That is the theory, but in practice you will find multiple symbols all
looking suspiciously like an A.

   Well, I took a look at http://www.unicode.org/charts/PDF/U1D100.pdf 
("Western Musical Symbols"), and they don't seem to have a notation for
indicating that the drummer should ease off the hihat pedal for the next few
notes, and then dampen the sound by applying pressure again. The notation
looks something like:

<asciiArt>
|-- O ---->                   -- (o) -|
|                                     |
</asciiArt>

   And is drawn above the staff of five lines where the notes are usually
drawn. There are others missing as well (e.g. repeat the following section,
but apply this ending the first time, and that ending the second time;
repeat the previous four measures; the following 3 notes should be played in
the time of 2 notes; apply the wah-wah pedal when playing guitars; let the
strings of the guitar ring openly; etc.) I haven't suggested this to the
consortium because:

   (1) I didn't realize you could (but I've seen discovered
http://www.unicode.org/pending/proposals.html)
   (2) I don't know the terminology or official names for these musical
symbols, being only an amateur musician. I figure there must be someone else
out there more qualified to make these submissions than me, but perhaps the
intersection of the set of all musicians and the set of all people who care
about Unicode is rather small.

   Well, they have some symbols which are, AFAIK, internationally
recognized. In http://www.unicode.org/charts/PDF/U2600.pdf there's the
recycling symbol, the biohazard symbol, and the poison symbol. Perhaps you
could have internationally recognized road signs as well (yield, stop, left
lane merge, etc.)

   - Oliver

   Kent Paul Dolan brought up similar arguments.

   As I was replying to a post by Bent C Dalager, it occured to me that
Unicode does not concern itself with the representation of characters at
all, so it is perfectly feasible that Unicode could support "animated"
glyphs. My post is at
http://groups.google.ca/group/comp.lang.java.programmer/msg/cd269f6cfc8392fc

   There are actually quite a few "unprintable" characters in Unicode, so
it wouldn't be a novelty to have characters that could not actually be
displayed in a traditional text editor. In fact, the codecharts have an
entire section called "Invisible Operators"
(http://www.unicode.org/charts/PDF/U2000.pdf, though in actuallity, some of
the characters defined there are indeed "visible").

   \u2029, for example, "Paragraph Seperator" is invisible, and is merely
to control the flow of text. It cannot, in itself, be displayed in any form.

   So it doesn't seem unreasonable to have some unicode character "\ufoo"
which represents a ASL gesture, which cannot be represented via some static
glyph.

   - Oliver

I read somewhere they decide not to add any more ligatures.  However,
in typesetting you still need a code for them, so I suspect eventually
they will be given Unicode slots.

The original question was what might people do to  Unicode to expand
it, not what SHOULD they do.

There was a phonetic alphabet designed for native Canadian languages.
It is very pretty, but it is as almost as bad as Hebrew for having
very similar letters you would have to look carefully at to
discriminate.

It is probably an emergent property of the system.

You would get into trouble if it turns out that the exact stickiness
(however stickiness is measured) of the strands involved in the symbol
are vital to the correct interpretation of the message.

How do you represent stickiness in Unicode?

Or perhaps pheromones add vital information to the picture.

Our ability to do so presumably depends upon the aliens having the
exact same concept as we do as to what a glyph is. The simplest
variation (depending on 3D glyphs perhaps, or animated ones)* is
likely to throw off Unicode.

* - For all I know, Unicode may support this, but you get the idea.

Cheers
    Bent D

At one level I agree with you; there's something unnatural about conflating
characters and integers.  In fact Smalltalk works exactly how you suggest, and
my own Unicode implementation for Smalltalk (under construction) works that way
too, so I have a fair bit of experience using a system which separates the two
concepts.

But that's only half the story.  You also need to be able to do a significant
subset of arithmentical operations on character values (indexing into arrays
for instance), and such operations often turn up in places where constantly
casting back-and-forth between integer code points and actual characters would
be painful and/or inefficient.  Java doesn't really support the idea of
"hybrid" values -- half arithmetical, half not -- so, barring major changes to
the language, I'd stick with the current scheme, but make "char" wider.

It's perhaps worth emphasising that, in Unicode, a character has very little
meaning by itself -- it is, in general, not possible to do anything very useful
with a character which isn't an element of a stream or string.  Pretty-much the
only things you can legitimately do with a char are compare it with another
char or use it as a lookup index into Unicode character property tables.   A
character is /not/ like a short string -- it's a different class of entity
entirely.

Tell you what.  How about, since we're redefining Java anyway, we rename "char"
to "codepoint" ?  It would be more accurate...

Not that I know of, although it wouldn't surprise me to find the human-centric
design principles discussed somewhere.  Unicode includes rather a lot of
thoughtful and interesting meta-discussion in it's documentation (if not in the
standard itself).

The way that Unicode works is extremely practical and /not/ universal (see
below).  It introduces features only if they are used in some target
orthography.  Thus it has ligatures, since they are essential in many systems
of writing.  It also attempts to make round-tripping from other charsets, into
Unicode, and back possible (no information lost), and so has a very limited
number of Latin ligatures (and that's the /only/ reason it has Latin
ligatures).  No writing system uses colour to denote meaning (that I know of)
and so Unicode doesn't touch colour.  The result of this YAGNI-like focus on
features that are actually needed, is that Unicode inevitably reflects the
human processes which create written languages, and which determine their
logical structure.  One huge example is that human vision uses edge-detection
heavily.  As a result Unicode glyphs are /shapes/ -- shapes which can be
rendered as black-on-white.

