[Haskell-cafe] Porting setlocale to Windows

[Alexey Shmalko]

According to man 3 setlocale:
> The setlocale() function returns NULL and
> fails to change the locale if the given combi-
> nation of category and locale makes no sense.

So, returning Nothing seems just fine for me.

I believe categoryToCInt can return any CInt, because it's result is
implementation detail. I mean, applications can't make any assumption
based on result of categoryToCInt. That's why changing it (while
keeping its type) shouldn't break anything.

Regards,
Alexey

2015-01-02 0:57 GMT+02:00 Sven Bartscher <sven.bartscher at weltraumschlangen.de>:
> I assume that "do nothing", means that a call to
> `setLocale LC_MESSAGES x` always returns Nothing (which may confuse
> some applications, but maybe it does in the right way).
>
> Then there's the question left, what categoryToCInt does. I could
> change it's signature to `Category -> Maybe CInt`, but that would mean
> breaking the API. Instead I could make say
> `categoryToCInt LC_MESSAGES = -1`, which may confuse some applications
> which assume that categoryToCInt returns valid integers. But I guess,
> that's not that much of a problem, since categoryToCInt is not really
> often used in packages other than setlocale itself.
>
> Regards
> Sven
>
> On Fri, 2 Jan 2015 00:13:58 +0200
> Alexey Shmalko <rasen.dubi at gmail.com> wrote:
>
>> Hi,
>>
>> The third option is to make `setLocale LC_MESSAGES` do nothing. I believe,
>> it's perfectly acceptable in this case and is much better than making it an
>> error.
>>
>> Regards,
>> Alexey
>>
>> 2015-01-01 21:45 GMT+02:00 Sven Bartscher <
>> sven.bartscher at weltraumschlangen.de>:
>>
>> > Greetings,
>> >
>> > A while ago I took over the packages setlocale.
>> > I now would like to make it portable to windows, but came across the
>> > problem that LC_MESSAGES isn't defined on mingw.
>> > I thought about these options, for solving this:
>> >  - Not defining LC_MESSAGES, which would mean, every package using
>> >    LC_MESSAGES wouldn't be portable to windows.
>> >  - Defining LC_MESSAGES as some an error, which would basically have
>> >    the same problem as above.
>> >
>> > I don't like either of these solutions, but don't know any better.
>> > I would be happy about suggestions.
>> >
>> > Regards
>> > Sven
>> >
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>> >
>> >
>
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