minibuffer.el 74.7 KB
Newer Older
1 2 3 4 5 6 7 8
;;; minibuffer.el --- Minibuffer completion functions

;; Copyright (C) 2008  Free Software Foundation, Inc.

;; Author: Stefan Monnier <monnier@iro.umontreal.ca>

;; This file is part of GNU Emacs.

9
;; GNU Emacs is free software: you can redistribute it and/or modify
10 11 12 13
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

14
;; GNU Emacs is distributed in the hope that it will be useful,
15 16 17 18 19
;; 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
20
;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
21 22 23

;;; Commentary:

24 25 26 27 28 29 30
;; Names with "--" are for functions and variables that are meant to be for
;; internal use only.

;; Functional completion tables have an extended calling conventions:
;; - If completion-all-completions-with-base-size is set, then all-completions
;;   should return the base-size in the last cdr.
;; - The `action' can be (additionally to nil, t, and lambda) of the form
31 32
;;   (boundaries . SUFFIX) in which case it should return
;;   (boundaries START . END).  See `completion-boundaries'.
33 34 35 36 37 38
;;   Any other return value should be ignored (so we ignore values returned
;;   from completion tables that don't know about this new `action' form).
;;   See `completion-boundaries'.

;;; Bugs:

39 40 41
;; - completion-all-sorted-completions list all the completions, whereas
;;   it should only lists the ones that `try-completion' would consider.
;;   E.g.  it should honor completion-ignored-extensions.
42 43 44 45
;; - choose-completion can't automatically figure out the boundaries
;;   corresponding to the displayed completions.  `base-size' gives the left
;;   boundary, but not the righthand one.  So we need to add
;;   completion-extra-size (and also completion-no-auto-exit).
46

47 48
;;; Todo:

49
;; - make lisp-complete-symbol and sym-comp use it.
50
;; - add support for ** to pcm.
51
;; - Make read-file-name-predicate obsolete.
52 53
;; - Add vc-file-name-completion-table to read-file-name-internal.
;; - A feature like completing-help.el.
54
;; - make lisp/complete.el obsolete.
55
;; - Make the `hide-spaces' arg of all-completions obsolete?
56 57 58 59 60

;;; Code:

(eval-when-compile (require 'cl))

61 62 63 64 65
(defvar completion-all-completions-with-base-size nil
  "If non-nil, `all-completions' may return the base-size in the last cdr.
The base-size is the length of the prefix that is elided from each
element in the returned list of completions.  See `completion-base-size'.")

66 67
;;; Completion table manipulation

68
;; New completion-table operation.
69 70
(defun completion-boundaries (string table pred suffix)
  "Return the boundaries of the completions returned by TABLE for STRING.
71
STRING is the string on which completion will be performed.
72 73 74 75 76 77
SUFFIX is the string after point.
The result is of the form (START . END) where START is the position
in STRING of the beginning of the completion field and END is the position
in SUFFIX of the end of the completion field.
E.g. for simple completion tables, the result is always (0 . (length SUFFIX))
and for file names the result is the positions delimited by
78 79
the closest directory separators."
  (let ((boundaries (if (functionp table)
80
                        (funcall table string pred (cons 'boundaries suffix)))))
81 82 83
    (if (not (eq (car-safe boundaries) 'boundaries))
        (setq boundaries nil))
    (cons (or (cadr boundaries) 0)
84
          (or (cddr boundaries) (length suffix)))))
85

86 87 88 89
(defun completion--some (fun xs)
  "Apply FUN to each element of XS in turn.
Return the first non-nil returned value.
Like CL's `some'."
90 91
  (let ((firsterror nil)
        res)
92
    (while (and (not res) xs)
93 94 95 96 97
      (condition-case err
          (setq res (funcall fun (pop xs)))
        (error (unless firsterror (setq firsterror err)) nil)))
    (or res
        (if firsterror (signal (car firsterror) (cdr firsterror))))))
98

99 100 101 102 103 104
(defun complete-with-action (action table string pred)
  "Perform completion ACTION.
STRING is the string to complete.
TABLE is the completion table, which should not be a function.
PRED is a completion predicate.
ACTION can be one of nil, t or `lambda'."
105 106 107 108 109 110 111 112 113 114 115
  (cond
   ((functionp table) (funcall table string pred action))
   ((eq (car-safe action) 'boundaries)
    (cons 'boundaries (completion-boundaries string table pred (cdr action))))
   (t
    (funcall
     (cond
      ((null action) 'try-completion)
      ((eq action t) 'all-completions)
      (t 'test-completion))
     string table pred))))
116 117 118 119

(defun completion-table-dynamic (fun)
  "Use function FUN as a dynamic completion table.
FUN is called with one argument, the string for which completion is required,
120 121 122 123
and it should return an alist containing all the intended possible completions.
This alist may be a full list of possible completions so that FUN can ignore
the value of its argument.  If completion is performed in the minibuffer,
FUN will be called in the buffer from which the minibuffer was entered.
124

125
The result of the `completion-table-dynamic' form is a function
126
that can be used as the COLLECTION argument to `try-completion' and
127
`all-completions'.  See Info node `(elisp)Programmed Completion'."
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144
  (lexical-let ((fun fun))
    (lambda (string pred action)
      (with-current-buffer (let ((win (minibuffer-selected-window)))
                             (if (window-live-p win) (window-buffer win)
                               (current-buffer)))
        (complete-with-action action (funcall fun string) string pred)))))

(defmacro lazy-completion-table (var fun)
  "Initialize variable VAR as a lazy completion table.
If the completion table VAR is used for the first time (e.g., by passing VAR
as an argument to `try-completion'), the function FUN is called with no
arguments.  FUN must return the completion table that will be stored in VAR.
If completion is requested in the minibuffer, FUN will be called in the buffer
from which the minibuffer was entered.  The return value of
`lazy-completion-table' must be used to initialize the value of VAR.

You should give VAR a non-nil `risky-local-variable' property."
145
  (declare (debug (symbolp lambda-expr)))
146 147 148 149 150 151 152 153
  (let ((str (make-symbol "string")))
    `(completion-table-dynamic
      (lambda (,str)
        (when (functionp ,var)
          (setq ,var (,fun)))
        ,var))))

(defun completion-table-with-context (prefix table string pred action)
154
  ;; TODO: add `suffix' maybe?
155
  ;; Notice that `pred' may not be a function in some abusive cases.
156 157 158 159 160 161 162 163 164 165 166 167 168 169 170
  (when (functionp pred)
    (setq pred
          (lexical-let ((pred pred))
            ;; Predicates are called differently depending on the nature of
            ;; the completion table :-(
            (cond
             ((vectorp table)           ;Obarray.
              (lambda (sym) (funcall pred (concat prefix (symbol-name sym)))))
             ((hash-table-p table)
              (lambda (s v) (funcall pred (concat prefix s))))
             ((functionp table)
              (lambda (s) (funcall pred (concat prefix s))))
             (t                         ;Lists and alists.
              (lambda (s)
                (funcall pred (concat prefix (if (consp s) (car s) s)))))))))
171 172
  (if (eq (car-safe action) 'boundaries)
      (let* ((len (length prefix))
173 174
             (bound (completion-boundaries string table pred (cdr action))))
        (list* 'boundaries (+ (car bound) len) (cdr bound)))
175 176 177 178 179 180 181 182 183 184 185 186
    (let ((comp (complete-with-action action table string pred)))
      (cond
       ;; In case of try-completion, add the prefix.
       ((stringp comp) (concat prefix comp))
       ;; In case of non-empty all-completions,
       ;; add the prefix size to the base-size.
       ((consp comp)
        (let ((last (last comp)))
          (when completion-all-completions-with-base-size
            (setcdr last (+ (or (cdr last) 0) (length prefix))))
          comp))
       (t comp)))))
187 188

