Hi Peff,

On Wed, 19 Jun 2019, Jeff King wrote:

> On Wed, Jun 19, 2019 at 04:58:50PM +0700, Nguyễn Thái Ngọc Duy wrote:
>
> > This is probably just my itch. Every time I have to do something with
> > the index, I need to add a little bit code here, a little bit there to
> > get a better "view" of the index.
> >
> > This solves it for me. It allows me to see pretty much everything in the
> > index (except really low detail stuff like pathname compression). It's
> > readable by human, but also easy to parse if you need to do statistics
> > and stuff. You could even do a "diff" between two indexes.
> >
> > I'm not really sure if anybody else finds this useful. Because if not,
> > I guess there's not much point trying to merge it to git.git just for a
> > single user. Maintaining off tree is still a pain for me, but I think
> > I can manage it.
>
> I don't have any particular use for this, but I am all in favor of tools
> that make it easier to access and analyze information kept in our
> on-disk formats (some of this is available via --debug, I think, but
> AFAIK most of the extension bits are not).
>
> And I'd rather see something like JSON than inventing yet another ad-hoc
> output format.
>
> I think your warning in the manpage that this is for debugging is fine,
> as it does not put us on the hook for maintaining the feature nor its
> format forever. We might want to call it "--debug=json" or something,
> though, in case we do want real stable json support later (though of
> course we would be free to steal the option then, since we're making no
> promises).

Traditionally, we have not catered well to 3rd-party applications in Git,
and this JSON format would provide a way out of that problem.

So I would like *not* to lock the door on letting this feature stabilize
organically.

I'd be much more in favor of `--json[=<version>]`, with an initial version
of 0 to indicate that it really is unstable for now.

Ciao,
Dscho