lisp/emacs-lisp/lisp.el

   1 ;;; lisp.el --- Lisp editing commands for Emacs
   2
   3 ;; Copyright (C) 1985, 1986, 1994, 2000, 2001, 2002, 2003, 2004,
   4 ;;   2005, 2006, 2007 Free Software Foundation, Inc.
   5
   6 ;; Maintainer: FSF
   7 ;; Keywords: lisp, languages
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Lisp editing commands to go with Lisp major mode.  More-or-less
  29 ;; applicable in other modes too.
  30
  31 ;;; Code:
  32
  33 ;; Note that this variable is used by non-lisp modes too.
  34 (defcustom defun-prompt-regexp nil
  35   "*If non-nil, a regexp to ignore before a defun.
  36 This is only necessary if the opening paren or brace is not in column 0.
  37 See function `beginning-of-defun'."
  38   :type '(choice (const nil)
  39                  regexp)
  40   :group 'lisp)
  41 (make-variable-buffer-local 'defun-prompt-regexp)
  42
  43 (defcustom parens-require-spaces t
  44   "If non-nil, `insert-parentheses' inserts whitespace as needed."
  45   :type 'boolean
  46   :group 'lisp)
  47
  48 (defvar forward-sexp-function nil
  49   "If non-nil, `forward-sexp' delegates to this function.
  50 Should take the same arguments and behave similarly to `forward-sexp'.")
  51
  52 (defun forward-sexp (&optional arg)
  53   "Move forward across one balanced expression (sexp).
  54 With ARG, do it that many times.  Negative arg -N means
  55 move backward across N balanced expressions."
  56   (interactive "p")
  57   (or arg (setq arg 1))
  58   (if forward-sexp-function
  59       (funcall forward-sexp-function arg)
  60     (goto-char (or (scan-sexps (point) arg) (buffer-end arg)))
  61     (if (< arg 0) (backward-prefix-chars))))
  62
  63 (defun backward-sexp (&optional arg)
  64   "Move backward across one balanced expression (sexp).
  65 With ARG, do it that many times.  Negative arg -N means
  66 move forward across N balanced expressions."
  67   (interactive "p")
  68   (or arg (setq arg 1))
  69   (forward-sexp (- arg)))
  70
  71 (defun mark-sexp (&optional arg allow-extend)
  72   "Set mark ARG sexps from point.
  73 The place mark goes is the same place \\[forward-sexp] would
  74 move to with the same argument.
  75 Interactively, if this command is repeated
  76 or (in Transient Mark mode) if the mark is active,
  77 it marks the next ARG sexps after the ones already marked."
  78   (interactive "P\np")
  79   (cond ((and allow-extend
  80               (or (and (eq last-command this-command) (mark t))
  81                   (and transient-mark-mode mark-active)))
  82          (setq arg (if arg (prefix-numeric-value arg)
  83                      (if (< (mark) (point)) -1 1)))
  84          (set-mark
  85           (save-excursion
  86             (goto-char (mark))
  87             (forward-sexp arg)
  88             (point))))
  89         (t
  90          (push-mark
  91           (save-excursion
  92             (forward-sexp (prefix-numeric-value arg))
  93             (point))
  94           nil t))))
  95
  96 (defun forward-list (&optional arg)
  97   "Move forward across one balanced group of parentheses.
  98 With ARG, do it that many times.
  99 Negative arg -N means move backward across N groups of parentheses."
 100   (interactive "p")
 101   (or arg (setq arg 1))
 102   (goto-char (or (scan-lists (point) arg 0) (buffer-end arg))))
 103
 104 (defun backward-list (&optional arg)
 105   "Move backward across one balanced group of parentheses.
 106 With ARG, do it that many times.
 107 Negative arg -N means move forward across N groups of parentheses."
 108   (interactive "p")
 109   (or arg (setq arg 1))
 110   (forward-list (- arg)))
 111
 112 (defun down-list (&optional arg)
 113   "Move forward down one level of parentheses.
