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[emacs.git] / lisp / replace.el

;;; replace.el --- replace commands for Emacs.

;; Copyright (C) 1985, 86, 87, 88, 89, 90, 91, 92 Free Software Foundation, Inc.

;; Maintainer: FSF

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Code:

(defconst case-replace t "\
*Non-nil means query-replace should preserve case in replacements.")

(defun query-replace (from-string to-string &optional arg)
  "Replace some occurrences of FROM-STRING with TO-STRING.
As each match is found, the user must type a character saying
what to do with it.  For directions, type \\[help-command] at that time.

Preserves case in each replacement if  case-replace  and  case-fold-search
are non-nil and FROM-STRING has no uppercase letters.
Third arg DELIMITED (prefix arg if interactive) non-nil means replace
only matches surrounded by word boundaries."
  (interactive "sQuery replace: \nsQuery replace %s with: \nP")
  (perform-replace from-string to-string t nil arg)
  (message "Done"))
(define-key esc-map "%" 'query-replace)

(defun query-replace-regexp (regexp to-string &optional arg)
  "Replace some things after point matching REGEXP with TO-STRING.
As each match is found, the user must type a character saying
what to do with it.  For directions, type \\[help-command] at that time.

Preserves case in each replacement if  case-replace  and  case-fold-search
are non-nil and REGEXP has no uppercase letters.
Third arg DELIMITED (prefix arg if interactive) non-nil means replace
only matches surrounded by word boundaries.
In TO-STRING, \\& means insert what matched REGEXP,
and \\=\\<n> means insert what matched <n>th \\(...\\) in REGEXP."
  (interactive "sQuery replace regexp: \nsQuery replace regexp %s with: \nP")
  (perform-replace regexp to-string t t arg)
  (message "Done"))

(defun map-query-replace-regexp (regexp to-strings &optional arg)
  "Replace some matches for REGEXP with various strings, in rotation.
The second argument TO-STRINGS contains the replacement strings, separated
by spaces.  This command works like `query-replace-regexp' except
that each successive replacement uses the next successive replacement string,
wrapping around from the last such string to the first.

Non-interactively, TO-STRINGS may be a list of replacement strings.

A prefix argument N says to use each replacement string N times
before rotating to the next."
  (interactive "sMap query replace (regexp): \nsQuery replace %s with (space-separated strings): \nP")
  (let (replacements)
    (if (listp to-strings)
        (setq replacements to-strings)
      (while (/= (length to-strings) 0)
        (if (string-match " " to-strings)
            (setq replacements
                  (append replacements
                          (list (substring to-strings 0
                                           (string-match " " to-strings))))
                  to-strings (substring to-strings
                                       (1+ (string-match " " to-strings))))
          (setq replacements (append replacements (list to-strings))
                to-strings ""))))
    (perform-replace regexp replacements t t nil arg))
  (message "Done"))

(defun replace-string (from-string to-string &optional delimited)
  "Replace occurrences of FROM-STRING with TO-STRING.
Preserve case in each match if `case-replace' and `case-fold-search'
are non-nil and FROM-STRING has no uppercase letters.
Third arg DELIMITED (prefix arg if interactive) non-nil means replace
only matches surrounded by word boundaries.

This function is usually the wrong thing to use in a Lisp program.
What you probably want is a loop like this:
  (while (search-forward OLD-STRING nil t)
    (replace-match REPLACEMENT nil t))
which will run faster and will not set the mark or print anything."
  (interactive "sReplace string: \nsReplace string %s with: \nP")
  (perform-replace from-string to-string nil nil delimited)
  (message "Done"))

(defun replace-regexp (regexp to-string &optional delimited)
  "Replace things after point matching REGEXP with TO-STRING.
Preserve case in each match if case-replace and case-fold-search
are non-nil and REGEXP has no uppercase letters.
Third arg DELIMITED (prefix arg if interactive) non-nil means replace
only matches surrounded by word boundaries.
In TO-STRING, \\& means insert what matched REGEXP,
and \\=\\<n> means insert what matched <n>th \\(...\\) in REGEXP.