(defun completion-table-with-terminator (terminator table string pred action)
189 190 191
  (cond
   ((eq action nil)
    (let ((comp (try-completion string table pred)))
192 193 194
      (if (eq comp t)
          (concat string terminator)
        (if (and (stringp comp)
195
                 (eq (try-completion comp table pred) t))
196
            (concat comp terminator)
197
          comp))))
198 199 200 201 202 203 204 205 206 207 208 209
   ((eq action t)
    ;; FIXME: We generally want the `try' and `all' behaviors to be
    ;; consistent so pcm can merge the `all' output to get the `try' output,
    ;; but that sometimes clashes with the need for `all' output to look
    ;; good in *Completions*.
    ;; (let* ((all (all-completions string table pred))
    ;;        (last (last all))
    ;;        (base-size (cdr last)))
    ;;   (when all
    ;;     (setcdr all nil)
    ;;     (nconc (mapcar (lambda (s) (concat s terminator)) all) base-size)))
    (all-completions string table pred))
210 211 212 213 214 215 216
   ;; completion-table-with-terminator is always used for
   ;; "sub-completions" so it's only called if the terminator is missing,
   ;; in which case `test-completion' should return nil.
   ((eq action 'lambda) nil)))

(defun completion-table-with-predicate (table pred1 strict string pred2 action)
  "Make a completion table equivalent to TABLE but filtered through PRED1.
217
PRED1 is a function of one argument which returns non-nil if and only if the
218 219 220
argument is an element of TABLE which should be considered for completion.
STRING, PRED2, and ACTION are the usual arguments to completion tables,
as described in `try-completion', `all-completions', and `test-completion'.
221 222
If STRICT is t, the predicate always applies; if nil it only applies if
it does not reduce the set of possible completions to nothing.
223 224 225 226
Note: TABLE needs to be a proper completion table which obeys predicates."
  (cond
   ((and (not strict) (eq action 'lambda))
    ;; Ignore pred1 since it doesn't really have to apply anyway.
227
    (test-completion string table pred2))
228 229 230 231 232 233 234 235 236 237 238 239
   (t
    (or (complete-with-action action table string
                              (if (null pred2) pred1
                                (lexical-let ((pred1 pred2) (pred2 pred2))
                                  (lambda (x)
                                    ;; Call `pred1' first, so that `pred2'
                                    ;; really can't tell that `x' is in table.
                                    (if (funcall pred1 x) (funcall pred2 x))))))
        ;; If completion failed and we're not applying pred1 strictly, try
        ;; again without pred1.
        (and (not strict)
             (complete-with-action action table string pred2))))))
240

241 242 243
(defun completion-table-in-turn (&rest tables)
  "Create a completion table that tries each table in TABLES in turn."
  (lexical-let ((tables tables))
244
    (lambda (string pred action)
245 246 247 248
      (completion--some (lambda (table)
                          (complete-with-action action table string pred))
                        tables))))

249 250
;; (defmacro complete-in-turn (a b) `(completion-table-in-turn ,a ,b))
;; (defmacro dynamic-completion-table (fun) `(completion-table-dynamic ,fun))
251 252
(define-obsolete-function-alias
  'complete-in-turn 'completion-table-in-turn "23.1")
253 254
(define-obsolete-function-alias
  'dynamic-completion-table 'completion-table-dynamic "23.1")
255 256 257

;;; Minibuffer completion

258 259 260 261 262
(defgroup minibuffer nil
  "Controlling the behavior of the minibuffer."
  :link '(custom-manual "(emacs)Minibuffer")
  :group 'environment)

263 264 265 266 267 268 269 270
(defun minibuffer-message (message &rest args)
  "Temporarily display MESSAGE at the end of the minibuffer.
The text is displayed for `minibuffer-message-timeout' seconds,
or until the next input event arrives, whichever comes first.
Enclose MESSAGE in [...] if this is not yet the case.
If ARGS are provided, then pass MESSAGE through `format'."
  ;; Clear out any old echo-area message to make way for our new thing.
  (message nil)
271 272 273 274
  (setq message (if (and (null args) (string-match "\\[.+\\]" message))
                    ;; Make sure we can put-text-property.
                    (copy-sequence message)
                  (concat " [" message "]")))
275
  (when args (setq message (apply 'format message args)))
276
  (let ((ol (make-overlay (point-max) (point-max) nil t t))
277 278 279 280 281 282
	;; A quit during sit-for normally only interrupts the sit-for,
        ;; but since minibuffer-message is used at the end of a command,
        ;; at a time when the command has virtually finished already, a C-g
        ;; should really cause an abort-recursive-edit instead (i.e. as if
        ;; the C-g had been typed at top-level).  Binding inhibit-quit here
        ;; is an attempt to get that behavior.
283
	(inhibit-quit t))
284 285
    (unwind-protect
        (progn
286 287 288 289 290
          (unless (zerop (length message))
            ;; The current C cursor code doesn't know to use the overlay's
            ;; marker's stickiness to figure out whether to place the cursor
            ;; before or after the string, so let's spoon-feed it the pos.
            (put-text-property 0 1 'cursor t message))
291 292 293 294 295 296 297 298 299 300 301 302
          (overlay-put ol 'after-string message)
          (sit-for (or minibuffer-message-timeout 1000000)))
      (delete-overlay ol))))

(defun minibuffer-completion-contents ()
  "Return the user input in a minibuffer before point as a string.
That is what completion commands operate on."
  (buffer-substring (field-beginning) (point)))

(defun delete-minibuffer-contents ()
  "Delete all user input in a minibuffer.
If the current buffer is not a minibuffer, erase its entire contents."
303 304 305
  ;; We used to do `delete-field' here, but when file name shadowing
  ;; is on, the field doesn't cover the entire minibuffer contents.
  (delete-region (minibuffer-prompt-end) (point-max)))
306

307 308 309 310 311 312
(defcustom completion-auto-help t
  "Non-nil means automatically provide help for invalid completion input.
If the value is t the *Completion* buffer is displayed whenever completion
is requested but cannot be done.
If the value is `lazy', the *Completions* buffer is only displayed after
the second failed attempt to complete."
313
  :type '(choice (const nil) (const t) (const lazy))
314 315
  :group 'minibuffer)

316
(defvar completion-styles-alist
317 318 319
  '((basic completion-basic-try-completion completion-basic-all-completions)
    (emacs22 completion-emacs22-try-completion completion-emacs22-all-completions)
    (emacs21 completion-emacs21-try-completion completion-emacs21-all-completions)
320 321
    (partial-completion
     completion-pcm-try-completion completion-pcm-all-completions))
322 323
  "List of available completion styles.
Each element has the form (NAME TRY-COMPLETION ALL-COMPLETIONS)
324
where NAME is the name that should be used in `completion-styles',
325 326 327
TRY-COMPLETION is the function that does the completion, and
ALL-COMPLETIONS is the function that lists the completions.")

