Re: Re: Big5 "mostly" complete

[Rich Felker <dalias@aerifal.cx>]

On Sun, Aug 18, 2013 at 12:20:47PM +0800, Roy wrote:
> Both Big5-UAO and Big5-HKSCS are needed for those Taiwan people and
> Hong Kong people.
> For Big5-UAO, there is some commonly used dingbats(for example "♡"
> mark) and numeric representations(for example "①") are in Big5-UAO
> but not in CP950.
> and Big5-UAO is still being used not only in ptt.cc telnet BBS, but
> also in  text data files(file lists/cue sheets) because of
> not-supporting UTF-8 in applications(for example, Perl File-system
> I/O in windows, CD-Rippers).
> for Big5-HKSCS, it use used for storing commonly used Cantonese
> ideographs (for example, "𨋢" means "lift" in Cantonese) in Hong
> Kong.

HKSCS is supported as of yesterday's commit. I'm aware that it's
needed for representing Cantonese language in Big5, and that it's
widely used on the web.

What I'm not clear on is the necessity of UAO. Keep in mind that iconv
is an API for information interchange: things like interpreting web
content, email, old text files, etc. The fact that UAO exists is not
alone reason to support it; it has to actually have usefulness in
situations where the iconv interface should be used. If you want to
see it included, this is what you need to convince us of:

- That it's in widespread use in large volumes of existing data (on
  the web, text files, etc.) or data that is being newly generated
  (e.g. as a default encoding of popular mail software).

- That it's necessary to represent linguistic content in languages
  used in Taiwan, not just as a substitute for Unicode to represent
  foreign languages.

- That failure to support it would put musl's iconv in a worse
  position of compatibility than other iconv implementations or
  software-specific (e.g. in-browser) character set conversions.

The fact that UAO does not even have a MIME type, and that, per web
standards (http://encoding.spec.whatwg.org/), a MIME type of "Big5" is
to be interpreted as essentially Big5-2003+HKSCS, leaves me doubting
that UAO is in widespread use for information interchange. Mozilla
seems to be the only browser that support it. I previously cited a
thread on the whatwg mailing list in which research was being
conducted to determine what should constitute Big5, i.e. roughly what
characters outside the old CP950 were needed for real websites, and
UAO did not come up.

If I'm wrong and just missing its importance, please fill me in. I'm
not trying to be difficult, but if UAO is important, I want to see the
reasons why.

Rich