A way to get a list of available functions / variables?

A way to get a list of available functions / variables?

[Taylor Venable]

Is there a way to programmatically get the list of available functions?
I'm thinking there must be a table somewhere which relates symbol names
to actual function definitions, but can you get all the names in the
table from Lisp code?  If so, my second question would then be if I
could do the same for variables.

The reason I ask is I've got this thing going on at my college where
I'll write up an Emacs "function of the day" on the whiteboard in the
computer science lounge.  It'd be cool if I could automate this process
to automatically choose a random function or variable and build like an
RSS feed of the results or something.  Because I don't know how many
times I've been just randomly browsing around the documentation or
source and found something like c-subword-mode that I otherwise would
not have known even existed!

Thanks.

-- 
Taylor Venable            http://real.metasyntax.net:2357/

foldr = lambda f, i, l: (len(l) == 1 and [f(l[0], i)] or
                         [f(l[0], foldr(f, i, l[1:]))])[0]

Re: A way to get a list of available functions / variables?

[Johannes Weiner]

Hi,

Taylor Venable <taylor@metasyntax.net> writes:

> Is there a way to programmatically get the list of available functions?
> I'm thinking there must be a table somewhere which relates symbol names
> to actual function definitions, but can you get all the names in the
> table from Lisp code?  If so, my second question would then be if I
> could do the same for variables.

mapatoms might help:

(let (cmds vars)
  (mapatoms (lambda (atom)
	      (cond
	       ((commandp atom)
		(setq cmds (cons atom cmds)))
	       ((custom-variable-p atom)
		(setq vars (cons atom vars)))))))

Or with CL functions and without distinguishing between commands and
variables:

(remove-if-not (lambda (atom)
		 (or (commandp atom)
		     (custom-variable-p atom)))
	       obarray)

> The reason I ask is I've got this thing going on at my college where
> I'll write up an Emacs "function of the day" on the whiteboard in the
> computer science lounge.  It'd be cool if I could automate this process
> to automatically choose a random function or variable and build like an
> RSS feed of the results or something.  Because I don't know how many
> times I've been just randomly browsing around the documentation or
> source and found something like c-subword-mode that I otherwise would
> not have known even existed!

Sounds like a good idea.

	Hannes

Re: A way to get a list of available functions / variables?

[Taylor Venable]

Johannes Weiner <hannes@saeurebad.de> writes:

>> Is there a way to programmatically get the list of available functions?
>> I'm thinking there must be a table somewhere which relates symbol names
>> to actual function definitions, but can you get all the names in the
>> table from Lisp code?  If so, my second question would then be if I
>> could do the same for variables.
>
> mapatoms might help:
>
> (let (cmds vars)
>   (mapatoms (lambda (atom)
> 	      (cond
> 	       ((commandp atom)
> 		(setq cmds (cons atom cmds)))
> 	       ((custom-variable-p atom)
> 		(setq vars (cons atom vars)))))))

That is very cool, thanks much!

>> The reason I ask is I've got this thing going on at my college where
>> I'll write up an Emacs "function of the day" on the whiteboard in the
>> computer science lounge.  It'd be cool if I could automate this process
>> to automatically choose a random function or variable and build like an
>> RSS feed of the results or something.  Because I don't know how many
>> times I've been just randomly browsing around the documentation or
>> source and found something like c-subword-mode that I otherwise would
>> not have known even existed!
>
> Sounds like a good idea.

Thanks; I'll post to emacs-help when I get it finished and working suitably.

-- 
Taylor Venable            http://real.metasyntax.net:2357/

foldr = lambda f, i, l: (len(l) == 1 and [f(l[0], i)] or
                         [f(l[0], foldr(f, i, l[1:]))])[0]

Re: A way to get a list of available functions / variables?

[Xavier Maillard]

   Thanks; I'll post to emacs-help when I get it finished and working suitably.

You'd rather want to post this into gnu-emacs-source instead
which is a "source code oriented mailing-list" for GNU Emacs.

	Xavier
-- 
http://www.gnu.org
http://www.april.org
http://www.lolica.org

Re: A way to get a list of available functions / variables?

[Davis Herring]

> (remove-if-not (lambda (atom)
> 		 (or (commandp atom)
> 		     (custom-variable-p atom)))
> 	       obarray)

Unless CL is a lot more clever than I think it is, this won't work: the
obarray is really a hash table with linked buckets, and Lisp can't see the
links.  (See (elisp)Creating symbols.)

Davis

PS - Sorry for the long delay in writing this.

-- 
This product is sold by volume, not by mass.  If it appears too dense or
too sparse, it is because mass-energy conversion has occurred during
shipping.

Re: A way to get a list of available functions / variables?

[David Kastrup]

"Davis Herring" <herring@lanl.gov> writes:

>> (remove-if-not (lambda (atom)
>> 		 (or (commandp atom)
>> 		     (custom-variable-p atom)))
>> 	       obarray)
>
> Unless CL is a lot more clever than I think it is, this won't work: the
> obarray is really a hash table with linked buckets, and Lisp can't see the
> links.  (See (elisp)Creating symbols.)

That's what mapatoms is for.

(let (l) (mapatoms (lambda (atom) (when (or (commandp atom)
  (custom-variable-p atom)) (push atom l)))) l)


-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum