On May 15 00:58, IWAMURO Motonori wrote:
2009/5/13 Corinna Vinschen <vinschen@redhat.com>:
http://www.cl.cam.ac.uk/~mgk25/ucs/wcwidth.c
This looks nice.
Do you import Markus Kuhn's wcwidth implementation?
Trouble is, there's the thorny issue of the "CJK Ambiguous Width"
category of characters, which consists of things like Greek and
Cyrillic letters as well as line drawing symbols. Those have a width
of 1 in Western use, yet with CJK fonts they have a width of 2. That's
why Markus Kuhn's code includes the mk_wcswidth_cjk() variant.
We should use the standard variation alone, imho.
I don't think so.
1) It is very very inconvenient for me :-)
(Now, I apply the local patch of CJK width support to cygwin1.dll in
my environment.)
2) Unicode Standard Annex #11
http://www.unicode.org/unicode/reports/tr11/ recommends:
5 Recommendations
(snip)
When processing or displaying data
(snip)
Ambiguous characters behave like wide or narrow characters depending
on the context (language tag, script identification, associated
font, source of data, or explicit markup; all can provide the
context). If the context cannot be established reliably, they should
be treated as narrow characters by default.
The recommendation is independent of legacy encoding.
I think that a new locale category that specifies the "context" is necessary.
Because the "context" influences only the display or text layout.
However, there is no such standard now.
Therefore, I propose to use *_cjk() when the language part of LC_CTYPE
is 'ja', 'ko', 'vi' or 'zh'.
That would be fine with me, but tests for the actual language are not
used anywhere in newlib, so that's something very new. Can we check in my patch for the time being and
extend it with the CJK variation later? I will not be available for the
next two weeks, but I'd be glad if at least the default variation can go
in so I can create another Cygwin test release before I'm offline.