Re: Feature needed

[Stephen J. Turnbull]

James Cloos writes:
 > >>>>> "DH" == Davis Herring <address@hidden> writes:
 > 
 > >> `C-u C-x =' displays this information.  For instance,
 > >> 
 > >> character: Ä (196, #o304, #xc4)
 > >> to input: type "\"{A}" or "\"A" with TeX
 > >> 
 > >> where the name of the input method has a link to its description.
 > 
 > DH> Doesn't it only check the current input method?
 > 
 > Indeed.  And even then it does't always report.  [See below.]
 > 
 > Checking every input method might be too ram or i/o intensive for all
 > users, but would make a reasonable option.

No, it's not.  The vast majority of character inputs are embedded in
self-modifying tries, ie, East Asian phonetic input for Han ideographs
in complex system-wide servers.  I don't see how you plan to get this
information out of SCIM/Anthy, for example, or Xlib/XIM for Greek for
that matter.

I really don't understand the purpose of this request.  If you can
*see* a character in Emacs, with few exceptions you can copy it (and
if you can't copy it, you won't be able to query it for properties,
either).  You can also get its Unicode code point, and then make-char
wins.  So for one-off situations (eg, a particular math character or 
παν語) you can make your own input method (put the thing in a
register).

Regular users will know how to use some input method, pretty much by
definition.  So really we're talking language learners (FVO "language"
including "math and science notation").  If people want to write
language tutorials in Emacs Lisp, great!  But I don't think that just
providing input method advice is particularly valuable.

For math and science, TeX wins.  The current C-x = will give that, it
seems.

For Japanese and Korean, if you can say it, you can type it.  So the
information you need to type 語 is the reading "go" (and most Japanese
prefer entering the Roman letters g o, while Koreans prefer a Hangul
keyboard but can use Roman letters, so this works on the bare minimum
keyboard such as the Happy Hacker).

For Chinese, I don't know, but I believe that essentially all
computer-using Chinese can handle Mandarin or Cantonese, and both of
those have phonetic input methods (how tones are handled, I'm not
sure).

For non-Han-using natural languages, Emacs users mostly use ISO Level
3 shift (which would be a pain to deal with) or Quail.  Point to the
language's registered Quail input method -- which can display one or
two pages of keystroke mappings -- and add a note that there may be
other methods that the user may prefer.

That leaves languages like Thai and Devanagari, which leaves me
out. :-)  Handa-san?

I don't think the current "to input, use:" feature should be removed,
but I think that teaching people how to use any input method that
happens to be available on the host is beyond Emacs' scope.

Note that trying to infer language from characters is probably not a
great idea, either, given the amount of overlap of non-ASCII
characters: far greater than 0%, far less than 100%.  But it's pretty
likely that the character the user wants to know about can't be input
using the current input method, either, I should think.