Re: printf issue with thousands separator

[Christian Robert]

Jürgen,

#include <stdio.h>
#include <locale.h>

int
main(int argc, char *argv[])
{
   setlocale (LC_NUMERIC, "en_US.utf8");

   printf("%'f\n", 555555.66);
}

print:

555,555.660000


my 2 cents...

Xtian.


On 2022-07-05 12:40, Dr. Jürgen Sauermann wrote:
> Hi Martin,
>
> I believe I understood your problem now. As far as *⎕FIO* is concerned it 
> should be fixed
> in *SVN 1579*:
>
> *      "%'.2f" ⎕FIO.sprintf 1234567.89**
> **1,234,567.89**
> *
>
> There could be a misunderstanding as to how 'Format by example' works (and that 
> misunderstanding
> might also be caused by my testcases). What the APL2 calls a left or right 
> "decorator" is not intended
> as an arbitrary string in the printf() fashion, but something that is directly 
> attached (and possibly
> suppressed) to a number. In most cases the left decorator is either the minus 
> sign or the overbar and
> the right decorator is not used. The rare exceptions where the right decorator 
> is used are:
>
> 1. negative numbers printed in parentheses instead of a minus sign. Sometimes 
> used in bookkeeping.
> 2. output of negative numbers in a different color (typically red) using VT100 
> escape sequences as
> left and right decorators.
>
> In the examples that you apparently tried there were 2 left decorators (one 
> being the $
> and the other being the minus sign) and Format by example simply does not allow 
> that.
>
> The problem with ⎕FIO was actually caused by glibc which apparently ignores  
> the ' flag even
> if the locale tells otherwise, On my machine (and in plain C):
>
> *int
> main(int argc, char *argv[])
> {
>     printf("%'f\n", 555555.66);
> }
> *
> prints:
>
> *555555.660000*
>
> I did already pass the ' flag to *sprintf() *in glibc but glibc then simply 
> ignored it.
>
> Best Regards,
> Jürgen
>
>
>
> On 7/5/22 10:08 AM, Martin Michel wrote:
> > Hi Jürgen,
> >
> > thanks for your quick reply.
> >
> > > I will look into adding support for the thousands separator (but not supporting 
> > > the
> > > locales nonsense). That is, the thousands separator will always be comma and not
> > > e.g. full-stop like in some countries and comma in others.
> > That would be great and I fully agree, locales support would be too much
> > of a requirement.
> >
> > > BTW format by example should have done the job (see the APL2 language
> > > reference page 140):
> > >
> > >
> > >        "5,555.50" ⍕ 1234.56
> > > 1,234.56
> > Well, I tried this but it only works for the simpler cases. I could
> > manage to format figures with the currency symbol on the right side but
> > the format by examples falls short if I want it on the left, combined
> > with negative numbers and also rounding (e.g. no decimal point in
> > example spec).
> >
> > So this works:
> >
> >        ' -1,555,555.40 $' ⍕ 123456.789 ¯987654.12
> >       123,456.79 $   -987,654.12 $
> >
> > But I have not found anything which would give me these results:
> >
> >      $ +123,457   $ -987,654
> >
> > As far as I have understood IBM APL2 Language Reference this is not
> > possible with format by example. I would be happy if you can convince me
> > otherwise, then I would indeed not need ⎕FIO.
> >
> > Kind regards,
> > Martin