Learning emacs sources

Learning emacs sources

[tiefeng wu]

Hello emacs developers!

I'm interesting to know implementation of emacs.
I downloaded source of version 22.3, but honestly,
source files are too complicated for me.

Any introduce view of emacs structure design or
any advise will be appreciated.

I'm sorry if I'm asking in wrong place or it's sound
stupid for you :)

tiefeng wu
2009-07-29

Re: Learning emacs sources

[Chong Yidong]

tiefeng wu <icebergwtf@gmail.com> writes:

> I'm interesting to know implementation of emacs.  I downloaded source
> of version 22.3, but honestly, source files are too complicated for
> me.
>
> Any introduce view of emacs structure design or any advise will be
> appreciated.

Reading the source in one go is probably not feasible.  If you are
interested in how one particular part of Emacs works, a good strategy is
to read the relevant part of the Lisp manual, try to formulate a set of
specific questions, then ask this mailing list.

Re: Learning emacs sources

[Stephen J. Turnbull]

Chong Yidong writes:
 > tiefeng wu <icebergwtf@gmail.com> writes:
 > 
 > > I'm interesting to know implementation of emacs.  I downloaded source
 > > of version 22.3, but honestly, source files are too complicated for
 > > me.
 > >
 > > Any introduce view of emacs structure design or any advise will be
 > > appreciated.
 > 
 > Reading the source in one go is probably not feasible.  If you are
 > interested in how one particular part of Emacs works, a good strategy is
 > to read the relevant part of the Lisp manual, try to formulate a set of
 > specific questions, then ask this mailing list.

If you want to understand the design overview, then

    http://www.gnu.org/software/emacs/emacs-paper.html

(the basic textbook for "Emacs 101", authored by Richard Stallman) and

    http://www.xemacs.org/Documentation/21.5/html/internals_14.html

(somewhat more implementation-specific and up-to-date) are good
summaries.  For internals from the inside out the latter is a good
place to start.  You will find that implementation details are
somewhat divergent from (GNU) Emacs, but important things like naming
conventions (eg, 'why do identifiers start with "Q", "S", "V", or
"F"?') and the relation of the Emacs event loop to the traditional
read-eval-print loop are gathered in one convenient place here.  When
you start recognizing divergences between the XEmacs docs and the
Emacs implementation, you can be pretty sure you've understood enough
to switch to just reading Emacs source. :-)

Re: Learning emacs sources

[tiefeng wu]

2009/7/29 Stephen J. Turnbull <stephen@xemacs.org>:
> Chong Yidong writes:
>  > Reading the source in one go is probably not feasible.  If you are
>  > interested in how one particular part of Emacs works, a good strategy is
>  > to read the relevant part of the Lisp manual, try to formulate a set of
>  > specific questions, then ask this mailing list.
>
> If you want to understand the design overview, then
>
>    http://www.gnu.org/software/emacs/emacs-paper.html
>
> (the basic textbook for "Emacs 101", authored by Richard Stallman) and
>
>    http://www.xemacs.org/Documentation/21.5/html/internals_14.html
>
> ...

Thank you both YiDong and Stephen for your attentions. Your replies
are very helpful.
I'll have more specific questions next time :-)

tiefeng wu
2009-07-29

Re: Learning emacs sources

[Sean Sieger]

"Stephen J. Turnbull" <stephen@xemacs.org> writes:

    If you want to understand the design overview, then

        http://www.gnu.org/software/emacs/emacs-paper.html

    (the basic textbook for "Emacs 101", authored by Richard Stallman)

Wow. Thank you for this, though right under my nose for a decade I've
never heard of this.

Re: Learning emacs sources

[Stephen J. Turnbull]

Sean Sieger writes:
 > "Stephen J. Turnbull" <stephen@xemacs.org> writes:
 > 
 >     If you want to understand the design overview, then
 > 
 >         http://www.gnu.org/software/emacs/emacs-paper.html
 > 
 >     (the basic textbook for "Emacs 101", authored by Richard Stallman)
 > 
 > Wow. Thank you for this, though right under my nose for a decade I've
 > never heard of this.

Thank Richard!

I've never understood why it isn't distributed with Emacs, though.  If
necessary (like the GNU Manifesto) it could be marked "of great
historical interest though implementation details differ today".

Re: Learning emacs sources

[Sundar Vasan]

On Tue, Jul 28, 2009 at 8:22 PM, Chong Yidong<cyd@stupidchicken.com> wrote:
> Reading the source in one go is probably not feasible.  If you are
> interested in how one particular part of Emacs works, a good strategy is
> to read the relevant part of the Lisp manual, try to formulate a set of
> specific questions, then ask this mailing list.
>

Are there any simple bugs that I could work on? That would give me a
lot more focus than just looking randomly.

Adding/updating docs is something else that I was thinking about as a
good way to start (esp since I can look at it from a newbie
perspective as I'm fairly new to emacs). That would also help me learn
more about emacs. But I'm not sure where to begin. Any suggestions?

Re: Learning emacs sources

[Lennart Borgman]

On Thu, Jul 30, 2009 at 12:06 AM, Sundar Vasan<vr.sundar@gmail.com> wrote:
> On Tue, Jul 28, 2009 at 8:22 PM, Chong Yidong<cyd@stupidchicken.com> wrote:
>> Reading the source in one go is probably not feasible.  If you are
>> interested in how one particular part of Emacs works, a good strategy is
>> to read the relevant part of the Lisp manual, try to formulate a set of
>> specific questions, then ask this mailing list.
>>
>
> Are there any simple bugs that I could work on? That would give me a
> lot more focus than just looking randomly.
>
> Adding/updating docs is something else that I was thinking about as a
> good way to start (esp since I can look at it from a newbie
> perspective as I'm fairly new to emacs). That would also help me learn
> more about emacs. But I'm not sure where to begin. Any suggestions?


Do you know about the bug database:

    http://emacsbugs.donarmstrong.com/

Even if you can't solve the bugs right now, looking at them and trying
to understand might perhaps be something that fits your mind.

Another thing to look at (that is quite a bit complicated though) is
CEDET that is on its way into Emacs. There are plenty of things to do.

Re: Learning emacs sources

[Sundar Vasan]

On Wed, Jul 29, 2009 at 3:19 PM, Lennart
Borgman<lennart.borgman@gmail.com> wrote:
> Do you know about the bug database:
>
>    http://emacsbugs.donarmstrong.com/
>
> Even if you can't solve the bugs right now, looking at them and trying
> to understand might perhaps be something that fits your mind.

I knew about it but hadn't looked through it in detail. I took another
look and saw a bug (3849) for eshell (lack of) documentation.  That
would work. I saw a couple more that looked interesting. Thanks!

> Another thing to look at (that is quite a bit complicated though) is
> CEDET that is on its way into Emacs. There are plenty of things to do.

Ok, that sounds interesting. I tried ECB + CEDET about a year ago and
found it very hard to use at that point. Felt like I had to really
understand them to be able to use them instead of just being able to
use them. I was also just then starting to try out Emacs so that
probably made it worse. I haven't tried it recently though I read that
a new version of both were released.