Feature request for `describe-char-after'

Feature request for `describe-char-after'

[luis fernandes]

Hello,

I would like to request that, if possible, "describe-char-after" (C-u
C-x =) also include the name of the face, the character being
described, is rendered in.

For example, if one wants to modify a particular face, one has to
find the name of the face first. So, being able to place the cursor on
the character in question and then quering everything about that
character is very convenient.

Re: Feature request for `describe-char-after'

[Juri Linkov]

luis fernandes <elf@ee.ryerson.ca> writes:
> I would like to request that, if possible, "describe-char-after" (C-u
> C-x =) also include the name of the face, the character being
> described, is rendered in.

It seems what you request for is already implemented.  For example,
C-u C-x = produces:

There are text properties here:
  fontified            t
  face                 message-header-name-face

> For example, if one wants to modify a particular face, one has to
> find the name of the face first. So, being able to place the cursor on
> the character in question and then quering everything about that
> character is very convenient.

Adding a button to the function that displays the face properties
and has a link to the customization buffer would be good.

Index: emacs/lisp/descr-text.el
===================================================================
RCS file: /cvsroot/emacs/emacs/lisp/descr-text.el,v
retrieving revision 1.17
diff -c -r1.17 descr-text.el
*** emacs/lisp/descr-text.el	9 Nov 2003 19:38:32 -0000	1.17
--- emacs/lisp/descr-text.el	22 Mar 2004 15:08:53 -0000
***************
*** 110,116 ****
  			 (setq key (pop properties)
  			       val (pop properties)
  			       len 0)
! 			 (unless (or (eq key 'category)
  				     (widgetp val))
  			   (setq val (pp-to-string val)
  				 len (length val)))
--- 110,116 ----
  			 (setq key (pop properties)
  			       val (pop properties)
  			       len 0)
! 			 (unless (or (memq key '(category face))
  				     (widgetp val))
  			   (setq val (pp-to-string val)
  				 len (length val)))
***************
*** 128,133 ****
--- 128,138 ----
  			    :notify `(lambda (&rest ignore)
  				       (describe-text-category ',value))
  			    (format "%S" value)))
+             ((eq key 'face)
+              (widget-create 'link
+                             :notify `(lambda (&rest ignore)
+                                      (describe-face ',value))
+                             (format "%S" value)))
  	    ((widgetp value)
  	     (describe-text-widget value))
  	    (t

-- 
Juri Linkov
http://www.jurta.org/emacs/

Re: Feature request for `describe-char-after'

[Juri Linkov]

BTW, I need another feature for `describe-char' - the ability
to display Unicode data for the character after point.

The saddest thing about it is that it's already implemented
but commented out with the following commentary:

;;; We cannot use the UnicodeData.txt file as such; it is not free.
;;; We can turn that info a different format and release the result
;;; as free data.  When that is done, we could reinstate the code below.
;;; For the mean time, here is a dummy placeholder.

;;; ;; We could convert the unidata file into a Lispy form once-for-all
;;; ;; and distribute it for loading on demand.  It might be made more
;;; ;; space-efficient by splitting strings word-wise and replacing them
;;; ;; with lists of symbols interned in a private obarray, e.g.
;;; ;; "LATIN SMALL LETTER A" => '(LATIN SMALL LETTER A).

I wonder why nobody has converted it into a Lisp format?
Are there any legal obstacles?

-- 
Juri Linkov
http://www.jurta.org/emacs/

Re: Feature request for `describe-char-after'

[Simon Josefsson]

Juri Linkov <juri@jurta.org> writes:

> BTW, I need another feature for `describe-char' - the ability
> to display Unicode data for the character after point.
>
> The saddest thing about it is that it's already implemented
> but commented out with the following commentary:
>
> ;;; We cannot use the UnicodeData.txt file as such; it is not free.
> ;;; We can turn that info a different format and release the result
> ;;; as free data.  When that is done, we could reinstate the code below.
> ;;; For the mean time, here is a dummy placeholder.

Could someone please explain exactly what it is in the license that
make it non-free?  Perhaps the above statement isn't accurate any
more, I believe the license has changed over time.  If some term make
the file non-free, I can forward this problem to someone at Unicode
Inc. that responded to my request to change the Unihan license earlier
(which was completely non-free).

I'm quoting http://www.unicode.org/Public/4.0-Update/UCD-4.0.0.html
with the current license terms below.

