4.3BSD/usr/contrib/emacs/lisp/isearch.el
;; Incremental search
;; Copyright (C) 1985 Richard M. Stallman.
;; This file is part of GNU Emacs.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY. No author or distributor
;; accepts responsibility to anyone for the consequences of using it
;; or for whether it serves any particular purpose or works at all,
;; unless he says so in writing. Refer to the GNU Emacs General Public
;; License for full details.
;; Everyone is granted permission to copy, modify and redistribute
;; GNU Emacs, but only under the conditions described in the
;; GNU Emacs General Public License. A copy of this license is
;; supposed to have been given to you along with GNU Emacs so you
;; can know your rights and responsibilities. It should be in a
;; file named COPYING. Among other things, the copyright notice
;; and this notice must be preserved on all copies.
; in loaddefs.el
;(defvar search-last-string ""
; "Last string search for by a search command.
;This does not include direct calls to the primitive search functions,
;and does not include searches that are aborted.")
;
;(defconst search-repeat-char ?\C-s
; "Character to repeat incremental search forwards.")
;(defconst search-reverse-char ?\C-r
; "Character to repeat incremental search backwards.")
;(defconst search-exit-char ?\e
; "Character to exit incremental search.")
;(defconst search-delete-char ?\177
; "Character to delete from incremental search string.")
;(defconst search-quote-char ?\C-q
; "Character to quote special characters for incremental search.")
;(defconst search-yank-word-char ?\C-w
; "Character to pull next word from buffer into search string.")
;(defconst search-yank-line-char ?\C-y
; "Character to pull rest of line from buffer into search string.")
;(defconst search-exit-option t
; "Non-nil means random control characters terminate incremental search.")
;
;(defvar isearch-slow-window-lines 1
; "*Number of lines in slow search display windows.")
;(defconst isearch-slow-speed 1200
; "*Highest terminal speed at which to use \"slow\" style incremental search.
;This is the style where a one-line window is created to show the line
;that the search has reached.")
;; This function does all the work of incremental search.
;; The functions attached to ^R and ^S are trivial,
;; merely calling this one, but they are always loaded by default
;; whereas this file can optionally be autoloadable.
;; This is the only entry point in this file.
(defun isearch (forward &optional regexp)
(let ((search-string "")
(search-message "")
(cmds nil)
(success t)
(invalid-regexp nil)
(slow-terminal-mode (<= (baud-rate) isearch-slow-speed))
(other-end nil) ;Start of last match if fwd, end if backwd.
(small-window nil) ;if t, using a small window
(window-min-height (min window-min-height (1+ isearch-slow-window-lines)))
;so we can make small windows
(found-point nil) ;to restore point from a small window
;; This is the window-start value found by the search.
(found-start nil)
(opoint (point))
(inhibit-quit t)) ;Prevent ^G from quitting immediately.
(isearch-push-state)
(save-window-excursion
(catch 'search-done
(while t
(or (>= unread-command-char 0)
(progn
(or (input-pending-p)
(isearch-message))
(if (and slow-terminal-mode
(not (or small-window (pos-visible-in-window-p))))
(progn
(setq small-window t)
(setq found-point (point))
(move-to-window-line 0)
(split-window nil (- (window-height)
(1+ isearch-slow-window-lines)))
(other-window 1)
(goto-char found-point)))))
(let ((char (if quit-flag
?\C-g
(read-char))))
(setq quit-flag nil
invalid-regexp nil)
;; Meta character means exit search.
(cond ((and (>= char 128)
search-exit-option)
(setq unread-command-char char)
(throw 'search-done t))
((eq char search-exit-char)
;; Esc means exit search normally.
;; Except, if first thing typed, it means do nonincremental
(if (= 0 (length search-string))
(nonincremental-search forward regexp))
(throw 'search-done t))
((= char ?\C-g)
;; ^G means the user tried to quit.
(ding)
(discard-input)
(if success
;; If search is successful, move back to starting point
;; and really do quit.
(progn (goto-char opoint)
(signal 'quit nil))
;; If search is failing, rub out until it is once more
;; successful.
(while (not success) (isearch-pop))))
((eq char search-repeat-char)
;; ^S means search again, forward, for the same string.
(setq forward t)
(if (null (cdr cmds))
;; If the first char typed,
;; it means search for the string of the previous search
(progn
(setq search-string search-last-string
search-message
(mapconcat 'text-char-description
search-string ""))))
(isearch-search)
(isearch-push-state))
((eq char search-reverse-char)
;; ^R is similar but it searches backward.
(setq forward nil)
(if (null (cdr cmds))
(progn
(setq search-string search-last-string
search-message
(mapconcat 'text-char-description
search-string ""))))
(isearch-search)
(isearch-push-state))
((= char search-delete-char)
;; Rubout means discard last input item and move point
;; back. If buffer is empty, just beep.
