Quickly finding out a function or a variable you need?

Quickly finding out a function or a variable you need?

[Elena]

Hello,

while writing Emacs Lisp code, I often use `describe-function' and
`describe-variable' to search for functions and variables related to
the task at hand.

This commands, however - unlike `apropos' - require you to know the
first characters. This means you'll have an hard time, for instance,
finding `kill-buffer' when looking for functions which operate on
buffers. Moreover, in both `describe-*', completion buffer is lost as
soon as you choose a completion, thus if you want to check another
interesting function/variable you just saw, you have to start all over
again.

I know I must be missing something... Maybe there is some super-search
facility inside Emacs which I don't know about (besides using Internet
search engines I mean)? How do you quickly find out a function or a
variable you need in your code, instead?

Thanks for sharing.

Re: Quickly finding out a function or a variable you need?

[Elena]

Damn! Just discovered that `apropos' looks for both functions and
variables. I've always been using it just for commands.

Sorry for asking.

Re: Quickly finding out a function or a variable you need?

[Pascal J. Bourguignon]

Elena <egarrulo@gmail.com> writes:

> Hello,
>
> while writing Emacs Lisp code, I often use `describe-function' and
> `describe-variable' to search for functions and variables related to
> the task at hand.
>
> This commands, however - unlike `apropos' - require you to know the
> first characters. 

Not anymore.  Starting from version 23, emacs can complete on the other
words too.  Just type:  M-x describe-function RET -buffer TAB

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/

Re: Quickly finding out a function or a variable you need?

[Elena]

On 6 Ago, 17:34, p...@informatimago.com (Pascal J. Bourguignon) wrote:
> For commands, you'd use M-x apropos-command RET

Which is bound to "C-h a". I got confused because I thought that every
help command was bound to a key, but this is not the case for
`apropos' and other `apropos-*' commands.

Re: Quickly finding out a function or a variable you need?

[Tim X]

Elena <egarrulo@gmail.com> writes:

> Hello,
>
> while writing Emacs Lisp code, I often use `describe-function' and
> `describe-variable' to search for functions and variables related to
> the task at hand.
>
> This commands, however - unlike `apropos' - require you to know the
> first characters. This means you'll have an hard time, for instance,
> finding `kill-buffer' when looking for functions which operate on
> buffers. Moreover, in both `describe-*', completion buffer is lost as
> soon as you choose a completion, thus if you want to check another
> interesting function/variable you just saw, you have to start all over
> again.
>
> I know I must be missing something... Maybe there is some super-search
> facility inside Emacs which I don't know about (besides using Internet
> search engines I mean)? How do you quickly find out a function or a
> variable you need in your code, instead?
>

I find that in addition to the apropos set of commands and the describe
facilities, that the elisp manual is extremely useful. Normally, I open
a frame with info running on the elisp manual. When looking for
something which I suspect is there, but have no idea what its name is, I
jump to the manual. Using either the menus, which are group into fairly
high level topics, such as buffers, strings, regexp, etc a quick read of
one of the relevant subsedtions usually gives me what I want fairly
quickly. The search facilities of info are also  very useful and then of
course their is the indexes. This combination seems to work pretty well.

Tim


-- 
tcross (at) rapttech dot com dot au

Re: Quickly finding out a function or a variable you need?

[Stefan Monnier]

> while writing Emacs Lisp code, I often use `describe-function' and
> `describe-variable' to search for functions and variables related to
> the task at hand.
> This commands, however - unlike `apropos' - require you to know the
> first characters. This means you'll have an hard time, for instance,
> finding `kill-buffer' when looking for functions which operate on
> buffers.

While these are clearly not the end-all-be-all of documentation, the
particular problem above is somewhat addressed in Emacs-23 by the new
completion facility where * is understand as a glob-character.  I.e.
C-h f *buffer TAB will list all functions that contain "buffer" in
their name.  Sadly, these are probably too many if you're looking for
kill-buffer.


        Stefan