 114 With ARG, do this that many times.
 115 A negative argument means move backward but still go down a level."
 116   (interactive "p")
 117   (or arg (setq arg 1))
 118   (let ((inc (if (> arg 0) 1 -1)))
 119     (while (/= arg 0)
 120       (goto-char (or (scan-lists (point) inc -1) (buffer-end arg)))
 121       (setq arg (- arg inc)))))
 122
 123 (defun backward-up-list (&optional arg)
 124   "Move backward out of one level of parentheses.
 125 With ARG, do this that many times.
 126 A negative argument means move forward but still to a less deep spot."
 127   (interactive "p")
 128   (up-list (- (or arg 1))))
 129
 130 (defun up-list (&optional arg)
 131   "Move forward out of one level of parentheses.
 132 With ARG, do this that many times.
 133 A negative argument means move backward but still to a less deep spot."
 134   (interactive "p")
 135   (or arg (setq arg 1))
 136   (let ((inc (if (> arg 0) 1 -1)))
 137     (while (/= arg 0)
 138       (goto-char (or (scan-lists (point) inc 1) (buffer-end arg)))
 139       (setq arg (- arg inc)))))
 140
 141 (defun kill-sexp (&optional arg)
 142   "Kill the sexp (balanced expression) following point.
 143 With ARG, kill that many sexps after point.
 144 Negative arg -N means kill N sexps before point."
 145   (interactive "p")
 146   (let ((opoint (point)))
 147     (forward-sexp (or arg 1))
 148     (kill-region opoint (point))))
 149
 150 (defun backward-kill-sexp (&optional arg)
 151   "Kill the sexp (balanced expression) preceding point.
 152 With ARG, kill that many sexps before point.
 153 Negative arg -N means kill N sexps after point."
 154   (interactive "p")
 155   (kill-sexp (- (or arg 1))))
 156
 157 ;; After Zmacs:
 158 (defun kill-backward-up-list (&optional arg)
 159   "Kill the form containing the current sexp, leaving the sexp itself.
 160 A prefix argument ARG causes the relevant number of surrounding
 161 forms to be removed."
 162   (interactive "*p")
 163   (let ((current-sexp (thing-at-point 'sexp)))
 164     (if current-sexp
 165         (save-excursion
 166           (backward-up-list arg)
 167           (kill-sexp)
 168           (insert current-sexp))
 169       (error "Not at a sexp"))))
 170 \f
 171 (defvar beginning-of-defun-function nil
 172   "If non-nil, function for `beginning-of-defun-raw' to call.
 173 This is used to find the beginning of the defun instead of using the
 174 normal recipe (see `beginning-of-defun').  Major modes can define this
 175 if defining `defun-prompt-regexp' is not sufficient to handle the mode's
 176 needs.
 177
 178 The function (of no args) should go to the line on which the current
 179 defun starts, and return non-nil, or should return nil if it can't
 180 find the beginning.")
 181
 182 (defun beginning-of-defun (&optional arg)
 183   "Move backward to the beginning of a defun.
 184 With ARG, do it that many times.  Negative arg -N
 185 means move forward to Nth following beginning of defun.
 186 Returns t unless search stops due to beginning or end of buffer.
 187
 188 If variable `beginning-of-defun-function' is non-nil, its value
 189 is called as a function to find the defun's beginning.
 190
 191 Normally a defun is assumed to start where there is a char with
 192 open-parenthesis syntax at the beginning of a line.  If
 193 `defun-prompt-regexp' is non-nil, then a string which matches
 194 that regexp may precede the open-parenthesis, and point ends up
 195 at the beginning of the line.
 196
 197 If `defun-prompt-regexp' and `open-paren-in-column-0-is-defun-start'
 198 are both nil, the function instead finds an open-paren at the
 199 outermost level."
 200   (interactive "p")
 201   (or (not (eq this-command 'beginning-of-defun))
 202       (eq last-command 'beginning-of-defun)
 203       (and transient-mark-mode mark-active)
 204       (push-mark))
 205   (and (beginning-of-defun-raw arg)
 206        (progn (beginning-of-line) t)))
 207
 208 (defun beginning-of-defun-raw (&optional arg)
 209   "Move point to the character that starts a defun.