328
(defcustom completion-styles '(basic partial-completion)
329 330 331 332 333 334
  "List of completion styles to use."
  :type `(repeat (choice ,@(mapcar (lambda (x) (list 'const (car x)))
                                   completion-styles-alist)))
  :group 'minibuffer
  :version "23.1")

335 336 337 338 339 340 341 342
(defun completion-try-completion (string table pred point)
  "Try to complete STRING using completion table TABLE.
Only the elements of table that satisfy predicate PRED are considered.
POINT is the position of point within STRING.
The return value can be either nil to indicate that there is no completion,
t to indicate that STRING is the only possible completion,
or a pair (STRING . NEWPOINT) of the completed result string together with
a new position for point."
343 344 345 346
  ;; The property `completion-styles' indicates that this functional
  ;; completion-table claims to take care of completion styles itself.
  ;; [I.e. It will most likely call us back at some point. ]
  (if (and (symbolp table) (get table 'completion-styles))
347 348 349 350 351
      ;; Extended semantics for functional completion-tables:
      ;; They accept a 4th argument `point' and when called with action=nil
      ;; and this 4th argument (a position inside `string'), they should
      ;; return instead of a string a pair (STRING . NEWPOINT).
      (funcall table string pred nil point)
352
    (completion--some (lambda (style)
353
                        (funcall (nth 1 (assq style completion-styles-alist))
354
                                 string table pred point))
355 356
                      completion-styles)))

357 358 359 360
(defun completion-all-completions (string table pred point)
  "List the possible completions of STRING in completion table TABLE.
Only the elements of table that satisfy predicate PRED are considered.
POINT is the position of point within STRING.
361
The return value is a list of completions and may contain the base-size
362
in the last `cdr'."
363
  (let ((completion-all-completions-with-base-size t))
364 365 366
    ;; The property `completion-styles' indicates that this functional
    ;; completion-table claims to take care of completion styles itself.
    ;; [I.e. It will most likely call us back at some point. ]
367 368 369 370 371 372
    (if (and (symbolp table) (get table 'completion-styles))
        ;; Extended semantics for functional completion-tables:
        ;; They accept a 4th argument `point' and when called with action=t
        ;; and this 4th argument (a position inside `string'), they may
        ;; return BASE-SIZE in the last `cdr'.
        (funcall table string pred t point)
373
      (completion--some (lambda (style)
374
                          (funcall (nth 2 (assq style completion-styles-alist))
375
                                   string table pred point))
376 377
                        completion-styles))))

378 379 380 381 382
(defun minibuffer--bitset (modified completions exact)
  (logior (if modified    4 0)
          (if completions 2 0)
          (if exact       1 0)))

383
(defun completion--do-completion (&optional try-completion-function)
384
  "Do the completion and return a summary of what happened.
385 386 387 388 389 390 391 392 393 394 395 396 397 398
M = completion was performed, the text was Modified.
C = there were available Completions.
E = after completion we now have an Exact match.

 MCE
 000  0 no possible completion
 001  1 was already an exact and unique completion
 010  2 no completion happened
 011  3 was already an exact completion
 100  4 ??? impossible
 101  5 ??? impossible
 110  6 some completion happened
 111  7 completed to an exact completion"
  (let* ((beg (field-beginning))
399
         (end (field-end))
400
         (string (buffer-substring beg end))
401 402 403 404 405 406
         (comp (funcall (or try-completion-function
			    'completion-try-completion)
			string
			minibuffer-completion-table
			minibuffer-completion-predicate
			(- (point) beg))))
407
    (cond
408
     ((null comp)
409
      (ding) (minibuffer-message "No match") (minibuffer--bitset nil nil nil))
410
     ((eq t comp) (minibuffer--bitset nil nil t)) ;Exact and unique match.
411 412 413 414
     (t
      ;; `completed' should be t if some completion was done, which doesn't
      ;; include simply changing the case of the entered string.  However,
      ;; for appearance, the string is rewritten if the case changes.
415 416 417 418
      (let* ((comp-pos (cdr comp))
	     (completion (car comp))
	     (completed (not (eq t (compare-strings completion nil nil
						    string nil nil t))))
419 420
	     (unchanged (eq t (compare-strings completion nil nil
					       string nil nil nil))))
421
        (unless unchanged
422 423

          ;; Insert in minibuffer the chars we got.
424 425
          (goto-char end)
          (insert completion)
426 427 428
          (delete-region beg end))
	;; Move point.
	(goto-char (+ beg comp-pos))
429

430 431 432 433 434
        (if (not (or unchanged completed))
	   ;; The case of the string changed, but that's all.  We're not sure
	   ;; whether this is a unique completion or not, so try again using
	   ;; the real case (this shouldn't recurse again, because the next
	   ;; time try-completion will return either t or the exact string).
435
           (completion--do-completion try-completion-function)
436 437

          ;; It did find a match.  Do we match some possibility exactly now?
438
          (let ((exact (test-completion completion
439 440
					minibuffer-completion-table
					minibuffer-completion-predicate)))
441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456
            (unless completed
              ;; Show the completion table, if requested.
              (cond
               ((not exact)
                (if (case completion-auto-help
                      (lazy (eq this-command last-command))
                      (t completion-auto-help))
                    (minibuffer-completion-help)
                  (minibuffer-message "Next char not unique")))
               ;; If the last exact completion and this one were the same,
               ;; it means we've already given a "Complete but not unique"
               ;; message and the user's hit TAB again, so now we give him help.
               ((eq this-command last-command)
                (if completion-auto-help (minibuffer-completion-help)))))

            (minibuffer--bitset completed t exact))))))))
457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481

(defun minibuffer-complete ()
  "Complete the minibuffer contents as far as possible.
Return nil if there is no valid completion, else t.
If no characters can be completed, display a list of possible completions.
If you repeat this command after it displayed such a list,
scroll the window of possible completions."
  (interactive)
  ;; If the previous command was not this,
  ;; mark the completion buffer obsolete.
  (unless (eq this-command last-command)
    (setq minibuffer-scroll-window nil))

  (let ((window minibuffer-scroll-window))
    ;; If there's a fresh completion window with a live buffer,
    ;; and this command is repeated, scroll that window.
    (if (window-live-p window)
        (with-current-buffer (window-buffer window)
          (if (pos-visible-in-window-p (point-max) window)
	      ;; If end is in view, scroll up to the beginning.
	      (set-window-start window (point-min) nil)
	    ;; Else scroll down one screen.
	    (scroll-other-window))
	  nil)

482
      (case (completion--do-completion)
483 484 485 486 487 488 489 490
        (#b000 nil)
        (#b001 (goto-char (field-end))
               (minibuffer-message "Sole completion")
               t)
        (#b011 (goto-char (field-end))
               (minibuffer-message "Complete, but not unique")
               t)
        (t     t)))))
491

492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544
(defvar completion-all-sorted-completions nil)
(make-variable-buffer-local 'completion-all-sorted-completions)

(defun completion--flush-all-sorted-completions (&rest ignore)
  (setq completion-all-sorted-completions nil))

