Re: [boost] [locale] Review. Internationalization library?

Subject: Re: [boost] [locale] Review. Internationalization library?
From: Artyom (artyomtnk_at_[hidden])
Date: 2011-04-16 09:00:36

> 
> I have made a diagonal reading and I  find your library really interesting. I 
>think I will spent quite more time  reviewing it.
> 
> I have just a first minimal and formal remark. When I see  the overloading of 
>the translate function
> 
> message  boost::locale::translate (char const *msg)
> message boost::locale::translate  (char const *context, char const *msg)
> message boost::locale::translate (char  const *single, char const *plural, int 
>n)
> message boost::locale::translate  (char const *context, char const *single, 
>char const *plural, int n)
> message  boost::locale::translate (std::string const &msg)
> message  boost::locale::translate (std::string const &context, std::string 
>const  &msg)
> message boost::locale::translate (std::string const &context,  std::string 
>const &single, std::string const &plural, int n)
> message  boost::locale::translate (std::string const &single, std::string const  
>&plural, int n)
> 
> this let me think that it would be difficult to know  know what is the 
message,
> the context, the domain, whether the message is the  singular or plural form.
> 

This is the general concept of how gettext used around. So I stick with its 
conversion
extending it, same concept used in Qt. It is quite common.

I agree that it is not perfect but it seems to be ok.

> The equivalent for (w)gettext uses the c-like  idiom, i.e. uses different 
>names.
> 
> std::string boost::locale::gettext  (char const *id, std::locale const 
>&loc=std::locale())
> std::string  boost::locale::ngettext (char const *s, char const *p, int n, 
>std::locale const  &loc=std::locale())
> std::string boost::locale::dgettext (char const  *domain, char const *id, 
>std::locale const  &loc=std::locale())
> std::string boost::locale::dngettext (char const  *domain, char const *s, char 
>const *p, int n, std::locale const  &loc=std::locale())
> std::string boost::locale::pgettext (char const  *context, char const *id, 
>std::locale const  &loc=std::locale())
> std::string boost::locale::npgettext (char const  *context, char const *s, char 
>const *p, int n, std::locale const  &loc=std::locale())
> std::string boost::locale::dpgettext (char const  *domain, char const *context, 
>char const *id, std::locale const  &loc=std::locale())
> std::string boost::locale::dnpgettext (char const  *domain, char const 
>*context, char const *s, char const *p, int n, std::locale  const 
>&loc=std::locale())
> 
> Neither is satisfying me. 

These are mostly gettext compatibility functions so users familiar
with gettext would find themselves with (almost) same API.

> I was wondering  if the use of Boost.Parameters could help. 
> 

I'm not really familiar with Boost.Parameters but from quick glance it requires
not-so trivial template metaprogramming but what is even more important
I'm afraid that things like

   translate(context_ = "File","Open")

May scary off some average C++ programmers that would not understand what
is this thing 

   context_ = "File"

Finally I want Boost.Locale be used by not brilliant C++ programmers as well.

I know what hard times I have explaining about boost::bind to average
C++ programmers so making things like that would not help too much.

> An alternative could also be  to define some thin wrappers that state clearly 
>what is the meaning of the  string or const char * parameters, for example we 
>could have
> 
> struct  domain {
> domain(const char*);
> domain(std::string const&);
> operator  const char*() const; 
> operator std::string() const; 
> };
> 
> The same  for context, plural.
> Note that we don't need to wrap the message itself as this  parameter is 
>mandatory.
> 
> The examples
> 
> cout <<  format(translate("You have 1 file in the directory",
> "You have {1} files in  the directory",files)) % files <<  endl;
> 
> button->setLabel(translate("File","open"));
> 
> 
> could be  written as
> 
> cout << format(translate("You have 1 file in the  directory",
> plural("You have {1} files in the directory"),files)) % files  <<  endl;
> 
> button->setLabel(translate(context("File"),"open"));
> 
> With  this modification, the (w)gettext could all share the same names and 
>there
> will  be no need to use c-like names.
> 
> What you  think?

This one more interesting. However there an important point to check:

Integration with xgettext - would it be able to read this or entire new 
xgettext should be developed to extract strings.

I need to think about, probably it may be an alternative.

> 
> Best,
> Vicente

Thanks,

  Artyom