Re: [idn] call for comments for REORDERING

["Mark Davis" <mark@macchiato.com>]

1. The compatibility hangul jamo are not the preferred way to express
isolated jamo in Unicode. That would be by the use of conjoining jamo with
fillers. If the preferred forms are used, there are no problems.

2. NFC does not combine ancient Hangul into syllables because there are no
syllables that have ancient Hangul in them. It does combine as many modern
Jamo as possible into syllables. That does not -- at all -- prevent the use
of NFC with ancient Hangul.

Mark
—————

Δός μοι ποῦ στῶ, καὶ κινῶ τὴν γῆν — Ἀρχιμήδης
[http://www.macchiato.com]

----- Original Message -----
From: "Soobok Lee" <lsb@postel.co.kr>
To: "Karlsson Kent - keka" <keka@im.se>; <idn@ops.ietf.org>
Cc: "Martin Duerst" <duerst@w3.org>; <DougEwell2@cs.com>
Sent: Monday, October 22, 2001 11:40
Subject: Re: [idn] call for comments for REORDERING



----- Original Message -----
From: "Karlsson Kent - keka" <keka@im.se>
>
> > I know current NFC/NFKC has *severely flawed* hangul jamo
>
> Now that's a new complaint.  At least to me.  Not even the
> delegations from DPRK complain about that. (And they have
> all sorts of complaints.)  Do you care to say a little bit
> more about what you mean?  Or are we just to take your word
> for it?  There was a problem in earlier drafts of UAX 15
> concerning Hangul and NFKC (Hangul syllables were not preserved),
> but that problem was removed before that UTR became a UAX.

two problems:

 1) NFKC maps   compatibility hangul jamo (U+32??) into
                conjoining hangul jamo without fillers.
    That converts compat hangul jamo sequences into conjoining
      jamo sequences and they are combined partially in some cases
        by the NFC following  compatibilty decomposition.
    Modern hangul informal texts contains compatibiilty jamos very often.
    If the texts contains choseong + jungseong sequence in compat jamo,
       they will be affected by this fault.
    This fault was found by Soobok Lee, too lately.

 2) NFC  does not combine  archaic(old) hangul trailing jamo into the
     preceding half-combined syllable (from choseong jamo + jungseong jamo),
      but leave it alone as an isolated conjoining jamo.
    That means archail hangul syllable which has old hangul trailing jamo
      cannot be preserved through out NFKC.
    NFKC cannot be used for scholarly texts which contains archail hangul
      syllables.  This fault was found by Martin, too lately.

Mark and Martin knew and told me why this happened.
Martin, would you comment on this?

Soobok Lee


>
> > I hope UTC cures this BUGGY NFC/NFKC jamo handling as an
> > exceptional case while it is in  strict adherence to UTR's backward
> > compatiblity policy & promise.
>
> The normal forms for strings of already allocated characters
> will not be changed any more.
>
> Kind regards
> /Kent K
>