Re: when will HDF5 support Unicode?

> We've had several discussions of UTF-8 support.  The current ideas are
> incorporated in a RFC at:
> 
>    http://hdf.ncsa.uiuc.edu/RFC/Unicode/Unicode.html
> 
> Close reading of this RFC will indicate that we know how to support
> UTF-8 for user data, but support for UTF-8 for names is still TBD.

I would consider supporting only UTF-8 for names but permit users to
specify other encodings as well for user data, for two reasons:

 - fixed-width encodings (like UCS2) permit quick access to the nth
   character in a string

 - other encodings may permit more compact representation than UTF-8
   for strings that contain a lot of non-ASCII characters

Joel Spolsky's column is a good introduction to some Unicode issues,
but I recommend this article for developers:

  http://www.w3.org/TR/charmod/

For example, the above gives examples of some of the complications in
sorting datasets alphabetically in a Group if you support Unicode
names.  You might need to use the "Unicode Collation Algorithm" in
that case.  Fortunately, there are open source implementations for such
things in ICU (International Components For Unicode):

  http://icu.sourceforge.net/

--Russ