Re: Will Lua kernel use Unicode in the future?

[Klaus Ripke <paul-lua@...>]

On Fri, Dec 30, 2005 at 10:22:16AM -0500, Dave Dodge wrote:
> On Fri, Dec 30, 2005 at 11:36:13AM -0200, Roberto Ierusalimschy wrote:
> > > I think the more important addition would be an easy Lua way to set the 
> > > locale to use the UTF8 encoding.
> > 
> > os.setlocale("UTF-8") ?
> 
> Locale names other that "C" and "" are implementation-defined.  For
> example on Solaris 8 I believe the recommended locale name for this
> would be "en_US.UTF-8".
for sorting you would probably want to use something like
os.setlocale("UTF-8", "ctype")
os.setlocale("de_PHONEBOOK", "collate")

while in theory the collations are well defined
by unicode.org, in practice you face two problems:
a) the definitions are updated every now and then
b) the correctness and completeness of implementations varies
In other words it's about as portable as XML.

So for persistent data like a database index which relies upon
being sorted, using libc's strcoll means looking for trouble.
You should better link against a given version of ICU,
which is fairly complete and portable,
and make sure to ship that exact version with your app.


cheers