This function is usually the wrong thing to use in a Lisp program.
What you probably want is a loop like this:
  (while (re-search-forward REGEXP nil t)
    (replace-match REPLACEMENT nil nil))
which will run faster and will not set the mark or print anything."
  (interactive "sReplace regexp: \nsReplace regexp %s with: \nP")
  (perform-replace regexp to-string nil t delimited)
  (message "Done"))

(fset 'delete-non-matching-lines 'keep-lines)
(defun keep-lines (regexp)
  "Delete all lines except those containing matches for REGEXP.
A match split across lines preserves all the lines it lies in.
Applies to all lines after point."
  (interactive "sKeep lines (containing match for regexp): ")
  (save-excursion
    (or (bolp) (forward-line 1))
    (let ((start (point)))
      (while (not (eobp))
        ;; Start is first char not preserved by previous match.
        (if (not (re-search-forward regexp nil 'move))
            (delete-region start (point-max))
          (let ((end (save-excursion (goto-char (match-beginning 0))
                                     (beginning-of-line)
                                     (point))))
            ;; Now end is first char preserved by the new match.
            (if (< start end)
                (delete-region start end))))
        (setq start (save-excursion (forward-line 1)
                                    (point)))
        ;; If the match was empty, avoid matching again at same place.
        (and (not (eobp)) (= (match-beginning 0) (match-end 0))
             (forward-char 1))))))

(fset 'delete-matching-lines 'flush-lines)
(defun flush-lines (regexp)
  "Delete lines containing matches for REGEXP.
If a match is split across lines, all the lines it lies in are deleted.
Applies to lines after point."
  (interactive "sFlush lines (containing match for regexp): ")
  (save-excursion
    (while (and (not (eobp))
                (re-search-forward regexp nil t))
      (delete-region (save-excursion (goto-char (match-beginning 0))
                                     (beginning-of-line)
                                     (point))
                     (progn (forward-line 1) (point))))))

(fset 'count-matches 'how-many)
(defun how-many (regexp)
  "Print number of matches for REGEXP following point."
  (interactive "sHow many matches for (regexp): ")
  (let ((count 0) opoint)
    (save-excursion
     (while (and (not (eobp))
                 (progn (setq opoint (point))
                        (re-search-forward regexp nil t)))
       (if (= opoint (point))
           (forward-char 1)
         (setq count (1+ count))))
     (message "%d occurrences" count))))

(defvar occur-mode-map ())
(if occur-mode-map
    ()
  (setq occur-mode-map (make-sparse-keymap))
  (define-key occur-mode-map "\C-c\C-c" 'occur-mode-goto-occurrence))

(defvar occur-buffer nil)
(defvar occur-nlines nil)
(defvar occur-pos-list nil)
(defvar occur-last-string "")

(defun occur-mode ()
  "Major mode for output from \\[occur].
Move point to one of the occurrences in this buffer,
then use \\[occur-mode-goto-occurrence] to go to the same occurrence
in the buffer that the occurrences were found in.
\\{occur-mode-map}"
  (kill-all-local-variables)
  (use-local-map occur-mode-map)
  (setq major-mode 'occur-mode)
  (setq mode-name "Occur")
  (make-local-variable 'occur-buffer)
  (make-local-variable 'occur-nlines)
  (make-local-variable 'occur-pos-list))

(defun occur-mode-goto-occurrence ()
  "Go to the line this occurrence was found in, in the buffer it was found in."
  (interactive)
  (if (or (null occur-buffer)
          (null (buffer-name occur-buffer)))
      (progn
        (setq occur-buffer nil
              occur-pos-list nil)
        (error "Buffer in which occurrences were found is deleted")))
  (let* ((occur-number (save-excursion
                         (beginning-of-line)
                         (/ (1- (count-lines (point-min)
                                             (save-excursion
                                               (beginning-of-line)
                                               (point))))
                            (cond ((< occur-nlines 0)
                                   (- 2 occur-nlines))
                                  ((> occur-nlines 0)
                                   (+ 2 (* 2 occur-nlines)))
                                  (t 1)))))
         (pos (nth occur-number occur-pos-list)))
    (pop-to-buffer occur-buffer)
    (goto-char (marker-position pos))))

(defvar list-matching-lines-default-context-lines 0
  "*Default number of context lines to include around a `list-matching-lines'
match.  A negative number means to include that many lines before the match.
A positive number means to include that many lines both before and after.")