(defun completion-all-sorted-completions ()
  (or completion-all-sorted-completions
      (let* ((start (field-beginning))
             (end (field-end))
             (all (completion-all-completions (buffer-substring start end)
                                              minibuffer-completion-table
                                              minibuffer-completion-predicate
                                              (- (point) start)))
             (last (last all))
             (base-size (or (cdr last) 0)))
        (when last
          (setcdr last nil)
          ;; Prefer shorter completions.
          (setq all (sort all (lambda (c1 c2) (< (length c1) (length c2)))))
          ;; Prefer recently used completions.
          (let ((hist (symbol-value minibuffer-history-variable)))
            (setq all (sort all (lambda (c1 c2)
                                  (> (length (member c1 hist))
                                     (length (member c2 hist)))))))
          ;; Cache the result.  This is not just for speed, but also so that
          ;; repeated calls to minibuffer-force-complete can cycle through
          ;; all possibilities.
          (add-hook 'after-change-functions
                    'completion--flush-all-sorted-completions nil t)
          (setq completion-all-sorted-completions
                (nconc all base-size))))))

(defun minibuffer-force-complete ()
  "Complete the minibuffer to an exact match.
Repeated uses step through the possible completions."
  (interactive)
  ;; FIXME: Need to deal with the extra-size issue here as well.
  (let* ((start (field-beginning))
         (end (field-end))
         (all (completion-all-sorted-completions)))
    (if (not (consp all))
        (minibuffer-message (if all "No more completions" "No completions"))
      (goto-char end)
      (insert (car all))
      (delete-region (+ start (cdr (last all))) end)
      ;; If completing file names, (car all) may be a directory, so we'd now
      ;; have a new set of possible completions and might want to reset
      ;; completion-all-sorted-completions to nil, but we prefer not to,
      ;; so that repeated calls minibuffer-force-complete still cycle
      ;; through the previous possible completions.
      (setq completion-all-sorted-completions (cdr all)))))

545
(defvar minibuffer-confirm-exit-commands
546
  '(minibuffer-complete minibuffer-complete-word PC-complete PC-complete-word)
547 548 549
  "A list of commands which cause an immediately following
`minibuffer-complete-and-exit' to ask for extra confirmation.")

550
(defun minibuffer-complete-and-exit ()
551 552 553 554 555 556 557 558 559 560 561 562
  "Exit if the minibuffer contains a valid completion.
Otherwise, try to complete the minibuffer contents.  If
completion leads to a valid completion, a repetition of this
command will exit.

If `minibuffer-completion-confirm' is `confirm', do not try to
 complete; instead, ask for confirmation and accept any input if
 confirmed.
If `minibuffer-completion-confirm' is `confirm-after-completion',
 do not try to complete; instead, ask for confirmation if the
 preceding minibuffer command was `minibuffer-complete', and
 accept the input otherwise."
563
  (interactive)
564 565 566 567 568 569 570 571 572 573
  (let ((beg (field-beginning))
        (end (field-end)))
    (cond
     ;; Allow user to specify null string
     ((= beg end) (exit-minibuffer))
     ((test-completion (buffer-substring beg end)
                       minibuffer-completion-table
                       minibuffer-completion-predicate)
      (when completion-ignore-case
        ;; Fixup case of the field, if necessary.
574
        (let* ((string (buffer-substring beg end))
575 576 577 578 579 580 581
               (compl (try-completion
                       string
                       minibuffer-completion-table
                       minibuffer-completion-predicate)))
          (when (and (stringp compl)
                     ;; If it weren't for this piece of paranoia, I'd replace
                     ;; the whole thing with a call to do-completion.
582 583 584 585
                     ;; This is important, e.g. when the current minibuffer's
                     ;; content is a directory which only contains a single
                     ;; file, so `try-completion' actually completes to
                     ;; that file.
586
                     (= (length string) (length compl)))
587 588
            (goto-char end)
            (insert compl)
589 590
            (delete-region beg end))))
      (exit-minibuffer))
591

592
     ((eq minibuffer-completion-confirm 'confirm)
593
      ;; The user is permitted to exit with an input that's rejected
594
      ;; by test-completion, after confirming her choice.
595 596 597 598
      (if (eq last-command this-command)
          (exit-minibuffer)
        (minibuffer-message "Confirm")
        nil))
599

600 601 602
     ((eq minibuffer-completion-confirm 'confirm-after-completion)
      ;; Similar to the above, but only if trying to exit immediately
      ;; after typing TAB (this catches most minibuffer typos).
603
      (if (memq last-command minibuffer-confirm-exit-commands)
604 605 606 607
	  (progn (minibuffer-message "Confirm")
		 nil)
	(exit-minibuffer)))

608 609 610 611 612
     (t
      ;; Call do-completion, but ignore errors.
      (case (condition-case nil
                (completion--do-completion)
              (error 1))
613 614 615 616 617
        ((#b001 #b011) (exit-minibuffer))
        (#b111 (if (not minibuffer-completion-confirm)
                   (exit-minibuffer)
                 (minibuffer-message "Confirm")
                 nil))
618 619
        (t nil))))))

620 621 622 623
(defun completion--try-word-completion (string table predicate point)
  (let ((comp (completion-try-completion string table predicate point)))
    (if (not (consp comp))
        comp
624

625 626
      ;; If completion finds next char not unique,
      ;; consider adding a space or a hyphen.
627
      (when (= (length string) (length (car comp)))
628
        (let ((exts '(" " "-"))
629 630
              (before (substring string 0 point))
              (after (substring string point))
631 632
	      ;; Disable partial-completion for this.
	      (completion-styles
633 634
	       (or (remove 'partial-completion completion-styles)
		   completion-styles))
635 636
	      tem)
	  (while (and exts (not (consp tem)))
637
            (setq tem (completion-try-completion
638 639 640
		       (concat before (pop exts) after)
		       table predicate (1+ point))))
	  (if (consp tem) (setq comp tem))))
641

642 643 644 645 646 647 648
      ;; Completing a single word is actually more difficult than completing
      ;; as much as possible, because we first have to find the "current
      ;; position" in `completion' in order to find the end of the word
      ;; we're completing.  Normally, `string' is a prefix of `completion',
      ;; which makes it trivial to find the position, but with fancier
      ;; completion (plus env-var expansion, ...) `completion' might not
      ;; look anything like `string' at all.
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700
      (let* ((comppoint (cdr comp))
	     (completion (car comp))
	     (before (substring string 0 point))
	     (combined (concat before "\n" completion)))
        ;; Find in completion the longest text that was right before point.
        (when (string-match "\\(.+\\)\n.*?\\1" combined)
          (let* ((prefix (match-string 1 before))
                 ;; We used non-greedy match to make `rem' as long as possible.
                 (rem (substring combined (match-end 0)))
                 ;; Find in the remainder of completion the longest text
                 ;; that was right after point.
                 (after (substring string point))
                 (suffix (if (string-match "\\`\\(.+\\).*\n.*\\1"
                                           (concat after "\n" rem))
                             (match-string 1 after))))
            ;; The general idea is to try and guess what text was inserted
            ;; at point by the completion.  Problem is: if we guess wrong,
            ;; we may end up treating as "added by completion" text that was
            ;; actually painfully typed by the user.  So if we then cut
            ;; after the first word, we may throw away things the
            ;; user wrote.  So let's try to be as conservative as possible:
            ;; only cut after the first word, if we're reasonably sure that
            ;; our guess is correct.
            ;; Note: a quick survey on emacs-devel seemed to indicate that
            ;; nobody actually cares about the "word-at-a-time" feature of
            ;; minibuffer-complete-word, whose real raison-d'être is that it
            ;; tries to add "-" or " ".  One more reason to only cut after
            ;; the first word, if we're really sure we're right.
            (when (and (or suffix (zerop (length after)))
                       (string-match (concat
                                      ;; Make submatch 1 as small as possible
                                      ;; to reduce the risk of cutting
                                      ;; valuable text.
                                      ".*" (regexp-quote prefix) "\\(.*?\\)"
                                      (if suffix (regexp-quote suffix) "\\'"))
                                     completion)
                       ;; The new point in `completion' should also be just
                       ;; before the suffix, otherwise something more complex
                       ;; is going on, and we're not sure where we are.
                       (eq (match-end 1) comppoint)
                       ;; (match-beginning 1)..comppoint is now the stretch
                       ;; of text in `completion' that was completed at point.
		       (string-match "\\W" completion (match-beginning 1))
		       ;; Is there really something to cut?
		       (> comppoint (match-end 0)))
              ;; Cut after the first word.
              (let ((cutpos (match-end 0)))
                (setq completion (concat (substring completion 0 cutpos)
                                         (substring completion comppoint)))
                (setq comppoint cutpos)))))

