bug#4400: 23.1.50; char-syntax

bug#4400: 23.1.50; char-syntax

[Andreas Roehler]

Emacs -Q

(char-syntax (char-after))a
--> 119

which seems not what's told in docu:

Return the syntax code of CHARACTER, described by a character.
For example, if CHARACTER is a word constituent,
the character `w' is returned.


Thanks all!


Andreas Röhler

--
https://code.launchpad.net/s-x-emacs-werkstatt/

;;;;;;;;;;;;;;;;;;;;;;;;


In GNU Emacs 23.1.50.1 (i686-pc-linux-gnu, GTK+ Version 2.12.0)
 of 2009-07-25
Windowing system distributor `The X.Org Foundation', version 11.0.70200000
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: @im=local
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
( c h a r - s y n t a x SPC ( c h a r - a f t e r )
) a <left> C-x C-e <down> C-j q - - > SPC 1 1 9 <return>
<return> M-x r e p o r t - e m a c - b <backspace>
<backspace> s - b u <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
119
Entering debugger...
Back to top level.

Load-path shadows:
None found.

bug#4400: 23.1.50; char-syntax

[Juanma Barranquero]

On Fri, Sep 11, 2009 at 08:38, Andreas Roehler
<andreas.roehler@online.de> wrote:
>
> Emacs -Q
>
> (char-syntax (char-after))a
> --> 119
>
> which seems not what's told in docu:
>
> Return the syntax code of CHARACTER, described by a character.
> For example, if CHARACTER is a word constituent,
> the character `w' is returned.

But 119 is `w'...

ELISP> (char-syntax ?a)
119
ELISP> ?w
119

Perhaps you were expecting `char-syntax' to return a string with the
syntax code, i.e., "w"?

    Juanma

bug#4400: 23.1.50; char-syntax

[Kenichi Handa]

In article <4AA9F057.5080507@online.de>, Andreas Roehler <andreas.roehler@online.de> writes:

> Emacs -Q

> (char-syntax (char-after))a
> --> 119

> which seems not what's told in docu:

> Return the syntax code of CHARACTER, described by a character.
> For example, if CHARACTER is a word constituent,
> the character `w' is returned.

The character `w' == 119.

In Emacs, a character is represented by an integer object
(of valid character-code range).

---
Kenichi Handa
handa@m17n.org

bug#4400: 23.1.50; char-syntax

[Andreas Röhler]

Kenichi Handa wrote:
> In article <4AA9F057.5080507@online.de>, Andreas Roehler <andreas.roehler@online.de> writes:
>
>   
>> Emacs -Q
>>     
>
>   
>> (char-syntax (char-after))a
>> --> 119
>>     
>
>   
>> which seems not what's told in docu:
>>     
>
>   
>> Return the syntax code of CHARACTER, described by a character.
>> For example, if CHARACTER is a word constituent,
>> the character `w' is returned.
>>     
>
> The character `w' == 119.
>
> In Emacs, a character is represented by an integer object
> (of valid character-code range).
>
> ---
> Kenichi Handa
> handa@m17n.org
>
>
>
>
>   

Thanks.
Seems I have difficulties with understanding.
What if docu would say:

"For example, if CHARACTER is a word constituent, `119' is returned."

or maybe still better

"For example, if CHARACTER is a word constituent, numeric value of character `w' is returned, which is 
`119' in Emacs internal representation."

BTW:

Can't Emacs have more internal representations of `w' with Unicode?


Andreas

bug#4400: 23.1.50; char-syntax

[Eli Zaretskii]

> Date: Sat, 12 Sep 2009 10:31:06 +0200
> From: Andreas =?UTF-8?Q?R=C3=B6hler?= <andreas.roehler@easy-emacs.de>
> Cc: Juanma Barranquero <lekktu@gmail.com>, 4400@emacsbugs.donarmstrong.com
> 
> > In Emacs, a character is represented by an integer object
> > (of valid character-code range).
> 
> What if docu would say:
> 
> "For example, if CHARACTER is a word constituent, `119' is returned."
> 
> or maybe still better
> 
> "For example, if CHARACTER is a word constituent, numeric value of character `w' is returned, which is `119' in Emacs internal representation."

In GNU Emacs, characters and integers are one and the same.  So the
text you suggest would make things even more confusing.

