RE: Fwd: Last Call: UTF-16, an encoding of ISO 10646 to Proposed

[Harald Tveit Alvestrand <Harald@Alvestrand.no>]

At 09:26 16.12.99 -0500, =?UNKNOWN?Q?Fran=E7ois?= Yergeau wrote:
> > De: Ira Mcdonald [mailto:imcdonal@sdsp.mc.xerox.com]
> > Date: mercredi 15 décembre 1999 23:32
> >
> > Over the wire, UTF-16 has a long list of drawbacks
> > and no visible advantages.  It shouldn't be 'legitimized'
> > by IETF Proposed Standard designation.
>
>I wouldn't really object to Informative instead of PS, but would like to
>hear more about that "long list of drawbacks".  My own list is rather short
>and parts of it are related to C string and ASCII-thinking and will
>disappear over time. I also have a (short) list of advantages.

My list of disadvantages:

- No compatibility with cstrings due to NULL
- Inability to represent characters outside Planes 0-16
- VERY bad expansion factor for characters outside Plane 0 (100% overhead)
- No ability to mix ASCII and UTF-16 elements in a simple viewer
- Two incompatible byte orders

My list of advantages:

- Does not require conversion between UCS-2 and UTF-16 when only Plane 0
   characters are used in the UTF-16

Note that the single advantage may be listed as a disadvantage if there 
turns out to be lots of applications that "support" UTF-16 the way they 
currently "support" Unicode - by throwing away the high-order bits....

                     Harald A

--
Harald Tveit Alvestrand, EDB Maxware, Norway
Harald.Alvestrand@edb.maxware.no