From: "alin.s" <alinsoar@voila.fr>
To: Emacs-devel@gnu.org
Subject: Re: Watchpoints for emacs lisp.
Date: Sat, 15 May 2010 04:24:05 -0700 (PDT) [thread overview]
Message-ID: <28567697.post@talk.nabble.com> (raw)
In-Reply-To: <28567671.post@talk.nabble.com>
alin.s wrote:
>
>
>
> Stefan Monnier wrote:
>>
>>> I insert to the struct Lisp_Symbol a field :watched: .
>>
>> I think a good starting point is to use the existing `constant'
>> field and just add a special WATCHED value to it (it already has 2bits
>> but only uses 1, so you don't even need to make the field any larger).
>>
>>
>
> Here is the symbol structure. Can you point your finger on the unused bit
> ?
>
>
> /* In a symbol, the markbit of the plist is used as the gc mark bit */
>
> struct Lisp_Symbol
> {
> unsigned gcmarkbit : 1;
>
> /* Non-zero means symbol serves as a variable alias. The symbol
> holding the real value is found in the value slot. */
> unsigned indirect_variable : 1;
>
> /* Non-zero means symbol is constant, i.e. changing its value
> should signal an error. */
> unsigned constant : 1;
>
> /* Interned state of the symbol. This is an enumerator from
> enum symbol_interned. */
> unsigned interned : 2;
>
> /* The symbol's name, as a Lisp string.
>
> The name "xname" is used to intentionally break code referring to
> the old field "name" of type pointer to struct Lisp_String. */
> Lisp_Object xname;
>
> /* Value of the symbol or Qunbound if unbound. If this symbol is a
> defvaralias, `value' contains the symbol for which it is an
> alias. Use the SYMBOL_VALUE and SET_SYMBOL_VALUE macros to get
> and set a symbol's value, to take defvaralias into account. */
> Lisp_Object value;
>
> /* Function value of the symbol or Qunbound if not fboundp. */
> Lisp_Object function;
>
> /* The symbol's property list. */
> Lisp_Object plist;
>
> /* Next symbol in obarray bucket, if the symbol is interned. */
> struct Lisp_Symbol *next;
> };
>
>
I see 3 free bits here: 1+1+1+2 =5.
(the bits 6-7-8 are free).
Why do you say that it's impossible to insert a new field :watch: there ? It
takes 2 values, so it will rest 2 free bits.
--
View this message in context: http://old.nabble.com/Watchpoints-for-emacs-lisp.-tp28512483p28567697.html
Sent from the Emacs - Dev mailing list archive at Nabble.com.
next prev parent reply other threads:[~2010-05-15 11:24 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-10 16:28 Watchpoints for emacs lisp alin.s
2010-05-11 11:59 ` Richard Stallman
2010-05-11 12:54 ` alin.s
2010-05-11 13:43 ` Ken Raeburn
2010-05-11 14:10 ` Stefan Monnier
2010-05-11 15:37 ` alin.s
2010-05-15 11:16 ` alin.s
2010-05-15 11:24 ` alin.s [this message]
2010-05-15 11:44 ` alin.s
2010-05-15 11:56 ` alin.s
2010-05-15 12:43 ` Helmut Eller
2010-05-15 13:06 ` alin.s
2010-05-15 17:48 ` Stefan Monnier
2010-05-16 13:07 ` alin.s
2010-05-16 13:09 ` Lennart Borgman
2010-05-16 13:42 ` alin.s
2010-05-16 16:28 ` Lennart Borgman
2010-05-16 19:46 ` alin.s
2010-05-16 20:42 ` Stefan Monnier
2010-05-16 21:10 ` alin.s
2010-05-17 13:24 ` Stefan Monnier
2010-05-15 12:15 ` Andreas Schwab
2010-05-15 17:43 ` Stefan Monnier
2010-05-16 13:05 ` alin.s
2010-05-16 15:03 ` Chad Brown
2010-05-16 19:44 ` alin.s
2010-05-16 21:31 ` alin.s
2010-05-16 22:38 ` alin.s
2010-05-16 23:47 ` Lennart Borgman
2010-05-16 23:56 ` alin.s
2010-05-17 15:52 ` alin.s
2010-05-17 16:09 ` Lennart Borgman
2010-05-17 16:40 ` alin.s
2010-05-17 17:00 ` Lennart Borgman
2010-05-17 17:29 ` alin.s
2010-05-17 18:39 ` alin.s
2010-05-17 18:41 ` alin.s
2010-05-17 20:22 ` alin.s
2010-05-17 18:59 ` Eli Zaretskii
2010-05-17 19:04 ` Lennart Borgman
2010-05-17 19:00 ` Chad Brown
2010-05-18 8:22 ` Adrian Robert
2010-05-18 19:46 ` Chad Brown
2010-05-18 22:38 ` Andreas Schwab
2010-05-24 14:36 ` alin.s
2010-05-24 14:46 ` Ken Raeburn
2010-05-26 8:27 ` alin.s
2010-05-24 15:12 ` alin.s
2010-05-24 17:36 ` Jan Djärv
2010-05-24 17:47 ` Stefan Monnier
2010-05-26 10:38 ` alin.s
2010-05-26 13:46 ` Stefan Monnier
2010-05-26 16:49 ` alin.s
2010-05-27 14:08 ` alin.s
2010-05-27 22:05 ` Andreas Schwab
2010-05-28 20:09 ` alin.s
2010-07-06 12:26 ` alin.s
2010-08-10 11:00 ` Stefan Monnier
2010-05-29 4:25 ` tomas
2010-05-19 4:30 ` Ken Raeburn
2010-05-19 6:20 ` Adrian Robert
2010-05-17 19:56 ` Andreas Schwab
-- strict thread matches above, loose matches on Subject: below --
2010-05-11 13:54 A. Soare
2010-05-12 1:53 ` Ken Raeburn
2010-05-12 2:04 ` Stephen J. Turnbull
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=28567697.post@talk.nabble.com \
--to=alinsoar@voila.fr \
--cc=Emacs-devel@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.