 210 This is identical to function `beginning-of-defun', except that point
 211 does not move to the beginning of the line when `defun-prompt-regexp'
 212 is non-nil.
 213
 214 If variable `beginning-of-defun-function' is non-nil, its value
 215 is called as a function to find the defun's beginning."
 216   (interactive "p")   ; change this to "P", maybe, if we ever come to pass ARG
 217                       ; to beginning-of-defun-function.
 218   (unless arg (setq arg 1))
 219   (cond
 220    (beginning-of-defun-function
 221     (if (> arg 0)
 222         (dotimes (i arg)
 223           (funcall beginning-of-defun-function))
 224       ;; Better not call end-of-defun-function directly, in case
 225       ;; it's not defined.
 226       (end-of-defun (- arg))))
 227
 228    ((or defun-prompt-regexp open-paren-in-column-0-is-defun-start)
 229     (and (< arg 0) (not (eobp)) (forward-char 1))
 230     (and (re-search-backward (if defun-prompt-regexp
 231                                  (concat (if open-paren-in-column-0-is-defun-start
 232                                              "^\\s(\\|" "")
 233                                          "\\(?:" defun-prompt-regexp "\\)\\s(")
 234                                "^\\s(")
 235                              nil 'move arg)
 236          (progn (goto-char (1- (match-end 0)))) t))
 237
 238    ;; If open-paren-in-column-0-is-defun-start and defun-prompt-regexp
 239    ;; are both nil, column 0 has no significance - so scan forward
 240    ;; from BOB to see how nested point is, then carry on from there.
 241    ;;
 242    ;; It is generally not a good idea to land up here, because the
 243    ;; call to scan-lists below can be extremely slow.  This is because
 244    ;; back_comment in syntax.c may have to scan from bob to find the
 245    ;; beginning of each comment.  Fixing this is not trivial -- cyd.
 246
 247    ((eq arg 0))
 248    (t
 249     (let ((floor (point-min))
 250           (ceiling (point-max))
 251           (arg-+ve (> arg 0)))
 252       (save-restriction
 253         (widen)
 254         (let ((ppss (let (syntax-begin-function
 255                           font-lock-beginning-of-syntax-function)
 256                       (syntax-ppss)))
 257               ;; position of least enclosing paren, or nil.
 258               encl-pos)
 259           ;; Back out of any comment/string, so that encl-pos will always
 260           ;; become nil if we're at top-level.
 261           (when (nth 8 ppss)
 262             (goto-char (nth 8 ppss))
 263             (setq ppss (syntax-ppss)))  ; should be fast, due to cache.
 264           (setq encl-pos (syntax-ppss-toplevel-pos ppss))
 265           (if encl-pos (goto-char encl-pos))
 266
 267           (and encl-pos arg-+ve (setq arg (1- arg)))
 268           (and (not encl-pos) (not arg-+ve) (not (looking-at "\\s("))
 269                (setq arg (1+ arg)))
 270
 271           (condition-case nil   ; to catch crazy parens.
 272               (progn
 273                 (goto-char (scan-lists (point) (- arg) 0))
 274                 (if arg-+ve
 275                     (if (>= (point) floor)
 276                         t
 277                       (goto-char floor)
 278                       nil)
 279                   ;; forward to next (, or trigger the c-c
 280                   (goto-char (1- (scan-lists (point) 1 -1)))
 281                   (if (<= (point) ceiling)
 282                       t
 283                     (goto-char ceiling)
 284                     nil)))
 285             (error
 286              (goto-char (if arg-+ve floor ceiling))
 287              nil))))))))
 288
 289 (defvar end-of-defun-function nil
 290   "If non-nil, function for function `end-of-defun' to call.
 291 This is used to find the end of the defun instead of using the normal
 292 recipe (see `end-of-defun').  Major modes can define this if the
 293 normal method is not appropriate.")
 294
 295 (defun buffer-end (arg)
 296   "Return the \"far end\" position of the buffer, in direction ARG.
