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

[Ted Zlatanov]

On 07 Feb 2004, address@hidden wrote:

> I haven't thought a lot about it, but I don't understand why you
> need that extra allow-with-next-error-function arg to
> compilation-buffer-p and compilation-find-buffer.

I was trying to draw a distinction between "find a compilation
buffer" in compile.el and "find a buffer where next-error will
work."  I'll leave it without that distinction for now, and I
don't think it will make a difference (based on my understanding
of the code).

> Can you mention the commands where is that behaviour NOT desireable,
> and why?

I was trying to preserve the *meaning* of compilation-find-buffer,
by making it select an Occur buffer only if specifically
requested.

> For the last four lines, you can just write
> 
>         (and allow-with-next-error-function
>              compilation-next-error-function)
> 
> as you already did a (set-buffer buffer), so there's no reason to
> use buffer-local-value here.

I originally had that code in replace.el, where I didn't want to
rely on the existence of the compilation-next-error-function
symbol.  My mistake.

> You no longer need the occur-last-buffer variable.

Done.

Attached is latest patch.  Thanks for your help.

Ted

--- 
/opt/local-csw/encap/emacs-cvs/share/emacs/21.3.50/lisp/progmodes/compile.el    
    Sat Jan  3 17:38:03 2004
+++ /home/tzz/emacs/mine/compile.el     Mon Feb  9 13:35:00 2004
@@ -36,7 +36,6 @@
   :group 'tools
   :group 'processes)
 
-
 ;;;###autoload
 (defcustom compilation-mode-hook nil
   "*List of hook functions run by `compilation-mode' (see `run-hooks')."
@@ -133,6 +132,15 @@
 A buffer becomes most recent when its compilation is started
 or when it is used with \\[next-error] or \\[compile-goto-error].")
 
+(defvar compilation-next-error-function nil
+  "The next-error analogue for other modes.
+This variable can be bound to a function by a mode.  It is
+buffer-local by default.  Together with
+`compilation-last-buffer', this variable lets modes hook into
+\\[next-error].")
+
+(make-variable-buffer-local 'compilation-next-error-function)
+
 (defvar compilation-in-progress nil
   "List of compilation processes now running.")
 (or (assq 'compilation-in-progress minor-mode-alist)
@@ -1057,10 +1065,12 @@
     errors))
 
 (defsubst compilation-buffer-p (buffer)
-  (save-excursion
-    (set-buffer buffer)
-    (or compilation-shell-minor-mode compilation-minor-mode
-       (eq major-mode 'compilation-mode))))
+  "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)))
 
 (defun compilation-next-error (n)
   "Move point to the next error in the compilation buffer.
@@ -1406,12 +1416,14 @@
 Just \\[universal-argument] as a prefix means reparse the error message buffer
 and start at the first error.
 
-\\[next-error] normally uses the most recently started compilation or
-grep buffer.  However, it can operate on any buffer with output from
-the \\[compile] and \\[grep] commands, or, more generally, on any
-buffer in Compilation mode or with Compilation Minor mode enabled.  To
-specify use of a particular buffer for error messages, type
-\\[next-error] in that buffer.
+\\[next-error] normally uses the most recently started
+compilation or grep buffer.  However, it can operate on any
+buffer with output from the \\[compile], \\[grep] commands, or,
+more generally, on any buffer in Compilation mode or with
+Compilation Minor mode enabled, or any buffer in which
+`compilation-next-error-function' is bound to an appropriate
+function.  To specify use of a particular buffer for error
+messages, type \\[next-error] in that buffer.
 
 Once \\[next-error] has chosen the buffer for error messages,
 it stays with that buffer until you use it in some other buffer which
@@ -1421,13 +1433,23 @@
 \`compilation-error-regexp-alist' for customization ideas."
   (interactive "P")
   (setq compilation-last-buffer (compilation-find-buffer))
-  (compilation-goto-locus (compilation-next-error-locus
-                          ;; We want to pass a number here only if
-                          ;; we got a numeric prefix arg, not just C-u.
-                          (and (not (consp argp))
-                               (prefix-numeric-value argp))
-                          (consp argp))))
+  (if (buffer-local-value 
+       'compilation-next-error-function 
+       compilation-last-buffer)
+      ;; do the right thing for modes that bind compilation-next-error-function
+      (progn
+       (set-buffer compilation-last-buffer)
+       (funcall compilation-next-error-function argp))
+    (compilation-goto-locus (compilation-next-error-locus
+                            ;; We want to pass a number here only if
+                            ;; we got a numeric prefix arg, not just C-u.
+                            (and (not (consp argp))
+                                 (prefix-numeric-value argp))
+                            (consp argp)))))
 ;;;###autoload (define-key ctl-x-map "`" 'next-error)
+
+(defalias 'goto-next-locus 'next-error)
+(defalias 'next-match 'next-error)
 
 (defun previous-error (argp)
   "Visit previous compilation error message and corresponding source code.

--- /opt/local-csw/encap/emacs-cvs/share/emacs/21.3.50/lisp/replace.el  Mon Feb 
 2 09:23:00 2004
+++ /home/tzz/emacs/mine/replace.el     Mon Feb  9 13:36:30 2004
@@ -614,6 +614,19 @@
   "Move to the Nth (default 1) previous match in an Occur mode buffer."
   (interactive "p")
   (occur-find-match n #'previous-single-property-change "No earlier matches"))
+
+(defun occur-next-error (&optional argp)
+  "Move to the Nth (default 1) next match in an Occur mode buffer.
+Compatibility function for \\[next-error] invocations."
+  (interactive "p")
+  (occur-find-match
+   (prefix-numeric-value argp)
+   (if (> 0 (prefix-numeric-value argp))
+       #'previous-single-property-change
+     #'next-single-property-change)
+   "No more matches")
+  (occur-mode-goto-occurrence))
+
 
 (defcustom list-matching-lines-default-context-lines 0
   "*Default number of context lines included around `list-matching-lines' 
matches.
@@ -800,7 +813,10 @@
        (setq occur-revert-arguments (list regexp nlines bufs)
              buffer-read-only t)
        (if (> count 0)
-           (display-buffer occur-buf)
+           (progn
+             (display-buffer occur-buf)
+             (setq compilation-last-buffer occur-buf)
+             (setq compilation-next-error-function 'occur-next-error))
          (kill-buffer occur-buf)))
       (run-hooks 'occur-hook))))