lisp/icomplete.el

   1 ;;; icomplete.el --- minibuffer completion incremental feedback
   2
   3 ;; Copyright (C) 1992-1994, 1997, 1999, 2001-2018 Free Software
   4 ;; Foundation, Inc.
   5
   6 ;; Author: Ken Manheimer <klm@i.am>
   7 ;; Maintainer: Ken Manheimer <klm@i.am>
   8 ;; Created: Mar 1993 Ken Manheimer, klm@nist.gov - first release to usenet
   9 ;; Keywords: help, abbrev
  10
  11 ;; This file is part of GNU Emacs.
  12
  13 ;; GNU Emacs is free software: you can redistribute it and/or modify
  14 ;; it under the terms of the GNU General Public License as published by
  15 ;; the Free Software Foundation, either version 3 of the License, or
  16 ;; (at your option) any later version.
  17
  18 ;; GNU Emacs is distributed in the hope that it will be useful,
  19 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 ;; GNU General Public License for more details.
  22
  23 ;; You should have received a copy of the GNU General Public License
  24 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  25
  26 ;;; Commentary:
  27
  28 ;; Enabling this package implements a more fine-grained minibuffer
  29 ;; completion feedback scheme.  Prospective completions are concisely
  30 ;; indicated within the minibuffer itself, with each successive
  31 ;; keystroke.
  32
  33 ;; See `icomplete-completions' docstring for a description of the
  34 ;; icomplete display format.
  35
  36 ;; See the `icomplete-minibuffer-setup-hook' docstring for a means to
  37 ;; customize icomplete setup for interoperation with other
  38 ;; minibuffer-oriented packages.
  39
  40 ;; To enable/disable icomplete mode, use the `icomplete-mode' function.
  41
  42 ;; Thanks to everyone for their suggestions for refinements of this
  43 ;; package.  I particularly have to credit Michael Cook, who
  44 ;; implemented an incremental completion style in his 'iswitch'
  45 ;; functions that served as a model for icomplete.  Some other
  46 ;; contributors: Noah Friedman (restructuring as minor mode), Colin
  47 ;; Rafferty (lemacs reconciliation), Lars Lindberg, RMS, and others.
  48
  49 ;; klm.
  50
  51 ;;; Code:
  52
  53 (defgroup icomplete nil
  54   "Show completions dynamically in minibuffer."
  55   :prefix "icomplete-"
  56   :link '(info-link "(emacs)Icomplete")
  57   :group 'minibuffer)
  58
  59 (defcustom icomplete-separator " | "
  60   "String used by Icomplete to separate alternatives in the minibuffer."
  61   :type 'string
  62   :version "24.4")
  63
  64 (defcustom icomplete-hide-common-prefix t
  65   "When non-nil, hide common prefix from completion candidates.
  66 When nil, show candidates in full."
  67   :type 'boolean
  68   :version "24.4")
  69
  70 (defcustom icomplete-show-matches-on-no-input nil
  71   "When non-nil, show completions when first prompting for input."
  72   :type 'boolean
  73   :version "24.4")
  74
  75 (defcustom icomplete-with-completion-tables t
  76   "Specialized completion tables with which Icomplete should operate.
  77 If this is t, Icomplete operates on all tables.
  78 Otherwise this should be a list of the completion tables (e.g.,
  79 `internal-complete-buffer') on which Icomplete should operate."
  80   ;; Prior to 24.4, not a user-option, default '(internal-complete-buffer).
  81   :version "24.4"
  82   :type '(choice (const :tag "All" t)
  83                  (repeat function)))
  84
  85 (defface icomplete-first-match '((t :weight bold))
  86   "Face used by Icomplete for highlighting first match."
  87   :version "24.4")
  88
  89 ;;;_* User Customization variables
  90 (defcustom icomplete-prospects-height 2
  91   ;; We used to compute how many lines 100 characters would take in
  92   ;; the current window width, but the return value of `window-width'
  93   ;; is unreliable on startup (e.g., if we're in daemon mode), so now
  94   ;; we simply base the default value on an 80 column window.
  95   "Maximum number of lines to use in the minibuffer."
  96   :type 'integer
  97   :version "26.1")
  98
  99 (defcustom icomplete-compute-delay .3
 100   "Completions-computation stall, used only with large-number completions.
 101 See `icomplete-delay-completions-threshold'."
 102   :type 'number)
 103
 104 (defcustom icomplete-delay-completions-threshold 400
 105   "Pending-completions number over which to apply `icomplete-compute-delay'."
 106   :type 'integer)
 107
 108 (defcustom icomplete-max-delay-chars 3
 109   "Maximum number of initial chars to apply `icomplete-compute-delay'."
 110   :type 'integer)
 111
 112 (defvar icomplete-in-buffer nil
 113   "If non-nil, also use Icomplete when completing in non-mini buffers.")
 114
 115 (defcustom icomplete-minibuffer-setup-hook nil
 116   "Icomplete-specific customization of minibuffer setup.