(defvar occur-whole-buffer nil
  "If t, occur operates on whole buffer, otherwise occur starts from point.
default is nil.")

(fset 'list-matching-lines 'occur)

(defun occur (regexp &optional nlines)
  "Show lines containing a match for REGEXP.  If the global variable
`occur-whole-buffer' is non-nil, the entire buffer is searched, otherwise
search begins at point.  Interactively, REGEXP defaults to the last REGEXP
used interactively with \\[occur].

If a match spreads across multiple lines, all those lines are shown.

Each line is displayed with NLINES lines before and after, or -NLINES
before if NLINES is negative.
NLINES defaults to `list-matching-lines-default-context-lines'.
Interactively it is the prefix arg.

The lines are shown in a buffer named *Occur*.
It serves as a menu to find any of the occurrences in this buffer.
\\[describe-mode] in that buffer will explain how."
  (interactive (list (setq occur-last-string
                           (read-string "List lines matching regexp: "
                                        occur-last-string))
                     current-prefix-arg))
  (setq nlines (if nlines (prefix-numeric-value nlines)
                 list-matching-lines-default-context-lines))
  (let ((first t)
        (buffer (current-buffer))
        (linenum 1)
        (prevpos (point-min))
        (final-context-start (make-marker)))
    (if (not occur-whole-buffer)
        (save-excursion
          (beginning-of-line)
          (setq linenum (1+ (count-lines (point-min) (point))))
          (setq prevpos (point))))
    (with-output-to-temp-buffer "*Occur*"
      (save-excursion
        (set-buffer standard-output)
        (insert "Lines matching ")
        (prin1 regexp)
        (insert " in buffer " (buffer-name buffer) ?. ?\n)
        (occur-mode)
        (setq occur-buffer buffer)
        (setq occur-nlines nlines)
        (setq occur-pos-list ()))
      (if (eq buffer standard-output)
          (goto-char (point-max)))
      (save-excursion
        (if occur-whole-buffer
            (beginning-of-buffer))
        ;; Find next match, but give up if prev match was at end of buffer.
        (while (and (not (= prevpos (point-max)))
                    (re-search-forward regexp nil t))
          (goto-char (match-beginning 0))
          (beginning-of-line)
          (setq linenum (+ linenum (count-lines prevpos (point))))
          (setq prevpos (point))
          (goto-char (match-end 0))
          (let* ((start (save-excursion
                          (goto-char (match-beginning 0))
                          (forward-line (if (< nlines 0) nlines (- nlines)))
                          (point)))
                 (end (save-excursion
                        (goto-char (match-end 0))
                        (if (> nlines 0)
                            (forward-line (1+ nlines))
                            (forward-line 1))
                        (point)))
                 (tag (format "%3d" linenum))
                 (empty (make-string (length tag) ?\ ))
                 tem)
            (save-excursion
              (setq tem (make-marker))
              (set-marker tem (point))
              (set-buffer standard-output)
              (setq occur-pos-list (cons tem occur-pos-list))
              (or first (zerop nlines)
                  (insert "--------\n"))
              (setq first nil)
              (insert-buffer-substring buffer start end)
              (backward-char (- end start))
              (setq tem nlines)
              (while (> tem 0)
                (insert empty ?:)
                (forward-line 1)
                (setq tem (1- tem)))
              (let ((this-linenum linenum))
                (set-marker final-context-start
                            (+ (point) (- (match-end 0) (match-beginning 0))))
                (while (< (point) final-context-start)
                  (if (null tag)
                      (setq tag (format "%3d" this-linenum)))
                  (insert tag ?:)
                  (setq tag nil)
                  (forward-line 1)
                  (setq this-linenum (1+ this-linenum))))
              (while (< tem nlines)
                (insert empty ?:)
                (forward-line 1)
                (setq tem (1+ tem))))                           
            (forward-line 1)))
        (set-buffer standard-output)
        ;; Put positions in increasing order to go with buffer.
        (setq occur-pos-list (nreverse occur-pos-list))
        (if (interactive-p)
            (message "%d matching lines." (length occur-pos-list)))))))
\f
(defconst query-replace-help
  "Type Space or `y' to replace one match, Delete or `n' to skip to next,
ESC or `q' to exit, Period to replace one match and exit,
Comma to replace but not move point immediately,
C-r to enter recursive edit (\\[exit-recursive-edit] to get out again),
C-w to delete match and recursive edit,
C-l to clear the screen, redisplay, and offer same replacement again,
! to replace all remaining matches with no more questions,
^ to move point back to previous match."
  "Help message while in query-replace")