A Lisp code that needs to test against character syntax class should
use ?w etc.  ?w is another way to say 119.

bug#4400: 23.1.50; char-syntax

[martin rudalics]

 > In GNU Emacs, characters and integers are one and the same.  So the
 > text you suggest would make things even more confusing.

Admittedly, the Elisp manual seems more aware of Andreas' problem and
does "use `string' to make it easier to see the character returned by
`char-syntax'".

 > A Lisp code that needs to test against character syntax class should
 > use ?w etc.  ?w is another way to say 119.

We could pretend that a person who doesn't know that should not use
`char-syntax'.  But we could also be more helpful, for example, by
providing a link to the manual.

martin

bug#4400: marked as done (23.1.50; char-syntax)

[Emacs bug Tracking System]

[-- Attachment #1: Type: text/plain, Size: 840 bytes --]

Your message dated Fri, 18 Sep 2009 19:42:22 -0400
with message-id <87pr9nom5d.fsf@stupidchicken.com>
and subject line Re: bug#4400: 23.1.50; char-syntax
has caused the Emacs bug report #4400,
regarding 23.1.50; char-syntax
to be marked as done.

This means that you claim that the problem has been dealt with.
If this is not the case it is now your responsibility to reopen the
bug report if necessary, and/or fix the problem forthwith.

(NB: If you are a system administrator and have no idea what this
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-- 
4400: http://emacsbugs.donarmstrong.com/cgi-bin/bugreport.cgi?bug=4400
Emacs Bug Tracking System
Contact owner@emacsbugs.donarmstrong.com with problems

[-- Attachment #2: Type: message/rfc822, Size: 3835 bytes --]

From: Andreas Roehler <andreas.roehler@online.de>
To: emacs-pretest-bug@gnu.org
Subject: 23.1.50; char-syntax
Date: Fri, 11 Sep 2009 08:38:15 +0200
Message-ID: <4AA9F057.5080507@online.de>


Emacs -Q

(char-syntax (char-after))a
--> 119

which seems not what's told in docu:

Return the syntax code of CHARACTER, described by a character.
For example, if CHARACTER is a word constituent,
the character `w' is returned.


Thanks all!


Andreas Röhler

--
https://code.launchpad.net/s-x-emacs-werkstatt/

;;;;;;;;;;;;;;;;;;;;;;;;


In GNU Emacs 23.1.50.1 (i686-pc-linux-gnu, GTK+ Version 2.12.0)
 of 2009-07-25
Windowing system distributor `The X.Org Foundation', version 11.0.70200000
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: de_DE.UTF-8
  value of $XMODIFIERS: @im=local
  locale-coding-system: utf-8-unix
  default-enable-multibyte-characters: t

Major mode: Lisp Interaction

Minor modes in effect:
  tooltip-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  global-auto-composition-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent input:
( c h a r - s y n t a x SPC ( c h a r - a f t e r )
) a <left> C-x C-e <down> C-j q - - > SPC 1 1 9 <return>
<return> M-x r e p o r t - e m a c - b <backspace>
<backspace> s - b u <tab> <return>

Recent messages:
For information about GNU Emacs and the GNU system, type C-h C-a.
119
Entering debugger...
Back to top level.

Load-path shadows:
None found.


[-- Attachment #3: Type: message/rfc822, Size: 2219 bytes --]

From: Chong Yidong <cyd@stupidchicken.com>
To: martin rudalics <rudalics@gmx.at>
Cc: 4400-done@emacsbugs.donarmstrong.com
Subject: Re: bug#4400: 23.1.50; char-syntax
Date: Fri, 18 Sep 2009 19:42:22 -0400
Message-ID: <87pr9nom5d.fsf@stupidchicken.com>

> > In GNU Emacs, characters and integers are one and the same.  So the
> > text you suggest would make things even more confusing.
>
> Admittedly, the Elisp manual seems more aware of Andreas' problem and
> does "use `string' to make it easier to see the character returned by
> `char-syntax'".
>
> > A Lisp code that needs to test against character syntax class should
> > use ?w etc.  ?w is another way to say 119.
>
> We could pretend that a person who doesn't know that should not use
> `char-syntax'.  But we could also be more helpful, for example, by
> providing a link to the manual.

I don't think we need to link to the manual for every function that
returns a character.  The docstring for char-syntax already states that
it returns the *character* `w' for a word constituent.