----- Original Message ----
From: Fabio Fracassi <f.fracassi@gmx.net> To: boost@lists.boost.org Sent: Sun, April 17, 2011 6:00:17 PM Subject: Re: [boost] [locale] Formal review of Boost.Locale library starts tomorrow
On 16/4/2011 15:29, Artyom wrote:
So I do not expect you to write such a thing, but if someone did I'd expect you to integrate it. By the way, can you "guesstimate" how much work it would take?
I have no idea, for example to handle XLIFF format it is required to have... an XML parser so I don't know what would it take.
I understand that it is hard, so let me ask another question, if the gettext loading support was missing, how much time would someone need to implement it. Ballpark figure is enough (a day, a week, a month?).
It took me quite a long time due to fact that I needed to implement C equation parsing (took a few days) and to learn this format. At the beginning I was using some MIT code but then I had rewritten everything from the scratch. So it took maybe about a week or so.
Your docs do not say what happens when I do this: locale::format("Today is {1}.") % date(d) I'd expect it to work and give the date in some sensible default formatting.
Can you answer the question above?
Actually, one of the conclusions from the review that it is better for boost::locale::Date_time to have default output as date time formatting not as a number so boost::locale::date_time dt = ..; boost::locale::format("Today is {1}") % dt would display both date and time. And if dt is boost::date_time::date object it would display date as it was written to stream. If you want to display only date or time you would have to put: boost::locale::format("Today is {1,date}") % dt As boost::locale does not have separate date and time class but date_time - which combines both concepts of calendar and POSIX time in single object. Also I strongly encourage users to put as much information to format as possible where std::cout << format(translate("Today is {1,date}")) % dt; Over std::cout << translate("Today is:") << as::date << dt; As translator can provide : "Today {1,ftime='%Y-%M-%d'}" or something like or even more complex according to his needs like "Today {1,date} ({1,locale=he_IL.UTF-8@calendar=hebrew,date})" And display "Today Jan 1, 1970, (5 in Nissan 5770)" So basically such information should be in formatting string.
I'd hate if we had to do something like this:
boost::format("Sensor Value (at %1%): %2$.2%") % (locale::format("{1,date_time}") % date) % value
You can just do boost::locale::format("Sensor Value (at {1,dt}): {2,p=2}")
Thats great, so it should be easy to integrate locale::format and boost::format, shouldn't it?
Integrate yes, but use same format no as it requires reimplementing boost::format functionality from the scratch as the approaches are too different.
Minimally I'd expect
boost::date_time dt = ...; locale::format("Today is {1,date}.") % dt to work.
There are several problems:
1. boost::date_time has its own formatter facets and they can't be overridden 2. The use of locale facets in Boost.DateTime is quite incorrect.
Ok I'd settle for this:
boost::date_time dt = ...; boost::locale::date_time ldt = dt; locale::format("Today is {1,date}.") % ldt
or locale::format("Today is {1,date}.") % locale::date_time(dt)
There is no boost::date_time there is only boost::date_time::date (without time at all) and boost::date_time::ptime which has unclear semantics whether it is UTC or local time (which is quite wrong) as ptime can be created from locale_time clock and universal_time clock (How POSIX time can be local time? It is same as PI=6.28 but this is different story...) So you need to convert it explicitly and the reasonable way is up to you.
It is not that simple.
I think it can be worked out together with cooperation of Boost.DateTime author/maintainer.
Yes, that was kind of the Idea.
Of course it can be resolved in future, but with current implementation of boost::Date_time it is not that simple.
Regards
Fabio
Artyom