(if (null (cdr cmds))
(ding)
(isearch-pop)))
(t
(cond ((or (eq char search-yank-word-char)
(eq char search-yank-line-char))
;; ^W means gobble next word from buffer.
;; ^Y means gobble rest of line from buffer.
(let ((word (save-excursion
(and (not forward) other-end
(goto-char other-end))
(buffer-substring
(point)
(save-excursion
(if (eq char search-yank-line-char)
(end-of-line)
(forward-word 1))
(point))))))
(setq search-string (concat search-string word)
search-message
(concat search-message
(mapconcat 'text-char-description
word "")))))
;; Any other control char =>
;; unread it and exit the search normally.
((and search-exit-option
(/= char search-quote-char)
(< char ? ) (/= char ?\t) (/= char ?\r))
(setq unread-command-char char)
(throw 'search-done t))
(t
;; Any other character => add it to the
;; search string and search.
(cond ((= char search-quote-char)
(setq char (read-quoted-char
(isearch-message t))))
((= char ?\r)
;; unix braindeath
(setq char ?\n)))
(setq search-string (concat search-string
(char-to-string char))
search-message (concat search-message
(text-char-description char)))))
(if (and (not success)
;; unsuccessful regexp search may become
;; successful by addition of characters which
;; make search-string valid
(not regexp))
nil
(if other-end
(goto-char (if forward other-end
(min opoint (1+ other-end)))))
(isearch-search))
(isearch-push-state))))))
(setq found-start (window-start (selected-window)))
(setq found-point (point)))
(setq search-last-string search-string)
;; If there was movement, mark the starting position.
;; Maybe should test difference between and set mark iff > threshold.
(if (/= (point) opoint) (push-mark opoint))
(if small-window
(goto-char found-point)
;; Exiting the save-window-excursion clobbers this; restore it.
(set-window-start (selected-window) found-start t))
(message "")))
(defun isearch-message (&optional c-q-hack ing)
(or success (setq ing nil))
(let ((m (concat (if success "" "Failing ")
(if regexp (if success "Regexp " "regexp ") "")
"I-search"
(if forward ": " " backward: ")
search-message
(if c-q-hack "^Q" "")
(if invalid-regexp
(concat " [" invalid-regexp "]")
(if (and ing (not slow-terminal-mode)) " ..." "")))))
(if c-q-hack m (message "%s" m))))
(defun isearch-pop ()
(setq cmds (cdr cmds))
(let ((cmd (car cmds)))
(setq search-string (car cmd)
search-message (car (cdr cmd))
success (car (cdr (cdr (cdr cmd))))
forward (car (cdr (cdr (cdr (cdr cmd)))))
other-end (car (cdr (cdr (cdr (cdr (cdr cmd))))))
invalid-regexp (car (cdr (cdr (cdr (cdr (cdr (cdr cmd))))))))
(goto-char (car (cdr (cdr cmd))))))
(defun isearch-push-state ()
(setq cmds (cons (list search-string search-message (point)
success forward other-end invalid-regexp)
cmds)))
(defun isearch-search ()
(isearch-message nil t)
(if (setq success
(condition-case lossage
(let ((inhibit-quit nil))
(if regexp (setq invalid-regexp nil))
(funcall
(if regexp
(if forward 're-search-forward 're-search-backward)
(if forward 'search-forward 'search-backward))
search-string nil t))
(quit (setq unread-command-char ?\C-g)
nil)
(invalid-regexp (setq invalid-regexp (car (cdr lossage)))
nil)))
(setq other-end
(if forward (match-beginning 0) (match-end 0)))
(or invalid-regexp
(not (car (cdr (cdr (cdr (car cmds)))))) ;unsuccusful last time
(ding))
(goto-char (car (cdr (cdr (car cmds)))))))
;; This is called from incremental-search
;; if the first input character is the exit character.
;; We store the search string in search-string
;; which has been bound already by incremental-search
;; so that, when we exit, it is copied into search-last-string.
(defun nonincremental-search (forward regexp)
(let (message char (inhibit-quit nil))
;; Prompt assuming not word search,
(setq message (if regexp
(if forward "Regexp search: "
"Regexp search backward: ")
(if forward "Search: " "Search backward: ")))
(message "%s" message)
;; Read 1 char and switch to word search if it is ^W.
(setq char (read-char))
(if (eq char search-yank-word-char)
(setq message (if forward "Word search: " "Word search backward: "))
;; Otherwise let that 1 char be part of the search string.
(setq unread-command-char char))
;; Read the search string with corrected prompt.
(setq search-string (read-string message))
;; Empty means use default.
(if (= 0 (length search-string))
(setq search-string search-last-string)
;; Set last search string now so it is set even if we fail.
(setq search-last-string search-string))
;; Go ahead and search.
(funcall (if (eq char search-yank-word-char)
(if forward 'word-search-forward 'word-search-backward)
(if regexp
(if forward 're-search-forward 're-search-backward)
(if forward 'search-forward 'search-backward)))
search-string)))