	(cons completion comppoint)))))
701 702 703 704 705 706 707 708


(defun minibuffer-complete-word ()
  "Complete the minibuffer contents at most a single word.
After one word is completed as much as possible, a space or hyphen
is added, provided that matches some possible completion.
Return nil if there is no valid completion, else t."
  (interactive)
709
  (case (completion--do-completion 'completion--try-word-completion)
710 711 712 713 714 715 716 717
    (#b000 nil)
    (#b001 (goto-char (field-end))
           (minibuffer-message "Sole completion")
           t)
    (#b011 (goto-char (field-end))
           (minibuffer-message "Complete, but not unique")
           t)
    (t     t)))
718

719
(defun completion--insert-strings (strings)
720 721 722 723 724 725 726
  "Insert a list of STRINGS into the current buffer.
Uses columns to keep the listing readable but compact.
It also eliminates runs of equal strings."
  (when (consp strings)
    (let* ((length (apply 'max
			  (mapcar (lambda (s)
				    (if (consp s)
727 728 729
					(+ (string-width (car s))
                                           (string-width (cadr s)))
				      (string-width s)))
730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756
				  strings)))
	   (window (get-buffer-window (current-buffer) 0))
	   (wwidth (if window (1- (window-width window)) 79))
	   (columns (min
		     ;; At least 2 columns; at least 2 spaces between columns.
		     (max 2 (/ wwidth (+ 2 length)))
		     ;; Don't allocate more columns than we can fill.
		     ;; Windows can't show less than 3 lines anyway.
		     (max 1 (/ (length strings) 2))))
	   (colwidth (/ wwidth columns))
           (column 0)
	   (laststring nil))
      ;; The insertion should be "sensible" no matter what choices were made
      ;; for the parameters above.
      (dolist (str strings)
	(unless (equal laststring str)  ; Remove (consecutive) duplicates.
	  (setq laststring str)
	  (unless (bolp)
            (insert " \t")
            (setq column (+ column colwidth))
            ;; Leave the space unpropertized so that in the case we're
            ;; already past the goal column, there is still
            ;; a space displayed.
            (set-text-properties (- (point) 1) (point)
                                 ;; We can't just set tab-width, because
                                 ;; completion-setup-function will kill all
                                 ;; local variables :-(
757 758 759 760 761 762 763 764
                                 `(display (space :align-to ,column)))
	    (when (< wwidth (+ (max colwidth
				    (if (consp str)
					(+ (string-width (car str))
					   (string-width (cadr str)))
				      (string-width str)))
			       column))
	      (delete-char -2) (insert "\n") (setq column 0)))
765 766 767 768 769 770 771 772
	  (if (not (consp str))
	      (put-text-property (point) (progn (insert str) (point))
				 'mouse-face 'highlight)
	    (put-text-property (point) (progn (insert (car str)) (point))
			       'mouse-face 'highlight)
	    (put-text-property (point) (progn (insert (cadr str)) (point))
                               'mouse-face nil)))))))

773 774
(defvar completion-common-substring nil)
(make-obsolete-variable 'completion-common-substring nil "23.1")
775

776 777 778 779 780
(defvar completion-setup-hook nil
  "Normal hook run at the end of setting up a completion list buffer.
When this hook is run, the current buffer is the one in which the
command to display the completion list buffer was run.
The completion list buffer is available as the value of `standard-output'.
781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804
See also `display-completion-list'.")

(defface completions-first-difference
  '((t (:inherit bold)))
  "Face put on the first uncommon character in completions in *Completions* buffer."
  :group 'completion)

(defface completions-common-part
  '((t (:inherit default)))
  "Face put on the common prefix substring in completions in *Completions* buffer.
The idea of `completions-common-part' is that you can use it to
make the common parts less visible than normal, so that the rest
of the differing parts is, by contrast, slightly highlighted."
  :group 'completion)

(defun completion-hilit-commonality (completions prefix-len)
  (when completions
    (let* ((last (last completions))
           (base-size (cdr last))
           (com-str-len (- prefix-len (or base-size 0))))
      ;; Remove base-size during mapcar, and add it back later.
      (setcdr last nil)
      (nconc
       (mapcar
805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
        (lambda (elem)
          (let ((str
                 ;; Don't modify the string itself, but a copy, since the
                 ;; the string may be read-only or used for other purposes.
                 ;; Furthermore, since `completions' may come from
                 ;; display-completion-list, `elem' may be a list.
                 (if (consp elem)
                     (car (setq elem (cons (copy-sequence (car elem))
                                           (cdr elem))))
                   (setq elem (copy-sequence elem)))))
            (put-text-property 0 com-str-len
                               'font-lock-face 'completions-common-part
                               str)
            (if (> (length str) com-str-len)
                (put-text-property com-str-len (1+ com-str-len)
                                   'font-lock-face 'completions-first-difference
                                   str)))
          elem)
823 824
        completions)
       base-size))))
825

826
(defun display-completion-list (completions &optional common-substring)
827 828 829 830 831 832 833 834 835 836
  "Display the list of completions, COMPLETIONS, using `standard-output'.
Each element may be just a symbol or string
or may be a list of two strings to be printed as if concatenated.
If it is a list of two strings, the first is the actual completion
alternative, the second serves as annotation.
`standard-output' must be a buffer.
The actual completion alternatives, as inserted, are given `mouse-face'
properties of `highlight'.
At the end, this runs the normal hook `completion-setup-hook'.
It can find the completion buffer in `standard-output'.
837

838
The obsolete optional arg COMMON-SUBSTRING, if non-nil, should be a string
839 840
specifying a common substring for adding the faces
`completions-first-difference' and `completions-common-part' to
841
the completions buffer."
842 843 844
  (if common-substring
      (setq completions (completion-hilit-commonality
                         completions (length common-substring))))
845 846 847 848 849
  (if (not (bufferp standard-output))
      ;; This *never* (ever) happens, so there's no point trying to be clever.
      (with-temp-buffer
	(let ((standard-output (current-buffer))
	      (completion-setup-hook nil))
850
	  (display-completion-list completions common-substring))
851 852
	(princ (buffer-string)))