 297 If ARG is positive, that's the end of the buffer.
 298 Otherwise, that's the beginning of the buffer."
 299   (if (> arg 0) (point-max) (point-min)))
 300
 301 (defun end-of-defun (&optional arg)
 302   "Move forward to next end of defun.
 303 With argument, do it that many times.
 304 Negative argument -N means move back to Nth preceding end of defun.
 305
 306 An end of a defun occurs right after the close-parenthesis that
 307 matches the open-parenthesis that starts a defun; see function
 308 `beginning-of-defun'.
 309
 310 If variable `end-of-defun-function' is non-nil, its value
 311 is called as a function to find the defun's end."
 312   (interactive "p")
 313   (or (not (eq this-command 'end-of-defun))
 314       (eq last-command 'end-of-defun)
 315       (and transient-mark-mode mark-active)
 316       (push-mark))
 317   (if (or (null arg) (= arg 0)) (setq arg 1))
 318   (if end-of-defun-function
 319       (if (> arg 0)
 320           (dotimes (i arg)
 321             (funcall end-of-defun-function))
 322         ;; Better not call beginning-of-defun-function
 323         ;; directly, in case it's not defined.
 324         (beginning-of-defun (- arg)))
 325     (let ((first t))
 326       (while (and (> arg 0) (< (point) (point-max)))
 327         (let ((pos (point)))
 328           (while (progn
 329                    (if (and first
 330                             (progn
 331                               (end-of-line 1)
 332                               (beginning-of-defun-raw 1)))
 333                        nil
 334                      (or (bobp) (forward-char -1))
 335                      (beginning-of-defun-raw -1))
 336                    (setq first nil)
 337                    (forward-list 1)
 338                    (skip-chars-forward " \t")
 339                    (if (looking-at "\\s<\\|\n")
 340                        (forward-line 1))
 341                    (<= (point) pos))))
 342         (setq arg (1- arg)))
 343       (while (< arg 0)
 344         (let ((pos (point)))
 345           (beginning-of-defun-raw 1)
 346           (forward-sexp 1)
 347           (forward-line 1)
 348           (if (>= (point) pos)
 349               (if (beginning-of-defun-raw 2)
 350                   (progn
 351                     (forward-list 1)
 352                     (skip-chars-forward " \t")
 353                     (if (looking-at "\\s<\\|\n")
 354                         (forward-line 1)))
 355                 (goto-char (point-min)))))
 356         (setq arg (1+ arg))))))
 357
 358 (defun mark-defun (&optional allow-extend)
 359   "Put mark at end of this defun, point at beginning.
 360 The defun marked is the one that contains point or follows point.
 361
 362 Interactively, if this command is repeated
 363 or (in Transient Mark mode) if the mark is active,
 364 it marks the next defun after the ones already marked."
 365   (interactive "p")
 366   (cond ((and allow-extend
 367               (or (and (eq last-command this-command) (mark t))
 368                   (and transient-mark-mode mark-active)))
 369          (set-mark
 370           (save-excursion
 371             (goto-char (mark))
 372             (end-of-defun)
 373             (point))))
 374         (t
 375          (let ((opoint (point))
 376                beg end)
 377            (push-mark opoint)
 378            ;; Try first in this order for the sake of languages with nested
 379            ;; functions where several can end at the same place as with
 380            ;; the offside rule, e.g. Python.
 381            (beginning-of-defun)
 382            (setq beg (point))
 383            (end-of-defun)
 384            (setq end (point))
 385            (while (looking-at "^\n")
 386              (forward-line 1))
 387            (if (> (point) opoint)
 388                (progn
 389                  ;; We got the right defun.
 390                  (push-mark beg nil t)
 391                  (goto-char end)
 392                  (exchange-point-and-mark))
 393              ;; beginning-of-defun moved back one defun
 394              ;; so we got the wrong one.
 395              (goto-char opoint)
 396              (end-of-defun)
 397              (push-mark (point) nil t)
 398              (beginning-of-defun))
 399            (re-search-backward "^\n" (- (point) 1) t)))))
 400
 401 (defun narrow-to-defun (&optional arg)
 402   "Make text outside current defun invisible.
