[h5md-user] String encoding

[Peter Colberg]

Hi all,

I wish we would have a test suite for H5MD.

Recently we decided to use fixed-length string datatypes for the
attributes defined in H5MD. Unfortunately, with h5py, this forces a
string to be encoded in ASCII; reading a fixed-length string encoded
in UTF-8 will raise an error.

http://docs.h5py.org/en/latest/strings.html#how-to-store-text-strings

Since it is crucial for Fortran programs to *conveniently* write H5MD
metadata such as the author’s name, but less crucial to *conveniently*
read said metadata, I suggest we follow Felix’ earlier proposal, with
the following refinement:

The attributes in h5md/ may be stored using either a fixed-length
ASCII string datatype, or a variable-length UTF-8 string datatype.

Regards,
Peter