UCD Terms of Use
Disclaimer

The Unicode Character Database is provided as is by Unicode, Inc. No
claims are made as to fitness for any particular purpose. No
warranties of any kind are expressed or implied. The recipient agrees
to determine applicability of information provided. If this file has
been purchased on magnetic or optical media from Unicode, Inc., the
sole remedy for any claim will be exchange of defective media within
90 days of receipt.

This disclaimer is applicable for all other data files accompanying
the Unicode Character Database, some of which have been compiled by
the Unicode Consortium, and some of which have been supplied by other
sources.

Limitations on Rights to Redistribute This Data

Recipient is granted the right to make copies in any form for internal
distribution and to freely use the information supplied in the
creation of products supporting the UnicodeTM Standard. The files in
the Unicode Character Database can be redistributed to third parties
or other organizations (whether for profit or not) as long as this
notice and the disclaimer notice are retained. Information can be
extracted from these files and used in documentation or programs, as
long as there is an accompanying notice indicating the source.

The file Unihan.txt contains older and inconsistent Terms of Use. That
language is overridden by these terms.

Re: Feature request for `describe-char-after'

[Stefan Monnier]

> Could someone please explain exactly what it is in the license that
> make it non-free?

It does not permit modification and distribution of modified versions.
I.e. it does not allow bug-fixing.


        Stefan

License of Unicode tables (was: Re: Feature request for `describe-char-after')

[Simon Josefsson]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> Could someone please explain exactly what it is in the license that
>> make it non-free?
>
> It does not permit modification and distribution of modified versions.
> I.e. it does not allow bug-fixing.

That wasn't clear to me from the license I quoted -- I'll ask if this
really is the intention with the license.  To me, the license said I
could extract information from the files and use in my application.  I
couldn't follow how that prevented me from only incorporating part of
the file, and using something else instead of that part, which
essentially is what a bug fix is.  Has any lawyer given this advice?

But in any case -- is this a realistic problem?  Do we know of any
bugs in the file?  I'd say that changing anything in the file is not
the proper solution, it would only confuse our users since we wouldn't
follow the standard in that case.  The right thing would be to report
this to Unicode Inc. and when they publish a new version of the
tables, we would incorporate it.  If we fork the standard, I think we
get an obligation to our users to document things fully, and also to
stop claiming we follow the "real" Unicode standard; I doubt we want
to go there.

Thanks.

(I have a non-Emacs interest in this question, since GNU Libidn uses
several Unicode Inc. tables.  So even if this is moving off-topic, I'd
still like to clear up the matter.  I suspect Debian would be
interested as well, as they ship several Unicode tables, and IIRC they
have some policies that say what they ship should be free, except for
the explicitly non-free packages.)

Re: License of Unicode tables (was: Re: Feature request for `describe-char-after')

[Andreas Schwab]

Simon Josefsson <jas@extundo.com> writes:

> But in any case -- is this a realistic problem?  Do we know of any
> bugs in the file?

I think the real question is whether the licence is compatible with the
GPL.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux AG, Maxfeldstraße 5, 90409 Nürnberg, Germany
Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: License of Unicode tables

[Benjamin Riefenstahl]

Hi Simon,


> Stefan Monnier <monnier@iro.umontreal.ca> writes:
>> It does not permit modification and distribution of modified
>> versions.  I.e. it does not allow bug-fixing.

Simon Josefsson <jas@extundo.com> writes:
> I couldn't follow how that prevented me from only incorporating part
> of the file, and using something else instead of that part, which
> essentially is what a bug fix is.

This is of course a political as well as a practical issue.  I'll
stick to the practical level. 

On the practical level this is a data file, and one maintained at a
public site.  I'd expect users/developers would like to import updates
directly from there.

In this situation I wouldn't *want* to fix bugs by changing it,
because such changes would be lost with the next update.  I would
rather put fixes into a second file and read that after the original
to override the orignal values.


benny

Re: License of Unicode tables

[Eli Zaretskii]

> From: Benjamin Riefenstahl <Benjamin.Riefenstahl@epost.de>
> Date: Tue, 23 Mar 2004 15:14:32 +0100
> 
> In this situation I wouldn't *want* to fix bugs by changing it,
> because such changes would be lost with the next update.

_You_, or even the Emacs projects as a whole, could decide that you
don't fix it.  But we must give the _users_ the freedom to do so, and
so all parts of Emacs we distribute must be freely modifiable and
redistributable after such modifications.