 403 The defun visible is the one that contains point or follows point.
 404 Optional ARG is ignored."
 405   (interactive)
 406   (save-excursion
 407     (widen)
 408     (let ((opoint (point))
 409           beg end)
 410       ;; Try first in this order for the sake of languages with nested
 411       ;; functions where several can end at the same place as with
 412       ;; the offside rule, e.g. Python.
 413       (beginning-of-defun)
 414       (setq beg (point))
 415       (end-of-defun)
 416       (setq end (point))
 417       (while (looking-at "^\n")
 418         (forward-line 1))
 419       (unless (> (point) opoint)
 420         ;; beginning-of-defun moved back one defun
 421         ;; so we got the wrong one.
 422         (goto-char opoint)
 423         (end-of-defun)
 424         (setq end (point))
 425         (beginning-of-defun)
 426         (setq beg (point)))
 427       (goto-char end)
 428       (re-search-backward "^\n" (- (point) 1) t)
 429       (narrow-to-region beg end))))
 430
 431 (defvar insert-pair-alist
 432   '((?\( ?\)) (?\[ ?\]) (?\{ ?\}) (?\< ?\>) (?\" ?\") (?\' ?\') (?\` ?\'))
 433   "Alist of paired characters inserted by `insert-pair'.
 434 Each element looks like (OPEN-CHAR CLOSE-CHAR) or (COMMAND-CHAR
 435 OPEN-CHAR CLOSE-CHAR).  The characters OPEN-CHAR and CLOSE-CHAR
 436 of the pair whose key is equal to the last input character with
 437 or without modifiers, are inserted by `insert-pair'.")
 438
 439 (defun insert-pair (&optional arg open close)
 440   "Enclose following ARG sexps in a pair of OPEN and CLOSE characters.
 441 Leave point after the first character.
 442 A negative ARG encloses the preceding ARG sexps instead.
 443 No argument is equivalent to zero: just insert characters
 444 and leave point between.
 445 If `parens-require-spaces' is non-nil, this command also inserts a space
 446 before and after, depending on the surrounding characters.
 447 If region is active, insert enclosing characters at region boundaries.
 448
 449 If arguments OPEN and CLOSE are nil, the character pair is found
 450 from the variable `insert-pair-alist' according to the last input
 451 character with or without modifiers.  If no character pair is
 452 found in the variable `insert-pair-alist', then the last input
 453 character is inserted ARG times."
 454   (interactive "P")
 455   (if (not (and open close))
 456       (let ((pair (or (assq last-command-char insert-pair-alist)
 457                       (assq (event-basic-type last-command-event)
 458                             insert-pair-alist))))
 459         (if pair
 460             (if (nth 2 pair)
 461                 (setq open (nth 1 pair) close (nth 2 pair))
 462               (setq open (nth 0 pair) close (nth 1 pair))))))
 463   (if (and open close)
 464       (if (and transient-mark-mode mark-active)
 465           (progn
 466             (save-excursion (goto-char (region-end))       (insert close))
 467             (save-excursion (goto-char (region-beginning)) (insert open)))
 468         (if arg (setq arg (prefix-numeric-value arg))
 469           (setq arg 0))
 470         (cond ((> arg 0) (skip-chars-forward " \t"))
 471               ((< arg 0) (forward-sexp arg) (setq arg (- arg))))
 472         (and parens-require-spaces
 473              (not (bobp))
 474              (memq (char-syntax (preceding-char)) (list ?w ?_ (char-syntax close)))
 475              (insert " "))
 476         (insert open)
 477         (save-excursion
 478           (or (eq arg 0) (forward-sexp arg))
 479           (insert close)
 480           (and parens-require-spaces
 481                (not (eobp))
 482                (memq (char-syntax (following-char)) (list ?w ?_ (char-syntax open)))
 483                (insert " "))))
 484     (insert-char (event-basic-type last-command-event)
 485                  (prefix-numeric-value arg))))
 486
 487 (defun insert-parentheses (&optional arg)
 488   "Enclose following ARG sexps in parentheses.
