From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <4d11e29c8ac6819bed2e1a1e6d6da764@quanstro.net>
Date: Fri, 19 May 2006 19:44:56 -0500
From: quanstro@quanstro.net
To: 9fans@cse.psu.edu
Subject: Re: [9fans] combining characters
In-Reply-To: <20060520004344.GI14448@submarine>
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On Fri May 19 19:45:43 CDT 2006, rvs@sun.com wrote:
>   There's no such thing as an accented letter in a Russian language.
>   That was the exact point of my initial remark.

the text was /romanized/ russian names.  it was not written in the cyrill=
ic=20
alphabet.

>=20
>   Now, if you allow me to educate myself in Unicode a little bit,
>   I'm about to follow through with your example. Be patient with me ;-)

as long as you're patient with me.

>=20
> > suppose that U+x is the cp for the letter. =20
> > suppose U+y is the cp for the accent.
>=20
>   Ok.
>=20
> > suppose that we're lucky and there exists U+w ? U+xU+y. =20
>=20
>   Just to make sure I still follow: U+w is supposed to *visually*=20
>   look like U+x followed by U+y, right ?

yes.  they must be the same.

>=20
> > then U+w should be the same glyph as U+xU+y.
>=20
>   The same glyph from a visual standpoint, right ?

a glyph IS the visual representation.=20

>=20
> > cannonical composition would yield
> > 	compose(U+xU+y)	U+w
> > 	compose(U+w)		U+w
> > while cannonical decompostion would yield
> > 	decompose(U+xU+y)	U+xU+y
> > 	decompose(U+w)		U+xU+y
>=20
>   And that's exactly the place where I think Unicode goes against commo=
n
>   sense and language rules. I would expect it to mandate that a *decomp=
osable*
>   character is supposed to be used over the decomposition. Which in you=
r
>   original example was the case.

rob agrees with you.

however, there is a big advantage to a composed character -- you don't ha=
ve to figure out
how to stick the horn, breve, slash, &c on top of, under, on the shoulder=
 of, through, &c
the original character.  in plan 9, characters are bitmaps making this op=
eration extra
annoying.  also, there are no rules in unicode preventing /arbitrary/ com=
positions.
this is valid unicode
	u+0069 u+0300 u+0301 u+0302 u+0303
all those combining codepoints attach to the base cp u+0069.  figure out =
how to build that
glyph.

>=20
>   "There are no accents in Russian language" (*)
>

now you're confusing language and alphabet! =E2=98=BA

- erik