Re: License of Unicode tables

[Benjamin Riefenstahl]

Hi Eli,


>> From: Benjamin Riefenstahl <Benjamin.Riefenstahl@epost.de>
>> In this situation I wouldn't *want* to fix bugs by changing it,
>> because such changes would be lost with the next update.

Eli Zaretskii <eliz@elta.co.il> writes:
> _You_, or even the Emacs projects as a whole, could decide that you
> don't fix it.

I didn't say that.  I said, I wouldn't fix problems in this way and
than I layed out another, technically better way (IMO) to introduce
fixes.

Which leaves a completely political issue.  And I am not saying I
don't support that, just that I don't see any serious technical or
practical problem.


benny

Re: License of Unicode tables

[Eli Zaretskii]

> From: Benjamin Riefenstahl <Benjamin.Riefenstahl@epost.de>
> Date: Wed, 24 Mar 2004 15:05:53 +0100
> 
> Which leaves a completely political issue.

I don't think that sticking to a principle is ``a completely political
issue'', but that's probably just semantics.

Re: License of Unicode tables (was: Re: Feature request for `describe-char-after')

[Eli Zaretskii]

> From: Simon Josefsson <jas@extundo.com>
> Date: Tue, 23 Mar 2004 14:27:17 +0100
> 
> But in any case -- is this a realistic problem?  Do we know of any
> bugs in the file?

IMHO, it doesn't matter.  A user could wish to modify the file for any
number of reasons, and the GNU project is committed to giving them
this freedom, even if they use that freedom to hang themselves.

Re: License of Unicode tables (was: Re: Feature request for `describe-char-after')

[Richard Stallman]

    But in any case -- is this a realistic problem?  Do we know of any
    bugs in the file?

The question is not relevant; we can't accept a non-free file
on the grounds that its contents are perfect for its job.
There may be a way to rescue the use of this file.
I am looking into it.

Re: License of Unicode tables

[Simon Josefsson]

Richard Stallman <rms@gnu.org> writes:

>     But in any case -- is this a realistic problem?  Do we know of any
>     bugs in the file?
>
> The question is not relevant; we can't accept a non-free file
> on the grounds that its contents are perfect for its job.
> There may be a way to rescue the use of this file.
> I am looking into it.

Unicode 4.0.1 was just released.  The licensing terms has changed, and
if I'm locating the proper license terms for the data files (the files
themselves does not appear to include the license), it now reads as
below.  This is better, as it allows for redistribution of modified
copies, isn't it?


Copyright © 1991-2004 Unicode, Inc. All rights reserved. Distributed
under the Terms of Use in http://www.unicode.org/copyright.html.

Permission is hereby granted, free of charge, to any person obtaining
a copy of the Unicode data files and associated documentation (the
"Data Files") or Unicode software and associated documentation (the
"Software") to deal in the Data Files or Software without restriction,
including without limitation the rights to use, copy, modify, merge,
publish, distribute, and/or sell copies of the Data Files or Software,
and to permit persons to whom the Data Files or Software are furnished
to do so, provided that (a) the above copyright notice(s) and this
permission notice appear in all copies of the Data Files or Software,
(b) both the above copyright notice(s) and this permission notice
appear in associated documentation, and (c) there is clear notice in
each modified Data File or in the Software as well as in the
documentation associated with the Data File(s) or Software that the
data or software has been modified.

THE DATA FILES AND SOFTWARE ARE PROVIDED "AS IS", WITHOUT WARRANTY OF
ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT
HOLDER OR HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR
ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THE DATA FILES OR
SOFTWARE.

Except as contained in this notice, the name of a copyright holder
shall not be used in advertising or otherwise to promote the sale, use
or other dealings in these Data Files or Software without prior
written authorization of the copyright holder.

Re: License of Unicode tables

[Richard Stallman]

This is a free license, and even compatible with the GPL (if that ever
matters).  Yes, we can use it now.

Re: License of Unicode tables (was: Re: Feature request for `describe-char-after')

[Thien-Thi Nguyen]

Simon Josefsson <jas@extundo.com> writes:

   I couldn't follow how that prevented me from only incorporating
   part of the file, and using something else instead of that
   part, which essentially is what a bug fix is.

a bugfix implies modification and (re)distribution of the source.
what you describe can be called a bugfix but is often called a
"workaround": a local modification that does not benefit others
outside your organizational scope.

thi

Re: Feature request for `describe-char-after'

[Richard Stallman]

I asked someone to work on handling UnicodeData.txt as needed, for the
GNU Miscfiles.  I will see if he finished this task.