Re: [PATCH v7 14/17] ref-filter: allow porcelain to translate messages in the output

[Matthieu Moy <Matthieu.Moy@grenoble-inp.fr>]

Karthik Nayak <karthik.188@gmail.com> writes:

> cc'in Matthieu since he wrote the patch.
>
> On Sat, Nov 19, 2016 at 4:16 AM, Jakub Narębski <jnareb@gmail.com> wrote:
>> W dniu 08.11.2016 o 21:12, Karthik Nayak pisze:
>>> From: Karthik Nayak <karthik.188@gmail.com>
>>>
>>> Introduce setup_ref_filter_porcelain_msg() so that the messages used in
>>> the atom %(upstream:track) can be translated if needed. This is needed
>>> as we port branch.c to use ref-filter's printing API's.
>>>
>>> Written-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
>>> Mentored-by: Christian Couder <christian.couder@gmail.com>
>>> Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
>>> Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
>>> ---
>>>  ref-filter.c | 28 ++++++++++++++++++++++++----
>>>  ref-filter.h |  2 ++
>>>  2 files changed, 26 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/ref-filter.c b/ref-filter.c
>>> index b47b900..944671a 100644
>>> --- a/ref-filter.c
>>> +++ b/ref-filter.c
>>> @@ -15,6 +15,26 @@
>>>  #include "version.h"
>>>  #include "wt-status.h"
>>>
>>> +static struct ref_msg {
>>> +     const char *gone;
>>> +     const char *ahead;
>>> +     const char *behind;
>>> +     const char *ahead_behind;
>>> +} msgs = {
>>> +     "gone",
>>> +     "ahead %d",
>>> +     "behind %d",
>>> +     "ahead %d, behind %d"
>>> +};
>>> +
>>> +void setup_ref_filter_porcelain_msg(void)
>>> +{
>>> +     msgs.gone = _("gone");
>>> +     msgs.ahead = _("ahead %d");
>>> +     msgs.behind = _("behind %d");
>>> +     msgs.ahead_behind = _("ahead %d, behind %d");
>>> +}
>>
>> Do I understand it correctly that this mechanism is here to avoid
>> repeated calls into gettext, as those messages would get repeated
>> over and over; otherwise one would use foo = N_("...") and _(foo),
>> isn't it?

That's not the primary goal. The primary goal is to keep untranslated,
and immutable messages in plumbing commands. We may decide one day that
_("gone") is not the best message for the end user and replace it with,
say, _("vanished"), but the "gone" has to remain the same forever and
regardless of the user's config for scripts using it.

We could have written

  in_porcelain ? _("gone") : "gone"

here and there in the code, but having a single place where we set all
the messages seems simpler. Call setup_ref_filter_porcelain_msg() and
get the porcelain messages, don't call it and keep the plumbing
messages.

Note that it's not the first place in the code where we do this, see
setup_unpack_trees_porcelain in unpack-trees.c for another instance.

Karthik: the commit message could be improved, for example:

Introduce setup_ref_filter_porcelain_msg() so that the messages used in
the atom %(upstream:track) can be translated if needed. By default, keep
the messages untranslated, which is the right behavior for plumbing
commands. This is needed as we port branch.c to use ref-filter's
printing API's.

Why not a comment right below "} msgs = {" saying e.g.:

	/* Untranslated plumbing messages: */

>> I wonder if there is some way to avoid duplication here, but I don't
>> see anything easy and safe (e.g. against running setup_*() twice).

I think we do need duplication for the reason above.

-- 
Matthieu Moy
http://www-verimag.imag.fr/~moy/