Re: anti formatter

From: rogeeff (rogeeff_at_[hidden])
Date: 2001-12-20 14:57:23

--- In boost_at_y..., Karl Nelson <kenelson_at_e...> wrote:
> > Why not like this:
> > 
> > BOOST_START_FORMAT_DEFINITION( classic_date_format, 3 
(int,int,int))
> >  arg1 << '-' << arg2 << '-' << arg3 
> > BOOST_END_FORMAT_DEFINITION
> > 
> > BOOST_START_FORMAT_DEFINITION( us_date_format, 3 (int,int,int))
> >  arg2 << '/' << arg1 << '/' << arg1
> > BOOST_END_FORMAT_DEFINITION
> > 
> > BOOST_START_FORMAT_DEFINITION( long_date_format, 3 (int,int,int))
> >  day_of_week( arg1, arg2, arg3 ) 
> >     << ' ' << arg2 << '/' << arg1 << '/' << arg1
> > BOOST_END_FORMAT_DEFINITION
> 
> So this solves date, but how about every other language problem
> which is likely to occur.  Many languages don't have the same 
> word ordering that as English.  You can't possibly make macros
> to cover all of them.  

You would need only 2 macro BOOST_START_FORMAT_DEFINITION, 
BOOST_END_FORMAT_DEFINITION. Everything else between brakets.

> 
> Look over http://www.iro.umontreal.ca/contrib/po/HTML/gettext.html
> to see what other languages do and thus why C++ should provide
> something similar.
> 
> printf (gettext ("String `%s' has %d characters\n"), s, strlen (s));
> 
> printf ("%2$d Zeichen lang ist die Zeichenkette `%1$s'", s, strlen 
(s));
> 
> 
> Considering the string is most likely provided by outside 
translation
> firm who knows nothing about your code how would your approach 
handle
> the above?
> 

As far as I undefstand in you example you propose:

1. Have a resource storage in a form:
FORMAT_ID    | FORMAT_TEXT
1            | blah blah blah
2            | blah blah blah
...          | blah blah blah
236          | String `%s' has %d characters\n
...

2. You will need 1 storage per language.
3. You will need library that will access that storage in runtime to 
get a message text by message id.
4. Usage will look like this:
     
printf( get_format( 236 ), s, strlen (s));

---------------------------------------------------------------

Now what an alternative:
1. Have a header file in a form

START(format1)   blah blah blah                       END
START(format2)   blah blah blah                       END
          ...      
START(format236) "String " << arg1 << " has " << strlen(arg1) << " 
characters\n "  END
         ...                                                 

2. You will need 1 version of a header per language.
3. You will need include this header where needed
4. Usage will look like this:

std::cout << format236( s );
 
> 
> Compile time translation means providing seperate binaries for
> i18n programs.  This to me is very bad. 
> 

Now if you wish to be able to change a language in runtime, you can 
provide a format_message<format_id>( args ) interface.

[...]
>  
> --Karl

Gennadiy.