 489 Leave point after open-paren.
 490 A negative ARG encloses the preceding ARG sexps instead.
 491 No argument is equivalent to zero: just insert `()' and leave point between.
 492 If `parens-require-spaces' is non-nil, this command also inserts a space
 493 before and after, depending on the surrounding characters.
 494 If region is active, insert enclosing characters at region boundaries."
 495   (interactive "P")
 496   (insert-pair arg ?\( ?\)))
 497
 498 (defun delete-pair ()
 499   "Delete a pair of characters enclosing the sexp that follows point."
 500   (interactive)
 501   (save-excursion (forward-sexp 1) (delete-char -1))
 502   (delete-char 1))
 503
 504 (defun raise-sexp (&optional arg)
 505   "Raise ARG sexps higher up the tree."
 506   (interactive "p")
 507   (let ((s (if (and transient-mark-mode mark-active)
 508                (buffer-substring (region-beginning) (region-end))
 509              (buffer-substring
 510               (point)
 511               (save-excursion (forward-sexp arg) (point))))))
 512     (backward-up-list 1)
 513     (delete-region (point) (save-excursion (forward-sexp 1) (point)))
 514     (save-excursion (insert s))))
 515
 516 (defun move-past-close-and-reindent ()
 517   "Move past next `)', delete indentation before it, then indent after it."
 518   (interactive)
 519   (up-list 1)
 520   (forward-char -1)
 521   (while (save-excursion                ; this is my contribution
 522            (let ((before-paren (point)))
 523              (back-to-indentation)
 524              (and (= (point) before-paren)
 525                   (progn
 526                     ;; Move to end of previous line.
 527                     (beginning-of-line)
 528                     (forward-char -1)
 529                     ;; Verify it doesn't end within a string or comment.
 530                     (let ((end (point))
 531                           state)
 532                       (beginning-of-line)
 533                       ;; Get state at start of line.
 534                       (setq state  (list 0 nil nil
 535                                          (null (calculate-lisp-indent))
 536                                          nil nil nil nil
 537                                          nil))
 538                       ;; Parse state across the line to get state at end.
 539                       (setq state (parse-partial-sexp (point) end nil nil
 540                                                       state))
 541                       ;; Check not in string or comment.
 542                       (and (not (elt state 3)) (not (elt state 4))))))))
 543     (delete-indentation))
 544   (forward-char 1)
 545   (newline-and-indent))
 546
 547 (defun check-parens ()                  ; lame name?
 548   "Check for unbalanced parentheses in the current buffer.
 549 More accurately, check the narrowed part of the buffer for unbalanced
 550 expressions (\"sexps\") in general.  This is done according to the
 551 current syntax table and will find unbalanced brackets or quotes as
 552 appropriate.  (See Info node `(emacs)Parentheses'.)  If imbalance is
 553 found, an error is signaled and point is left at the first unbalanced
 554 character."
 555   (interactive)
 556   (condition-case data
 557       ;; Buffer can't have more than (point-max) sexps.
 558       (scan-sexps (point-min) (point-max))
 559     (scan-error (goto-char (nth 2 data))
 560                 ;; Could print (nth 1 data), which is either
 561                 ;; "Containing expression ends prematurely" or
 562                 ;; "Unbalanced parentheses", but those may not be so
 563                 ;; accurate/helpful, e.g. quotes may actually be
 564                 ;; mismatched.
 565                 (error "Unmatched bracket or quote"))
 566     (error (cond ((eq 'scan-error (car data))
 567                   (goto-char (nth 2 data))
 568                   (error "Unmatched bracket or quote"))
 569                  (t (signal (car data) (cdr data)))))))
 570 \f
 571 (defun lisp-complete-symbol (&optional predicate)
 572   "Perform completion on Lisp symbol preceding point.
