bug#10502: 24.0.92; Please add optional NAMES arg to `read-char-by-name'

bug#10502: 24.0.92; Please add optional NAMES arg to `read-char-by-name'

[Drew Adams]

The use of `(ucs-names)' is hard-coded in `read-char-by-name'.  Please
add an optional parameter NAMES that defaults to `(ucs-names)' and use
that instead.  That will enable callers to use a different set of
candidates, typically a subset of `(ucs-names)'.
 
`ucs-names' is gigantic and all-emcompassing.  Code that calls
`read-char-by-name' for a particular purpose/context might well deal
with only a subset of that giant set of char names.  The names it deals
with should not be hard-coded but should be decidable programmatically.

In GNU Emacs 24.0.92.1 (i386-mingw-nt5.1.2600) of 2012-01-05 on MARVIN
 Windowing system distributor `Microsoft Corp.', version 5.1.2600
 configured using `configure --with-gcc (4.6) --no-opt --cflags
 -ID:/devel/emacs/libs/libXpm-3.5.8/include
 -ID:/devel/emacs/libs/libXpm-3.5.8/src
 -ID:/devel/emacs/libs/libpng-dev_1.4.3-1/include
 -ID:/devel/emacs/libs/zlib-dev_1.2.5-2/include
 -ID:/devel/emacs/libs/giflib-4.1.4-1/include
 -ID:/devel/emacs/libs/jpeg-6b-4/include
 -ID:/devel/emacs/libs/tiff-3.8.2-1/include
 -ID:/devel/emacs/libs/gnutls-3.0.9/include --ldflags
 -LD:/devel/emacs/libs/gnutls-3.0.9/lib'
 

bug#10502: 24.0.92; Please add optional NAMES arg to `read-char-by-name'

[Lars Ingebrigtsen]

"Drew Adams" <drew.adams@oracle.com> writes:

> The use of `(ucs-names)' is hard-coded in `read-char-by-name'.  Please
> add an optional parameter NAMES that defaults to `(ucs-names)' and use
> that instead.  That will enable callers to use a different set of
> candidates, typically a subset of `(ucs-names)'.

I don't think so.  `read-char-by-name' is just a shim over

(completing-read
 prompt
 (lambda (string pred action)
   (if (eq action 'metadata)
       '(metadata
         (annotation-function . mule--ucs-names-annotation)
         (category . unicode-name))
     (complete-with-action action (ucs-names) string pred))))

and if you want a different completion table, then you should just avoid
`read-char-by-name' -- it doesn't provide much value.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#10502: 24.0.92; Please add optional NAMES arg to `read-char-by-name'

[Drew Adams]

> > The use of `(ucs-names)' is hard-coded in `read-char-by-name'.  Please
> > add an optional parameter NAMES that defaults to `(ucs-names)' and use
> > that instead.  That will enable callers to use a different set of
> > candidates, typically a subset of `(ucs-names)'.
> 
> I don't think so.  `read-char-by-name' is just a shim over
> 
> (completing-read
>  prompt
>  (lambda (string pred action)
>    (if (eq action 'metadata)
>        '(metadata
>          (annotation-function . mule--ucs-names-annotation)
>          (category . unicode-name))
>      (complete-with-action action (ucs-names) string pred))))
> 
> and if you want a different completion table, then you should just avoid
> `read-char-by-name' -- it doesn't provide much value.

No.  `read-char-by-name' is useful generally.  It is a general
function for reading a character by its Unicode name.  Nothing
about that means that the full set of Unicode names need
necessarily be the set to choose from.  The function becomes
far more useful if a caller can specify the set of chars to
use as the domain.