853 854 855 856 857 858 859 860 861 862 863 864 865
    (let ((mainbuf (current-buffer)))
      (with-current-buffer standard-output
	(goto-char (point-max))
	(if (null completions)
	    (insert "There are no possible completions of what you have typed.")
	  (insert "Possible completions are:\n")
	  (let ((last (last completions)))
	    ;; Set base-size from the tail of the list.
	    (set (make-local-variable 'completion-base-size)
		 (or (cdr last)
		     (and (minibufferp mainbuf) 0)))
	    (setcdr last nil)) ; Make completions a properly nil-terminated list.
	  (completion--insert-strings completions)))))
866

867 868
  ;; The hilit used to be applied via completion-setup-hook, so there
  ;; may still be some code that uses completion-common-substring.
869 870 871
  (with-no-warnings
    (let ((completion-common-substring common-substring))
      (run-hooks 'completion-setup-hook)))
872 873 874 875 876 877 878
  nil)

(defun minibuffer-completion-help ()
  "Display a list of possible completions of the current minibuffer contents."
  (interactive)
  (message "Making completion list...")
  (let* ((string (field-string))
879
         (completions (completion-all-completions
880 881
                       string
                       minibuffer-completion-table
882 883
                       minibuffer-completion-predicate
                       (- (point) (field-beginning)))))
884 885
    (message nil)
    (if (and completions
886 887
             (or (consp (cdr completions))
                 (not (equal (car completions) string))))
888
        (with-output-to-temp-buffer "*Completions*"
889 890 891 892 893 894 895
          (let* ((last (last completions))
                 (base-size (cdr last)))
            ;; Remove the base-size tail because `sort' requires a properly
            ;; nil-terminated list.
            (when last (setcdr last nil))
            (display-completion-list (nconc (sort completions 'string-lessp)
                                            base-size))))
896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918

      ;; If there are no completions, or if the current input is already the
      ;; only possible completion, then hide (previous&stale) completions.
      (let ((window (and (get-buffer "*Completions*")
                         (get-buffer-window "*Completions*" 0))))
        (when (and (window-live-p window) (window-dedicated-p window))
          (condition-case ()
              (delete-window window)
            (error (iconify-frame (window-frame window))))))
      (ding)
      (minibuffer-message
       (if completions "Sole completion" "No completions")))
    nil))

(defun exit-minibuffer ()
  "Terminate this minibuffer argument."
  (interactive)
  ;; If the command that uses this has made modifications in the minibuffer,
  ;; we don't want them to cause deactivation of the mark in the original
  ;; buffer.
  ;; A better solution would be to make deactivate-mark buffer-local
  ;; (or to turn it into a list of buffers, ...), but in the mean time,
  ;; this should do the trick in most cases.
919
  (setq deactivate-mark nil)
920 921 922 923 924 925 926 927 928 929
  (throw 'exit nil))

(defun self-insert-and-exit ()
  "Terminate minibuffer input."
  (interactive)
  (if (characterp last-command-char)
      (call-interactively 'self-insert-command)
    (ding))
  (exit-minibuffer))

930 931
;;; Key bindings.

932 933 934
(define-obsolete-variable-alias 'minibuffer-local-must-match-filename-map
  'minibuffer-local-filename-must-match-map "23.1")

935 936 937 938 939 940 941
(let ((map minibuffer-local-map))
  (define-key map "\C-g" 'abort-recursive-edit)
  (define-key map "\r" 'exit-minibuffer)
  (define-key map "\n" 'exit-minibuffer))

(let ((map minibuffer-local-completion-map))
  (define-key map "\t" 'minibuffer-complete)
942 943 944
  ;; M-TAB is already abused for many other purposes, so we should find
  ;; another binding for it.
  ;; (define-key map "\e\t" 'minibuffer-force-complete)
945 946 947 948 949 950 951 952 953
  (define-key map " " 'minibuffer-complete-word)
  (define-key map "?" 'minibuffer-completion-help))

(let ((map minibuffer-local-must-match-map))
  (define-key map "\r" 'minibuffer-complete-and-exit)
  (define-key map "\n" 'minibuffer-complete-and-exit))

(let ((map minibuffer-local-filename-completion-map))
  (define-key map " " nil))
954
(let ((map minibuffer-local-filename-must-match-map))
955 956 957 958 959 960 961 962 963
  (define-key map " " nil))

(let ((map minibuffer-local-ns-map))
  (define-key map " " 'exit-minibuffer)
  (define-key map "\t" 'exit-minibuffer)
  (define-key map "?" 'self-insert-and-exit))

;;; Completion tables.

964 965 966
(defun minibuffer--double-dollars (str)
  (replace-regexp-in-string "\\$" "$$" str))

967 968 969 970 971
(defun completion--make-envvar-table ()
  (mapcar (lambda (enventry)
            (substring enventry 0 (string-match "=" enventry)))
          process-environment))

972 973 974 975
(defconst completion--embedded-envvar-re
  (concat "\\(?:^\\|[^$]\\(?:\\$\\$\\)*\\)"
          "$\\([[:alnum:]_]*\\|{\\([^}]*\\)\\)\\'"))

976
(defun completion--embedded-envvar-table (string pred action)
977 978 979
  (if (eq (car-safe action) 'boundaries)
      ;; Compute the boundaries of the subfield to which this
      ;; completion applies.
980 981 982 983
      (let ((suffix (cdr action)))
        (if (string-match completion--embedded-envvar-re string)
            (list* 'boundaries
                   (or (match-beginning 2) (match-beginning 1))
984
                   (when (string-match "[^[:alnum:]_]" suffix)
985
                     (match-beginning 0)))))
986 987 988 989 990 991 992 993 994
    (when (string-match completion--embedded-envvar-re string)
      (let* ((beg (or (match-beginning 2) (match-beginning 1)))
             (table (completion--make-envvar-table))
             (prefix (substring string 0 beg)))
        (if (eq (aref string (1- beg)) ?{)
            (setq table (apply-partially 'completion-table-with-terminator
                                         "}" table)))
        (completion-table-with-context
         prefix table (substring string beg) pred action)))))
995

996
(defun completion--file-name-table (string pred action)
997
  "Internal subroutine for `read-file-name'.  Do not call this."
998 999 1000 1001 1002 1003
  (cond
   ((and (zerop (length string)) (eq 'lambda action))
    nil)                                ; FIXME: why?
   ((eq (car-safe action) 'boundaries)
    ;; FIXME: Actually, this is not always right in the presence of
    ;; envvars, but there's not much we can do, I think.
1004 1005
    (let ((start (length (file-name-directory string)))
          (end (string-match "/" (cdr action))))
1006
      (list* 'boundaries start end)))
1007

1008
   (t
1009 1010 1011 1012 1013 1014
    (let* ((dir (if (stringp pred)
                    ;; It used to be that `pred' was abused to pass `dir'
                    ;; as an argument.
                    (prog1 (expand-file-name pred) (setq pred nil))
                  default-directory))
           (str (condition-case nil
1015 1016
                    (substitute-in-file-name string)
                  (error string)))
1017 1018 1019 1020
           (name (file-name-nondirectory str))
           (specdir (file-name-directory str))
           (realdir (if specdir (expand-file-name specdir dir)
                      (file-name-as-directory dir))))
1021