 573 Compare that symbol against the known Lisp symbols.
 574 If no characters can be completed, display a list of possible completions.
 575 Repeating the command at that point scrolls the list.
 576
 577 When called from a program, optional arg PREDICATE is a predicate
 578 determining which symbols are considered, e.g. `commandp'.
 579 If PREDICATE is nil, the context determines which symbols are
 580 considered.  If the symbol starts just after an open-parenthesis, only
 581 symbols with function definitions are considered.  Otherwise, all
 582 symbols with function definitions, values or properties are
 583 considered."
 584   (interactive)
 585   (let ((window (get-buffer-window "*Completions*" 0)))
 586     (if (and (eq last-command this-command)
 587              window (window-live-p window) (window-buffer window)
 588              (buffer-name (window-buffer window)))
 589         ;; If this command was repeated, and
 590         ;; there's a fresh completion window with a live buffer,
 591         ;; and this command is repeated, scroll that window.
 592         (with-current-buffer (window-buffer window)
 593           (if (pos-visible-in-window-p (point-max) window)
 594               (set-window-start window (point-min))
 595             (save-selected-window
 596               (select-window window)
 597               (scroll-up))))
 598
 599       ;; Do completion.
 600       (let* ((end (point))
 601              (beg (with-syntax-table emacs-lisp-mode-syntax-table
 602                     (save-excursion
 603                       (backward-sexp 1)
 604                       (while (= (char-syntax (following-char)) ?\')
 605                         (forward-char 1))
 606                       (point))))
 607              (pattern (buffer-substring-no-properties beg end))
 608              (predicate
 609               (or predicate
 610                   (save-excursion
 611                     (goto-char beg)
 612                     (if (not (eq (char-before) ?\())
 613                         (lambda (sym)   ;why not just nil ?   -sm
 614                           (or (boundp sym) (fboundp sym)
 615                               (symbol-plist sym)))
 616                       ;; Looks like a funcall position.  Let's double check.
 617                       (if (condition-case nil
 618                               (progn (up-list -2) (forward-char 1)
 619                                      (eq (char-after) ?\())
 620                             (error nil))
 621                           ;; If the first element of the parent list is an open
 622                           ;; parenthesis we are probably not in a funcall position.
 623                           ;; Maybe a `let' varlist or something.
 624                           nil
 625                         ;; Else, we assume that a function name is expected.
 626                         'fboundp)))))
 627              (completion (try-completion pattern obarray predicate)))
 628         (cond ((eq completion t))
 629               ((null completion)
 630                (message "Can't find completion for \"%s\"" pattern)
 631                (ding))
 632               ((not (string= pattern completion))
 633                (delete-region beg end)
 634                (insert completion)
 635                ;; Don't leave around a completions buffer that's out of date.
 636                (let ((win (get-buffer-window "*Completions*" 0)))
 637                  (if win (with-selected-window win (bury-buffer)))))
 638               (t
 639                (let ((minibuf-is-in-use
 640                       (eq (minibuffer-window) (selected-window))))
 641                  (unless minibuf-is-in-use
 642                    (message "Making completion list..."))
 643                  (let ((list (all-completions pattern obarray predicate)))
 644                    (setq list (sort list 'string<))
 645                    (or (eq predicate 'fboundp)
 646                        (let (new)
 647                          (while list
 648                            (setq new (cons (if (fboundp (intern (car list)))
 649                                                (list (car list) " <f>")
 650                                              (car list))
 651                                            new))
 652                            (setq list (cdr list)))
 653                          (setq list (nreverse new))))
 654                    (if (> (length list) 1)
 655                        (with-output-to-temp-buffer "*Completions*"
 656                          (display-completion-list list pattern))
 657                      ;; Don't leave around a completions buffer that's
 658                      ;; out of date.
 659                      (let ((win (get-buffer-window "*Completions*" 0)))
 660                        (if win (with-selected-window win (bury-buffer))))))
 661                  (unless minibuf-is-in-use
 662                    (message "Making completion list...%s" "done")))))))))
 663
 664 ;; arch-tag: aa7fa8a4-2e6f-4e9b-9cd9-fef06340e67e
 665 ;;; lisp.el ends here