Re: printf issue with thousands separator

[Dr . Jürgen Sauermann]

    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
>
>
>
>
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