BTW, don't get mislead by the odd few Unicode code points which are assigned to
non-visual purposes -- the BOM being a good example, or the directionality
markers.  There are damned few of those, and for the most part they only exist
in order to allow round-tripping or the use of Unicode in a context where
insufficient meta-information is available, and their use is disouraged in
other contexts.  Unicode is /about/ shapes.

It's worth considering how much Unicode /doesn't/ have which it might be
expected to include if the focus weren't so limited.  For instance it has no
way of expressing /semantic/ qualifiers on text such as italics (or, more
abstractly, emphasis).  It has no means of rendering prosody beyond the limited
expression implied by existing punctuation schemes[*].  Yet if the
text-to-speech example could be taken as a core use for Unicode -- i.e. as a
true alternative rendering of Unicode, on an equal footing with printing text
on paper -- then such annotations would seem to be highly desirable, perhaps
even necessary.

([*] Another aside: apparently English punctuation started out -- with the
Greeks, naturally -- purely as a way of expressing prosody, but at around the
time fully modern English emerged, the punctuation system had its own
mini-revolution: new marks were invented, old marks were reinterpreted or
discarded, and the role of punctuation shifted away from expressing prosody to
expressing grammar and other semantic features of text.)

I don't think it's a policy thing at all.  If this situation were ever to
arise, then I think one of two things would happen.  Either we humans (not
being able to "see" the patterns properly since we lack the necessary brain
circuitry) would develop an independent glyph-system for representing the
patterns (and whatever other features were needed). In that case the new glyph
system might get added to Unicode if enough humans wanted to represent
Spiderese texts in their discussions with other humans.  Note that the spiders
themselves would probably not be able to "see" our human glyphs any more than
we could see theirs, so this system would be solely for human use.  This is
roughly what has happened for musical notation[**]  Alternatively it might turn
out that human/spider brains were similar enough that we could read their
patterns directly (I have to say that I find this almost impossible to
imagine), in that case it would come down to the practicalities.  Does written
Spiderese break down into a glyph system similar enough to the existing human
ones for it to be expressed in the Unicode framework ?  I find this even harder
to imagine, but if it /did/ turn out that way then I see no reason for
spider-glyphs not to be added to Unicode.  To me (presupposing the existence of
other intelligences at all) it seems much more likely that their communications
wouldn't have a modality which was anywhere near close enough to human writing
to fit into Unicode.  Spiders, for instance, might be much more likely to use
moving patterns of standing waves in their webs (vibrations /matter/ to
spiders).  Almost any species might naturally record meaning as structures in a
very-high dimensional space -- smell is far more universal on Earth than
vision.

([**] BTW, it seems to me that musical notation is in Unicode because people
want to write /about/ music, not in order to /express/ music per se.)

Your (snipped) point about Unicode assuming sequence is well-taken.  Some human
written languages don't make much use of sequence.  I can't remember which
off-hand, but some of the old South American languages just bung a number of
symbols/pictures together into a cartoon-like frame, and leave it to the reader
to work out which express a meaning and which qualifies what.  It's an
interesting system since it allows a lot of freedom for the writer to be
creative with the pictures and layout.  I don't know how such systems would be
mapped into Unicode.  It'd be possible, I suppose, to write the symbols down in
an arbitrary, or conventual, order, but I don't know if that would be any use
for scholars, who might want to preserve the spatial layout.  If not then
they'd probably be better off using JPEGs instead of Unicode text.

I /think/ I may have worked out where we're seeing Unicode differently.
There's a parallel with dictionaries, which come in two broad flavours.  There
are the dictionaries which attempt to /record/ what the (written or not)
language is like at a given time and place (or over a range of such).  The OED
is the incomparable exemplar of this school of thought.  And then there are the
/prescriptive/ dictionaries -- ones which attempt to tell readers what the
"correct" meaning and spelling of a word is.   In the dictionary world the
prescriptive idea has long gone out of fashion[***], and prescriptive
dictionaries are only used for teaching purposes.  So, if people start --
say -- confusing "convince" and "persuade", the dictionaries will simply
reflect that in their next edition, whereas a school dictionary will attempt to
dictate that the two words have separate meanings (with a small amount of
overlap).

The parallel here is that I think you are seeing Unicode as non-prescriptive in
that sense, whereas I see it as essentially prescriptive.  It's purpose -- as I
see it --  is not to /record/ the diversity of the worlds scripts, but to
/standardise/ their computerised representation.  The motive is purely
practical, with no scholarly side to it at all. (Although considerable
scholarship goes into creating it, and it is intended to be used /by/
scholars.)   The purpose is only to allow people to share written texts across
different computers -- and for that a prescriptive approach is necessary.  A
/standard/.

([***] Since about Samuel Johnson's time, although the idea does resurface from
time to time -- I believe the original Webster's Dictionary was primarily
prescriptive.)

   -- chris