1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035
      (cond
       ((null action)
        (let ((comp (file-name-completion name realdir
                                          read-file-name-predicate)))
          (if (stringp comp)
              ;; Requote the $s before returning the completion.
              (minibuffer--double-dollars (concat specdir comp))
            ;; Requote the $s before checking for changes.
            (setq str (minibuffer--double-dollars str))
            (if (string-equal string str)
                comp
              ;; If there's no real completion, but substitute-in-file-name
              ;; changed the string, then return the new string.
              str))))
1036

1037
       ((eq action t)
1038
        (let ((all (file-name-all-completions name realdir))
1039 1040
              ;; FIXME: Actually, this is not always right in the presence
              ;; of envvars, but there's not much we can do, I think.
1041 1042 1043 1044
              (base-size (length (file-name-directory string))))

          ;; Check the predicate, if necessary.
          (unless (memq read-file-name-predicate '(nil file-exists-p))
1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057
            (let ((comp ())
                  (pred
                   (if (eq read-file-name-predicate 'file-directory-p)
                       ;; Brute-force speed up for directory checking:
                       ;; Discard strings which don't end in a slash.
                       (lambda (s)
                         (let ((len (length s)))
                           (and (> len 0) (eq (aref s (1- len)) ?/))))
                     ;; Must do it the hard (and slow) way.
                     read-file-name-predicate)))
              (let ((default-directory realdir))
                (dolist (tem all)
                  (if (funcall pred tem) (push tem comp))))
1058 1059
              (setq all (nreverse comp))))

1060 1061
          (if (and completion-all-completions-with-base-size (consp all))
              ;; Add base-size, but only if the list is non-empty.
1062 1063
              (nconc all base-size)
            all)))
1064 1065 1066 1067

       (t
        ;; Only other case actually used is ACTION = lambda.
        (let ((default-directory dir))
1068
          (funcall (or read-file-name-predicate 'file-exists-p) str))))))))
1069

1070
(defalias 'read-file-name-internal
1071
  (completion-table-in-turn 'completion--embedded-envvar-table
1072
                            'completion--file-name-table)
1073
  "Internal subroutine for `read-file-name'.  Do not call this.")
1074

1075 1076 1077 1078 1079 1080 1081
(defvar read-file-name-function nil
  "If this is non-nil, `read-file-name' does its work by calling this function.")

(defvar read-file-name-predicate nil
  "Current predicate used by `read-file-name-internal'.")

(defcustom read-file-name-completion-ignore-case
1082
  (if (memq system-type '(ms-dos windows-nt darwin cygwin))
1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112
      t nil)
  "Non-nil means when reading a file name completion ignores case."
  :group 'minibuffer
  :type 'boolean
  :version "22.1")

(defcustom insert-default-directory t
  "Non-nil means when reading a filename start with default dir in minibuffer.

When the initial minibuffer contents show a name of a file or a directory,
typing RETURN without editing the initial contents is equivalent to typing
the default file name.

If this variable is non-nil, the minibuffer contents are always
initially non-empty, and typing RETURN without editing will fetch the
default name, if one is provided.  Note however that this default name
is not necessarily the same as initial contents inserted in the minibuffer,
if the initial contents is just the default directory.

If this variable is nil, the minibuffer often starts out empty.  In
that case you may have to explicitly fetch the next history element to
request the default name; typing RETURN without editing will leave
the minibuffer empty.

For some commands, exiting with an empty minibuffer has a special meaning,
such as making the current buffer visit no file in the case of
`set-visited-file-name'."
  :group 'minibuffer
  :type 'boolean)

1113 1114 1115 1116
;; Not always defined, but only called if next-read-file-uses-dialog-p says so.
(declare-function x-file-dialog "xfns.c"
                  (prompt dir &optional default-filename mustmatch only-dir-p))

1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148
(defun read-file-name (prompt &optional dir default-filename mustmatch initial predicate)
  "Read file name, prompting with PROMPT and completing in directory DIR.
Value is not expanded---you must call `expand-file-name' yourself.
Default name to DEFAULT-FILENAME if user exits the minibuffer with
the same non-empty string that was inserted by this function.
 (If DEFAULT-FILENAME is omitted, the visited file name is used,
  except that if INITIAL is specified, that combined with DIR is used.)
If the user exits with an empty minibuffer, this function returns
an empty string.  (This can only happen if the user erased the
pre-inserted contents or if `insert-default-directory' is nil.)
Fourth arg MUSTMATCH non-nil means require existing file's name.
 Non-nil and non-t means also require confirmation after completion.
Fifth arg INITIAL specifies text to start with.
If optional sixth arg PREDICATE is non-nil, possible completions and
the resulting file name must satisfy (funcall PREDICATE NAME).
DIR should be an absolute directory name.  It defaults to the value of
`default-directory'.

If this command was invoked with the mouse, use a file dialog box if
`use-dialog-box' is non-nil, and the window system or X toolkit in use
provides a file dialog box.

See also `read-file-name-completion-ignore-case'
and `read-file-name-function'."
  (unless dir (setq dir default-directory))
  (unless (file-name-absolute-p dir) (setq dir (expand-file-name dir)))
  (unless default-filename
    (setq default-filename (if initial (expand-file-name initial dir)
                             buffer-file-name)))
  ;; If dir starts with user's homedir, change that to ~.
  (setq dir (abbreviate-file-name dir))
  ;; Likewise for default-filename.
1149 1150
  (if default-filename
      (setq default-filename (abbreviate-file-name default-filename)))
1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161
  (let ((insdef (cond
                 ((and insert-default-directory (stringp dir))
                  (if initial
                      (cons (minibuffer--double-dollars (concat dir initial))
                            (length (minibuffer--double-dollars dir)))
                    (minibuffer--double-dollars dir)))
                 (initial (cons (minibuffer--double-dollars initial) 0)))))

    (if read-file-name-function
        (funcall read-file-name-function
                 prompt dir default-filename mustmatch initial predicate)
1162
      (let ((completion-ignore-case read-file-name-completion-ignore-case)
1163 1164 1165 1166 1167 1168
            (minibuffer-completing-file-name t)
            (read-file-name-predicate (or predicate 'file-exists-p))
            (add-to-history nil))

        (let* ((val
                (if (not (next-read-file-uses-dialog-p))
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180
                    ;; We used to pass `dir' to `read-file-name-internal' by
                    ;; abusing the `predicate' argument.  It's better to
                    ;; just use `default-directory', but in order to avoid
                    ;; changing `default-directory' in the current buffer,
                    ;; we don't let-bind it.
                    (lexical-let ((dir (file-name-as-directory
                                        (expand-file-name dir))))
                      (minibuffer-with-setup-hook
                          (lambda () (setq default-directory dir))
                        (completing-read prompt 'read-file-name-internal
                                         nil mustmatch insdef 'file-name-history
                                         default-filename)))
1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232
                  ;; If DIR contains a file name, split it.
                  (let ((file (file-name-nondirectory dir)))
                    (when (and default-filename (not (zerop (length file))))
                      (setq default-filename file)
                      (setq dir (file-name-directory dir)))
                    (if default-filename
                        (setq default-filename
                              (expand-file-name default-filename dir)))
                    (setq add-to-history t)
                    (x-file-dialog prompt dir default-filename mustmatch
                                   (eq predicate 'file-directory-p)))))

