Re: [PATCH ps/stash-in-c] strbuf_vinsertf: provide the correct buffer size to vsnprintf

From: Johannes Sixt <j6t@kdbg.org>
Date: Feb 5, 2019, 20:30 UTC
Message-ID: <ef5f66fb-7467-93be-00fd-7900ce961f72@kdbg.org>
In-Reply-To: <nycvar.QRO.7.76.6.1902051140060.41@tvgsbejvaqbjf.bet>

Am 05.02.19 um 12:06 schrieb Johannes Schindelin:

> The real examples are much more mundane, and very different from what you
> suspected, e.g. inserting the tag header before the tag message in
> `create_tag()` in `builtin/tag.c`. Basically, it is building up a strbuf
> for the sake of calling `strbuf_insert()` to insert that string elsewhere.

I had a look, and this example does not convince me at all. If separation of concerns were applied well around the launch_editor APIs, you would not need strbuf_insert() in the first place. But, alas, these functions focus more on DRY, and that is often the opposite of separation of concerns.

> In any case, the mere existence, and use, of `strbuf_insert()` is a pretty
> clear counter case to the idea that `strbuf_vinsertf()` would encourage
> invalid code flows.

Nobody wants to get rid of strbuf_insert(). I have worked with at least 3 string APIs. All have insert operations, and some have string formatting capabilities, but none of them conflate the two operations into one. Maybe, there is a plan behind it? strbuf is the first (my 4th) API that does, and it was non-trivial to get it right...

-- Hannes