Re: Cyrillic vs UTF-8

[Kenichi Handa]

In article <address@hidden>, Richard Stallman <address@hidden> writes:
>     By the way, all these problems are solved in emacs-unicode.

> Could you report on what work is needed before we
> can release this code?

Dave has compiled the current problems in the file
emacs-unicode/README.unicode.  Some of them (especially
serious ones) are already fixed.

Dave, do you have anything else to add to that file?

I think the most difficult task for releasing that code is
to merge the changes into HEAD.  Emacs-unicode was branched
on 2002-03-01, and since then, there were a lot of changes
in HEAD.

---
Ken'ichi HANDA
address@hidden


--- README.unicode ---
                                            -*-mode: text; coding: latin-1;-*-

Problems, fixmes and other issues in the emacs-unicode branch
-------------------------------------------------------------

Notes by fx to record various things of variable importance.  handa
needs to check them -- don't take too seriously, especially with
regard to completeness.

_Do take seriously that you don't want this branch unless you're
actually working on it; you risk your data by actually using it._  If
you just want to edit Unicode and/or unify iso-8859 et al, see the
existing support and the extra stuff at
<URL:ftp://dlpx1.dl.ac.uk/fx/emacs/Mule>, mostly now in the CVS trunk.
(Editing support is mostly orthogonal to the internal representation.)

 * SINGLE_BYTE_CHAR_P returns true for Latin-1 characters, which has
   undesirable effects.  E.g.:
   (multibyte-string-p (let ((s "x")) (aset s 0 ?£) s)) => nil
   (multibyte-string-p (concat [?£])) => nil
   (text-char-description ?£) => "M-#"

        These examples are all fixed by the change of 2002-10-14, but
        there still exist questionalble SINGLE_BYTE_CHAR_P in the
        code.

 * Rationalize character syntax and its relationship to the Unicode
   database.  (Applies mainly to symbol an punctuation syntax.)

 * Fontset handling and customization needs work.  We want to relate
   fonts to scripts, probably based on the Unicode blocks.  The
   presence of small-repertoire 10646-encoded fonts in XFree 4 is a
   pain, not currently worked round.

        With the change on 2002-07-26, multiple fonts can be
        specified in a fontset for a specific range of characters.
        Each range can also be specified by script.  Before using
        ISO10646 fonts, Emacs checks their repertories to avoid such
        fonts that don't have a glyph for a specific character.

 * Work is also needed on charset and coding system priorities.

 * The relevant bits of latin1-disp.el need porting (and probably
   re-naming/updating).  See also cyril-util.el.

 * Quail files need more work now the encoding is irrelevant.

 * What to do with the old coding categories stuff?

 * The preferred-coding-system property of charsets should probably be
   junked unless it can be made more useful now.

 * find-multibyte-characters needs looking at.

 * Implement Korean cp949/UHC, BIG5-HKSCS and any other important missing
   charsets.

 * Check up on definition of alternativnj.

 * Lazy-load tables for unify-charset somehow?

        Actually, Emacs clear out all charset maps and unify-map just
        before dumping, and their are loaded again on demand the
        dumped emacs.  But, those maps (char tables) generated while
        temacs is running can't be get rid of from the dumped emacs.

 * Translation tables for {en,de}code currently aren't supported.

        This should be fixed by the changes of 2002-10-14.

 * Defining CCL coding systems currently doesn't work.

        This should be fixed by the changes of 2003-01-30.

 * iso-2022 charsets get unified on i/o.

        With the change on 2003-01-06, decoding routines put `charset'
        property to decoded text, and iso-2022 encoder pay attention
        to it.  Thus, for instance, reading and writing by
        iso-2022-7bit preserve the original designation sequences.
        The property name `preferred-charset' may be better?

        We may have to utilize this property to decide a font.

 * Revisit locale processing: look at treating the language and
   charset parts separately.  (Language should affect things like
   speling and calendar, but that's not a Unicode issue.)

 * Handle Unicode combining characters usefully, e.g. diacritics, and
   handle more scripts specifically (Ã  la Devanagari).  There are
   issues with canonicalization.

 * Bidi is a separate issue with no support currently.

 * We need tabular input methods, e.g. for maths symbols.  (Not
   specific to Unicode.)

 * Need multibyte text in menus, e.g. for the above.  (Not specific to
   Unicode.)

 * There's currently no support for Unicode normalization.

 * Populate char-width-table correctly for Unicode chanaracters and
   worry about what happens when double-width charsets covering
   non-CJK characters are unified.

 * Emacs 20/21 .elc files are currently not loadable.  It may or may
   not be possible to do this properly.

        With the change on 2002-07-24, elc files generated by Emacs
        20.3 and later are correctly loaded (including those
        containing multibyte characters and compressed).  But, elc
        files generated by 20.2 and the primer are still not loadable.
        Is it really worth working on it?

 * Rmail won't work with non-ASCII text.  Encoding issues for Babyl
   files need sorting out, but rms says Babyl will go before this is
   released.

 * Gnus still needs some attention, and we need to get changes
   accepted by Gnus maintainers...

 * There are type errors lurking, e.g. in
   Fcheck_coding_systems_region.  Define ENABLE_CHECKING to find them.

 * You can grep the code for lots of fixmes.

 * Old auto-save files, and similar files, such as Gnus drafts,
   containing non-ASCII characters probably won't be re-read correctly.