(defun perform-replace (from-string replacements
                        query-flag regexp-flag delimited-flag
                        &optional repeat-count)
  "Subroutine of `query-replace'.  Its complexity handles interactive queries.
Don't use this in your own program unless you want to query and set the mark
just as `query-replace' does.  Instead, write a simple loop like this:
  (while (re-search-forward \"foo[ \t]+bar\" nil t)
    (replace-match \"foobar\" nil nil))
which will run faster and do exactly what you probably want."
  (let ((nocasify (not (and case-fold-search case-replace
                            (string-equal from-string
                                          (downcase from-string)))))
        (literal (not regexp-flag))
        (search-function (if regexp-flag 're-search-forward 'search-forward))
        (search-string from-string)
        (real-match-data nil)           ; the match data for the current match
        (next-replacement nil)
        (replacement-index 0)
        (keep-going t)
        (stack nil)
        (next-rotate-count 0)
        (replace-count 0)
        (lastrepl nil)                  ;Position after last match considered.
        (match-after t))
    (if (stringp replacements)
        (setq next-replacement replacements)
      (or repeat-count (setq repeat-count 1)))
    (if delimited-flag
        (setq search-function 're-search-forward
              search-string (concat "\\b"
                                    (if regexp-flag from-string
                                      (regexp-quote from-string))
                                    "\\b")))
    (push-mark)
    (undo-boundary)
    (while (and keep-going
                (not (eobp))
                (funcall search-function search-string nil t)
                ;; If the search string matches immediately after
                ;; the previous match, but it did not match there
                ;; before the replacement was done, ignore the match.
                (if (or (eq lastrepl (point))
                        (and regexp-flag
                             (eq lastrepl (match-beginning 0))
                             (not match-again)))
                    (if (eobp)
                        nil
                      ;; Don't replace the null string 
                      ;; right after end of previous replacement.
                      (forward-char 1)
                      (funcall search-function search-string nil t))
                  t))

      ;; Save the data associated with the real match.
      (setq real-match-data (match-data))

