Re: [boost] [Boost.Locale] New Release

Subject: Re: [boost] [Boost.Locale] New Release
From: Artyom (artyomtnk_at_[hidden])
Date: 2010-03-13 04:44:58

Hello Eric,

> > 
> > That's a very interesting wrapper of ICU.
> > It might even kill off my Unicode library.
> 
> I think Boost probably needs a Unicode library that is
> *not* a wrapper of ICU.

One of the points I considered when I was developing Boost.Locale was
actually independence of ICU. You would not find any interface that
exposes ICU, (even thou it is quite connected to it).

In fact, for CppCMS I have its small version for embedded systems
(that lacks 80% of its original abilities that work over std::locale only
and it is quite useless for Boost).

So it is possible to replace someday in future ICU or parts of it with
other (maybe better) Unicode engine.

For example, I do not use ICU Resource Bundles for message translation,
I actually use GNU Gettext MO Catalogs (not runtime library). 

**However** developing and debugging new library that nearly close to
abilities of ICU (v4.2 has about 680,000 lines of source code) requires
many hundred man years and is absolutely unfeasible, unless some big
company would donate their time build it (as IBM does with ICU).

Please read this: http://cppcms.sourceforge.net/boost_locale/html/tutorial.html#design-rationale

So the question isn't whether Boost needs its own Unicode library,
or it needs good ICU wrapper the question is whether Boost needs
Unicode library at all.

For the record: I remember somebody posted initial version of Unicode
library that included **only** properties of characters and it
didn't went much far then that. But you also need CLDR and its processing,
you need dictionaries for proper break iteration and so on,
implement numerous Unicode algorithms and so on. This is huge work to do.

Once I did comparison of ICU with glib and Qt (big fat libraries that
have lots of goodies for Unicode, neither one of them was as correct
as ICU).

> What is it's license? 

You mean Boost.Locale? Boost license. If you ask about ICU license,
it is permissive license very similar in terms to Boost, MIT and other
such licenses: 
http://source.icu-project.org/repos/icu/icu/trunk/license.html

> How generic is
> it? (E.g. can I run Unicode algorithms over non-contiguous
> data?)

Only boundary iterator provides API that allows you to work
over non-continuous data but internally it is still converted to
continuous.

But neither ICU. It has very few classes (BreakIterator and few others) 
that allow you to work over non-continuous data (UText) and this is very
painful in any case (UText is not very nice API).

So, during design I aimed to rather correct and useful approach then
totally generic and extremely efficient one.

Best,
  Artyom