               (replace-in-history (eq (car-safe file-name-history) val)))
          ;; If completing-read returned the inserted default string itself
          ;; (rather than a new string with the same contents),
          ;; it has to mean that the user typed RET with the minibuffer empty.
          ;; In that case, we really want to return ""
          ;; so that commands such as set-visited-file-name can distinguish.
          (when (eq val default-filename)
            ;; In this case, completing-read has not added an element
            ;; to the history.  Maybe we should.
            (if (not replace-in-history)
                (setq add-to-history t))
            (setq val ""))
          (unless val (error "No file name specified"))

          (if (and default-filename
                   (string-equal val (if (consp insdef) (car insdef) insdef)))
              (setq val default-filename))
          (setq val (substitute-in-file-name val))

          (if replace-in-history
              ;; Replace what Fcompleting_read added to the history
              ;; with what we will actually return.
              (let ((val1 (minibuffer--double-dollars val)))
                (if history-delete-duplicates
                    (setcdr file-name-history
                            (delete val1 (cdr file-name-history))))
                (setcar file-name-history val1))
            (if add-to-history
                ;; Add the value to the history--but not if it matches
                ;; the last value already there.
                (let ((val1 (minibuffer--double-dollars val)))
                  (unless (and (consp file-name-history)
                               (equal (car file-name-history) val1))
                    (setq file-name-history
                          (cons val1
                                (if history-delete-duplicates
                                    (delete val1 file-name-history)
                                  file-name-history)))))))
          val)))))

1233 1234 1235 1236 1237 1238 1239 1240 1241 1242
(defun internal-complete-buffer-except (&optional buffer)
  "Perform completion on all buffers excluding BUFFER.
Like `internal-complete-buffer', but removes BUFFER from the completion list."
  (lexical-let ((except (if (stringp buffer) buffer (buffer-name buffer))))
    (apply-partially 'completion-table-with-predicate
		     'internal-complete-buffer
		     (lambda (name)
		       (not (equal (if (consp name) (car name) name) except)))
		     nil)))

1243
;;; Old-style completion, used in Emacs-21 and Emacs-22.
1244 1245 1246 1247 1248 1249 1250 1251

(defun completion-emacs21-try-completion (string table pred point)
  (let ((completion (try-completion string table pred)))
    (if (stringp completion)
        (cons completion (length completion))
      completion)))

(defun completion-emacs21-all-completions (string table pred point)
1252
  (completion-hilit-commonality
1253
   (all-completions string table pred)
1254
   (length string)))
1255 1256 1257 1258 1259 1260 1261 1262 1263

(defun completion-emacs22-try-completion (string table pred point)
  (let ((suffix (substring string point))
        (completion (try-completion (substring string 0 point) table pred)))
    (if (not (stringp completion))
        completion
      ;; Merge a trailing / in completion with a / after point.
      ;; We used to only do it for word completion, but it seems to make
      ;; sense for all completions.
1264 1265 1266 1267 1268 1269
      ;; Actually, claiming this feature was part of Emacs-22 completion
      ;; is pushing it a bit: it was only done in minibuffer-completion-word,
      ;; which was (by default) not bound during file completion, where such
      ;; slashes are most likely to occur.
      (if (and (not (zerop (length completion)))
               (eq ?/ (aref completion (1- (length completion))))
1270 1271
               (not (zerop (length suffix)))
               (eq ?/ (aref suffix 0)))
1272 1273
          ;; This leaves point after the / .
          (setq suffix (substring suffix 1)))
1274 1275 1276
      (cons (concat completion suffix) (length completion)))))

(defun completion-emacs22-all-completions (string table pred point)
1277
  (completion-hilit-commonality
1278
   (all-completions (substring string 0 point) table pred)
1279
   point))
1280

1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297
;;; Basic completion.

(defun completion--merge-suffix (completion point suffix)
  "Merge end of COMPLETION with beginning of SUFFIX.
Simple generalization of the \"merge trailing /\" done in Emacs-22.
Return the new suffix."
  (if (and (not (zerop (length suffix)))
           (string-match "\\(.+\\)\n\\1" (concat completion "\n" suffix)
                         ;; Make sure we don't compress things to less
                         ;; than we started with.
                         point)
           ;; Just make sure we didn't match some other \n.
           (eq (match-end 1) (length completion)))
      (substring suffix (- (match-end 1) (match-beginning 1)))
    ;; Nothing to merge.
    suffix))

1298
(defun completion-basic-try-completion (string table pred point)
1299 1300
  (let* ((beforepoint (substring string 0 point))
         (afterpoint (substring string point))
1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336
         (bounds (completion-boundaries beforepoint table pred afterpoint)))
    (if (zerop (cdr bounds))
        ;; `try-completion' may return a subtly different result
        ;; than `all+merge', so try to use it whenever possible.
        (let ((completion (try-completion beforepoint table pred)))
          (if (not (stringp completion))
              completion
            (cons
             (concat completion
                     (completion--merge-suffix completion point afterpoint))
             (length completion))))
      (let* ((suffix (substring afterpoint (cdr bounds)))
             (prefix (substring beforepoint 0 (car bounds)))
             (pattern (delete
                       "" (list (substring beforepoint (car bounds))
                                'point
                                (substring afterpoint 0 (cdr bounds)))))
             (all (completion-pcm--all-completions prefix pattern table pred)))
        (if minibuffer-completing-file-name
            (setq all (completion-pcm--filename-try-filter all)))
        (completion-pcm--merge-try pattern all prefix suffix)))))

(defun completion-basic-all-completions (string table pred point)
  (let* ((beforepoint (substring string 0 point))
         (afterpoint (substring string point))
         (bounds (completion-boundaries beforepoint table pred afterpoint))
         (suffix (substring afterpoint (cdr bounds)))
         (prefix (substring beforepoint 0 (car bounds)))
         (pattern (delete
                   "" (list (substring beforepoint (car bounds))
                            'point
                            (substring afterpoint 0 (cdr bounds)))))
         (all (completion-pcm--all-completions prefix pattern table pred)))
    (completion-hilit-commonality
     (if (consp all) (nconc all (car bounds)) all)
     point)))
1337

1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357
;;; Partial-completion-mode style completion.

(defvar completion-pcm--delim-wild-regex nil)

(defun completion-pcm--prepare-delim-re (delims)
  (setq completion-pcm--delim-wild-regex (concat "[" delims "*]")))

(defcustom completion-pcm-word-delimiters "-_. "
  "A string of characters treated as word delimiters for completion.
Some arcane rules:
If `]' is in this string, it must come first.
If `^' is in this string, it must not come first.
If `-' is in this string, it must come first or right after `]'.
In other words, if S is this string, then `[S]' must be a valid Emacs regular
expression (not containing character ranges like `a-z')."
  :set (lambda (symbol value)
         (set-default symbol value)
         ;; Refresh other vars.
         (completion-pcm--prepare-delim-re value))
  :initialize 'custom-initialize-reset
1358
  :group 'minibuffer
1359 1360 1361 1362 1363
  :type 'string)

(defun completion-pcm--pattern-trivial-p (pattern)
  (and (stringp (car pattern)) (null (cdr pattern))))

1364 1365
(defun completion-pcm--string->pattern (string &optional point)
  "Split STRING into a pattern.
1366 1367
<