      ;; Before we make the replacement, decide whether the search string
      ;; can match again just after this match.
      (if regexp-flag
          (setq match-again (looking-at search-string)))
      ;; If time for a change, advance to next replacement string.
      (if (and (listp replacements)
               (= next-rotate-count replace-count))
          (progn
            (setq next-rotate-count
                  (+ next-rotate-count repeat-count))
            (setq next-replacement (nth replacement-index replacements))
            (setq replacement-index (% (1+ replacement-index) (length replacements)))))
      (if (not query-flag)
          (progn
            (store-match-data real-match-data)
            (replace-match next-replacement nocasify literal)
            (setq replace-count (1+ replace-count)))
        (undo-boundary)
        (let (done replaced)
          (while (not done)
            (let ((help-form
                   '(concat "Query replacing "
                            (if regexp-flag "regexp " "")
                            from-string " with " next-replacement ".\n\n"
                            (substitute-command-keys query-replace-help))))
              (setq char help-char)
              (while (or (not (numberp char)) (= char help-char))
                (message "Query replacing %s with %s: " from-string next-replacement)
                (setq char (read-event))
                (if (and (numberp char) (= char ??))
                    (setq unread-command-char help-char char help-char))))
            ;; Restore the match data while we process the command.
            (store-match-data real-match-data)
            (cond ((or (= char ?\e)
                       (= char ?q))
                   (setq keep-going nil)
                   (setq done t))
                  ((= char ?^)
                   (let ((elt (car stack)))
                     (goto-char (car elt))
                     (setq replaced (eq t (cdr elt)))
                     (or replaced
                         (store-match-data (cdr elt)))
                     (setq stack (cdr stack))))              
                  ((or (= char ?\ )
                       (= char ?y))
                   (or replaced
                       (replace-match next-replacement nocasify literal))
                   (setq done t replaced t))
                  ((= char ?\.)
                   (or replaced
                       (replace-match next-replacement nocasify literal))
                   (setq keep-going nil)
                   (setq done t replaced t))
                  ((= char ?\,)
                   (if (not replaced)
                       (progn
                         (replace-match next-replacement nocasify literal)
                         (setq replaced t))))
                  ((= char ?!)
                   (or replaced
                       (replace-match next-replacement nocasify literal))
                   (setq done t query-flag nil replaced t))
                  ((or (= char ?\177)
                       (= char ?n))
                   (setq done t))
                  ((= char ?\C-l)
                   (recenter nil))
                  ((= char ?\C-r)
                   (store-match-data
                    (prog1 (match-data)
                      (save-excursion (recursive-edit))))
                   ;; Before we make the replacement,
                   ;; decide whether the search string
                   ;; can match again just after this match.
                   (if regexp-flag
                       (setq match-again (looking-at search-string))))
                  ((= char ?\C-w)
                   (delete-region (match-beginning 0) (match-end 0))
                   (store-match-data
                    (prog1 (match-data)
                      (save-excursion (recursive-edit))))
                   (setq replaced t))
                  (t
                   (setq keep-going nil)
                   (setq unread-command-char char)
                   (setq done t))))
          ;; Record previous position for ^ when we move on.
          ;; Change markers to numbers in the match data
          ;; since lots of markers slow down editing.
          (setq stack
                (cons (cons (point)
                            (or replaced
                                (mapcar
                                 (function (lambda (elt)
                                             (and elt
                                                  (marker-position elt))))
                                 (match-data))))
                      stack))
          (if replaced (setq replace-count (1+ replace-count)))))
      (setq lastrepl (point)))
    (and keep-going stack)))
\f
(defun map-query-replace-regexp (regexp to-strings &optional arg)
  "Replace some matches for REGEXP with various strings, in rotation.
The second argument TO-STRINGS contains the replacement strings, separated
by spaces.  This command works like `query-replace-regexp' except
that each successive replacement uses the next successive replacement
string, wrapping around from the last such string to the first.

Non-interactively, TO-STRINGS may be a list of replacement strings.

A prefix argument N says to use each replacement string N times
before rotating to the next."
  (interactive "sMap query replace (regexp): \nsQuery replace %s with (space-separated strings): \nP")
  (let (replacements)
    (if (listp to-strings)
        (setq replacements to-strings)
      (while (/= (length to-strings) 0)
        (if (string-match " " to-strings)
            (setq replacements
                  (append replacements
                          (list (substring to-strings 0
                                           (string-match " " to-strings))))
                  to-strings (substring to-strings
                                       (1+ (string-match " " to-strings))))
          (setq replacements (append replacements (list to-strings))
                to-strings ""))))
    (perform-replace regexp replacements t t nil arg))
  (message "Done"))

;;; replace.el ends here