline}"}
> >   ~~~~~~~~~~~~~~~
> >     yields {'ctx': ctx}
> >
> >I don't have any idea right now, but nested data structure wouldn't be handled
> >well by the current formatter API.
> 
> I guess it depends on whether you want to be able to have all the 'rev', 'node', 'desc' and stuff to be there. If you're fine with having a limited output where you only have access not to all the ``ctx`` fields, but just some predefined set of them, my approach should be good enough.

Hmm, but we provide -T option because people are likely to have their own needs.
They'll expect {rev}, {branch}, etc. can be used if "evolve -l" looks like a
log command.

That said, I think it's okay to start from a limited version. My main concern
is that a nested data structure looks ugly in JSON if it has to be compatible
with the templater. And JSON output should be stable. (timeless is working on
it.)