Re: [PATCH][BZ #15527] strftime_l.c: Support lowercase output

[Rafal Luzynski <digitalfreak at lingonborough dot com>]

Hi,

(Top-posting to conform to the style you already started. ;)

Your patch has drawn my attention. I must admit that I have not
analyzed it very thoroughly but OTOH I'm not the right person to
say the patch should be committed.

Only one question: what would be the order of applying
the flags? Should "%^#A" mean "convert to uppercase and then
swap" or "swap the case and then convert to uppercase" or
should it be an idiom to "convert to lowercase" no matter
what is the actual order? Should "%^#A" do the same as "%#^A"?

At first sight it may seem that usefulness of this feature
is limited: who would need a "convert to lowercase" switch
if all letters are already lowercase and those which are
uppercase (first letters of months names and weekdays names)
should always be uppercase?

But that's true only for English, German and maybe few other
languages. Not true for lots of others, including my and also
I guess your language. In many languages there is no rule
saying that month names and weekday names should always begin
with uppercase but other rules may apply: it should begin with
uppercase if it's a beginning of a sentence or a beginning of
a title. I really don't like months names (standalone) or weekday
names (a full date starting with a weekday name) starting with
lowercase just because in English they are always uppercase
and developers don't have to worry about it so they eventually
leave all other languages in all lowercase. I really wish there
was a strftime() flag converting words to titlecase. We have
"convert to uppercase" and "swap the case" but no "convert to
lowercase" nor "convert the first letter to uppercase". OTOH,
the implementation of this feature should not be left to the app
developers because not all languages need it, and converting
to the uppercase/titlecase is not a trivial task (in case of
UTF-8, how many bytes are occupied by the first letter? how
many bytes will its uppercase version occupy? does the letter
feature only lowercase and uppercase or is it a ligature
and has it a separate titlecase, like lj → Lj → LJ?) so better
should be implemented by a core library.

Unfortunately, I don't have a good candidate for a "convert
to lowercase" or a "convert to titlecase" switch. But your
patch solves the problem if we also provide all months names
and all weekday names in all locale data for all languages
in titlecase, even if a language does not require it by default.
Then we would have:

"%^A" - convert to uppercase => "SUNDAY";
"%#A" - swap the case => "sUNDAY" (yes, not useful);
"%^#A" - convert to lowercase => "sunday" (in the middle of
         a sentence, as required in many languages but not
         in English);
"%A" - leave unchanged, titlecase => "Sunday" (default, always
       in English and some other languages, required in the
       beginning of a sentence in many other languages).

We would have a way to convert all words to any (reasonable)
case and the decision would be always left for the translators
without any change in any application code. What do you guys think?

Regards,

Rafal


29.11.2016 13:41 Jakub Martisko <jamartis@redhat.com> wrote:
>
>
> Sorry, this was supposed to be a reply to:
> https://sourceware.org/ml/libc-alpha/2016-06/msg00575.html
>
> On 29.11.2016 13:21, Jakub Martisko wrote:
> > Hi, are there any updates regarding this functionality?
> >
> > On 15.6.2016 10:54, Jakub Martisko wrote:
> >> strftime_l.c doe not provide easy way to produce lowercase
> >> output. While the function to create lowercase is
> >> implemented, there is no flag which would cause it to be
> >> called. Provided patch checks, whether combination of
> >> to_uppcase and change_case flags is used and sets to_lowcase
> >> if both of them are set which leads to lower case output.
> >>