Re: Add M-x occur to the menu-bar

[Ted Zlatanov <tzz@lifelogs.com>]

On Sat, 14 Feb 2004, rms@gnu.org wrote:

> In making a change of this kind,
> think the most important question is:
> 
>   what is the criterion for deciding which buffer to use?
> 
> What does the current proposed patch do?

Note I'm discussing the updated version of this patch, which I will
post to emacs-devel shortly (in both a unified and a context diff
version).

I follow the behavior of compile.el, which is:

- is the current buffer usable?  if yes, use it

- else, if we were given a usable buffer, use that

- else, look through all the buffer for a usable buffer

- else, throw an error

Now, the major difference is that I no longer use
compilation-buffer-p, which also tests if a buffer is a
compilation-mode buffer:

;;; test if a buffer is a compilation buffer
(defsubst compilation-buffer-p (buffer)
  "Test if BUFFER is a compilation buffer."
  (with-current-buffer buffer
    (or compilation-shell-minor-mode
	compilation-minor-mode
	(eq major-mode 'compilation-mode)
	compilation-next-error-function)))

I now use just next-error-buffer-p:

(defsubst next-error-buffer-p (buffer)
  "Test if BUFFER is a next-error capable buffer."
  (with-current-buffer buffer
    next-error-function))

Which will work properly with compile.el (because compile-internal
sets next-error-function), with grep.el (because it uses
compile-internal), and with any other modes that set and support
next-error-function (such as occur, as noted in the modified
replace.el).  So backwards compatibility is guaranteed.

I'll mention my other modifications in the post with the patch.

Ted