Re: On shipping more of our technical docs as manpages

From: Jonathan Nieder <jrnieder@gmail.com>
To: Jeff King <peff@peff.net>
Cc: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
	"Junio C Hamano" <gitster@pobox.com>,
	"Stefan Beller" <sbeller@google.com>, git <git@vger.kernel.org>
Subject: Re: On shipping more of our technical docs as manpages
Date: Wed, 26 Sep 2018 23:34:04 -0700	[thread overview]
Message-ID: <20180927063404.GB220288@aiede.svl.corp.google.com> (raw)
In-Reply-To: <20180927062011.GA1318@sigill.intra.peff.net>

Hi,

Jeff King wrote:
> On Wed, Sep 26, 2018 at 10:44:33PM +0200, Ævar Arnfjörð Bjarmason wrote:

>> In terms of getting an overview it's indistinguishable from
>> comments. I.e. there's nothing like an index of:
>>
>>     man git-api-strbuf     ==> working with strings
>>     man git-api-sha1-array ==> list, iterate and binary lookup SHA1s
>
> I agree that is a problem, especially for contributors less familiar
> with the code base. But I think generating an index is a separate (and
> much easier) problem than formatting all of the documentation.
>
> We already have the /** convention I mentioned above. Could we have
> another micro-format like:
>
>   /** API:strbuf - working with strings */
>
> in each header file? That would make generating such an index pretty
> trivial.

Can you spell out the problem for me a little more?  E.g. if we had a
convention that the first comment in strbuf.h should say

	/* strbuf - Git's standard string type */

or even just

	/* Git's standard string type */

would that do the trick?

>> I'm also not in the habit of opening the *.h file for something, I
>> usually just start reading the *.c and only later discover there's some
>> API docs in the relevant *.h (or not).
>
> Interesting. I'm not totally opposed to putting the documentation
> alongside the actual code. It does feel a bit cluttered to me, but I
> think you're right that it keeps everything as close together as
> possible.

I've experienced projects following both conventions.  One thing I like
a lot about documentation in the header file is that it encourages
people to make the API documentation self-contained.  That is, you
describe the contract in a way that doesn't require reading the
implementation for details.

It took me a while to get used to this kind of convention but now I
really like it.  So I really do prefer to keep putting API
documentation in the header files in Git.  (Implementation
documentation in the source files is of course also very welcome.)

>> It means you can't avoid seeing it or updating it when source
>> spelunking, and it leaves header files short, which is useful when you'd
>> like to get a general API overview without all the docs. Our documented
>> headers are quite fat, e.g. strbuf.h is 60% of the size of strbuf.c, but
>> less than 20% when you strip the docs.
>
> I don't use folds in my editor, and I guess nobody else in this thread
> does, either. But they may be a reasonable tool for "wow, there are
> comments, declarations, and definitions all together and I just want to
> view one of them". In vim, try "set foldmethod=syntax" and then "zc" to
> close the folds.

I use kythe to get an outline view of the header files.

[...]
>> E.g. on Debian you can "apt install git-doc" and browse stuff like
>> file:///usr/share/doc/git-doc/technical/api-argv-array.html which is the
>> HTML formatted version, same for all the other api-*.txt docs.
>
> IMHO this is just silly. What am I as an end user going to do with
> api-argv-array.html?

In Debian we just ship all the docs.  For something like
technical/pack-heuristics, it's quite nice.  For the API docs, I think
they belong in the headers.

Thanks,
Jonathan