Re: collect-string (was: simple useful functions)

[Tak Ota]

And here is the change log update.

2010-11-04  Takaaki Ota  <address@hidden>

        * replace.el (occur-1): Add string collection feature when NLINES
        is zero or negative integer value.

-Tak

Thu, 04 Nov 2010 13:18:20 -0700: Tak Ota <address@hidden> wrote:

> The documentation can be something like this.  I just added the last
> paragraph below.
> 
> -Tak
> 
> `M-x occur'
>      Prompt for a regexp, and display a list showing each line in the
>      buffer that contains a match for it.  To limit the search to part
>      of the buffer, narrow to that part (*note Narrowing::).  A numeric
>      argument N specifies that N lines of context are to be displayed
>      before and after each matching line.  Currently, `occur' can not
>      correctly handle multiline matches.
> 
>      The buffer `*Occur*' containing the output serves as a menu for
>      finding the occurrences in their original context.  Click
>      `Mouse-2' on an occurrence listed in `*Occur*', or position point
>      there and type <RET>; this switches to the buffer that was
>      searched and moves point to the original of the chosen occurrence.
>      `o' and `C-o' display the match in another window; `C-o' does not
>      select it.
> 
>      After using `M-x occur', you can use `next-error' to visit the
>      occurrences found, one by one.  *note Compilation Mode::.
> 
>      When the numeric argument N is 0 or negative the buffer `*Occur*'
>      collects all the matched strings.  When N is 0 the entire text
>      matched is collected.  When N is negative the text in the -Nth
>      parenthesized expression in the regexp is collected.
> 
> 
> Thu, 04 Nov 2010 11:36:54 -0700: Tak Ota <address@hidden> wrote:
> 
> > Thu, 4 Nov 2010 06:58:20 -0700: Stefan Monnier <address@hidden> wrote:
> > 
> > > >> How about rename the command as collect-occur instead of
> > > >> collect-string and document it as next?
> > > > Wrong namespace.  IMO, the name should *start* with occur (but Stefan
> > > > and Yidong are final authorities on that).
> > > 
> > > Agreed, namespace cleanliness is one of my favorite forms of
> > > anal retentiveness.
> > > 
> > > The way I see it, the suggested collect-string is a variant of occur
> > > where the result buffer contains none of the regexp matches's context.
> > > So it would make sense to integrate it very tightly with `occur',
> > > i.e. make M-x occur do the job of collect-strings for some particular
> > > value of its argument NLINES.  Currently, NLINES is assumed to be
> > > a number and all values of that number have a useful meaning, so we'd
> > > have to add this new feature via a non-number value of NLINES.
> > > 
> > > E.g. C-u M-x occur could do the collect-string thingy (which is still an
> > > incompatible change since some people may like to use C-u M-x occur to get
> > > 4 lines of context, but you can make omelets without breaking eggs).
> > > 
> > > 
> > >         Stefan
> > > 
> > 
> > Now I am convinced.  How about the change below?  In conventional
> > occur zero or negative value for nlines is meaningless correct?  We
> > can use that for collection purpose.  i.e. C-u 0 M-x occur does the
> > collection of the matching pattern.  C-u -1 M-x occur performs the
> > collection of the recorded pattern 1.
> > 
> > -Tak
> > 
> > (defun occur-1 (regexp nlines bufs &optional buf-name)
> >   (unless (and regexp (not (equal regexp "")))
> >     (error "Occur doesn't work with the empty regexp"))
> >   (unless buf-name
> >     (setq buf-name "*Occur*"))
> >   (let (occur-buf
> >     (active-bufs (delq nil (mapcar #'(lambda (buf)
> >                                        (when (buffer-live-p buf) buf))
> >                                    bufs))))
> >     ;; Handle the case where one of the buffers we're searching is the
> >     ;; output buffer.  Just rename it.
> >     (when (member buf-name (mapcar 'buffer-name active-bufs))
> >       (with-current-buffer (get-buffer buf-name)
> >     (rename-uniquely)))
> > 
> >     ;; Now find or create the output buffer.
> >     ;; If we just renamed that buffer, we will make a new one here.
> >     (setq occur-buf (get-buffer-create buf-name))
> > 
> >     (if (or (null (integerp nlines))
> >         (> nlines 0))
> >     ;; nlines is not zero or negative so perform nomal occur
> >     (with-current-buffer occur-buf
> >       (occur-mode)
> >       (let ((inhibit-read-only t)
> >             ;; Don't generate undo entries for creation of the initial 
> > contents.
> >             (buffer-undo-list t))
> >         (erase-buffer)
> >         (let ((count (occur-engine
> >                       regexp active-bufs occur-buf
> >                       (or nlines list-matching-lines-default-context-lines)
> >                       (if (and case-fold-search search-upper-case)
> >                           (isearch-no-upper-case-p regexp t)
> >                         case-fold-search)
> >                       list-matching-lines-buffer-name-face
> >                       nil list-matching-lines-face
> >                       (not (eq occur-excluded-properties t)))))
> >           (let* ((bufcount (length active-bufs))
> >                  (diff (- (length bufs) bufcount)))
> >             (message "Searched %d buffer%s%s; %s match%s for `%s'"
> >                      bufcount (if (= bufcount 1) "" "s")
> >                      (if (zerop diff) "" (format " (%d killed)" diff))
> >                      (if (zerop count) "no" (format "%d" count))
> >                      (if (= count 1) "" "es")
> >                      regexp))
> >           (setq occur-revert-arguments (list regexp nlines bufs))
> >           (if (= count 0)
> >               (kill-buffer occur-buf)
> >             (display-buffer occur-buf)
> >             (setq next-error-last-buffer occur-buf)
> >             (setq buffer-read-only t)
> >             (set-buffer-modified-p nil)
> >             (run-hooks 'occur-hook)))))
> >       ;; nlines is zero or negative integer perform collect-string
> >       (with-current-buffer occur-buf
> >     (setq nlines (- nlines))
> >     (fundamental-mode)
> >     (let ((inhibit-read-only t)
> >           (buffer-undo-list t))
> >       (erase-buffer)
> >       (while active-bufs
> >         (with-current-buffer (car active-bufs)
> >           (save-excursion
> >             (goto-char (point-min))
> >             (while (re-search-forward regexp nil t)
> >               (let ((str (match-string nlines)))
> >                 (if str
> >                     (with-current-buffer occur-buf
> >                       (insert str)
> >                       (or (zerop (current-column))
> >                           (insert "\n"))))))))
> >         (setq active-bufs (cdr active-bufs))))
> >     (display-buffer occur-buf)))))