 117
 118 This hook is run during minibuffer setup if Icomplete is active.
 119 It is intended for use in customizing Icomplete for interoperation
 120 with other features and packages.  For instance:
 121
 122   (add-hook \\='icomplete-minibuffer-setup-hook
 123              (lambda () (setq-local max-mini-window-height 3)))
 124
 125 will constrain Emacs to a maximum minibuffer height of 3 lines when
 126 icompletion is occurring."
 127   :type 'hook
 128   :group 'icomplete)
 129
 130
 131 ;;;_* Initialization
 132
 133 ;;;_ + Internal Variables
 134 ;;;_  = icomplete-eoinput nil
 135 (defvar icomplete-overlay (make-overlay (point-min) (point-min) nil t t)
 136   "Overlay used to display the list of completions.")
 137
 138 (defun icomplete-pre-command-hook ()
 139  (let ((non-essential t))
 140    (icomplete-tidy)))
 141
 142 (defun icomplete-post-command-hook ()
 143   (let ((non-essential t)) ;E.g. don't prompt for password!
 144     (icomplete-exhibit)))
 145
 146 (defvar icomplete-minibuffer-map
 147   (let ((map (make-sparse-keymap)))
 148     (define-key map [?\M-\t] 'minibuffer-force-complete)
 149     (define-key map [?\C-j]  'icomplete-force-complete-and-exit)
 150     (define-key map [?\C-.]  'icomplete-forward-completions)
 151     (define-key map [?\C-,]  'icomplete-backward-completions)
 152     map)
 153   "Keymap used by `icomplete-mode' in the minibuffer.")
 154
 155 (defun icomplete-force-complete-and-exit ()
 156   "Complete the minibuffer and exit.
 157 Use the first of the matches if there are any displayed, and use
 158 the default otherwise."
 159   (interactive)
 160   (if (or icomplete-show-matches-on-no-input
 161           (> (icomplete--field-end) (icomplete--field-beg)))
 162       (minibuffer-force-complete-and-exit)
 163     (minibuffer-complete-and-exit)))
 164
 165 (defun icomplete-forward-completions ()
 166   "Step forward completions by one entry.
 167 Second entry becomes the first and can be selected with
 168 `icomplete-force-complete-and-exit'."
 169   (interactive)
 170   (let* ((beg (icomplete--field-beg))
 171          (end (icomplete--field-end))
 172          (comps (completion-all-sorted-completions beg end))
 173          (last (last comps)))
 174     (when comps
 175       (setcdr last (cons (car comps) (cdr last)))
 176       (completion--cache-all-sorted-completions beg end (cdr comps)))))
 177
 178 (defun icomplete-backward-completions ()
 179   "Step backward completions by one entry.
 180 Last entry becomes the first and can be selected with
 181 `icomplete-force-complete-and-exit'."
 182   (interactive)
 183   (let* ((beg (icomplete--field-beg))
 184          (end (icomplete--field-end))
 185          (comps (completion-all-sorted-completions beg end))
 186          (last-but-one (last comps 2))
 187          (last (cdr last-but-one)))
 188     (when (consp last)                ; At least two elements in comps
 189       (setcdr last-but-one (cdr last))
 190       (push (car last) comps)
 191       (completion--cache-all-sorted-completions beg end comps))))
 192
 193 ;;;_ > icomplete-mode (&optional prefix)
 194 ;;;###autoload
 195 (define-minor-mode icomplete-mode
 196   "Toggle incremental minibuffer completion (Icomplete mode).
 197 With a prefix argument ARG, enable Icomplete mode if ARG is
 198 positive, and disable it otherwise.  If called from Lisp, enable
 199 the mode if ARG is omitted or nil.
 200
 201 When this global minor mode is enabled, typing in the minibuffer
 202 continuously displays a list of possible completions that match
 203 the string you have typed.  See `icomplete-completions' for a
 204 description of how prospective completions are displayed.
 205
 206 For more information, see Info node `(emacs)Icomplete'.
 207 For options you can set, `\\[customize-group] icomplete'.
 208
 209 You can use the following key bindings to navigate and select
 210 completions:
 211
 212 \\{icomplete-minibuffer-map}"
 213   :global t :group 'icomplete
 214   (remove-hook 'minibuffer-setup-hook #'icomplete-minibuffer-setup)
 215   (remove-hook 'completion-in-region-mode-hook #'icomplete--in-region-setup)
 216   (when icomplete-mode
 217     (when icomplete-in-buffer
 218       (add-hook 'completion-in-region-mode-hook #'icomplete--in-region-setup))
 219     (add-hook 'minibuffer-setup-hook #'icomplete-minibuffer-setup)))
 220
 221 (defun icomplete--completion-table ()
 222   (if (window-minibuffer-p) minibuffer-completion-table
 223     (or (nth 2 completion-in-region--data)
 224         (message "In %S (w=%S): %S"
 225                  (current-buffer) (selected-window) (window-minibuffer-p)))))
 226 (defun icomplete--completion-predicate ()
 227   (if (window-minibuffer-p) minibuffer-completion-predicate
 228     (nth 3 completion-in-region--data)))
 229 (defun icomplete--field-string ()
 230   (if (window-minibuffer-p) (minibuffer-contents)
 231     (buffer-substring-no-properties
 232      (nth 0 completion-in-region--data)
 233      (nth 1 completion-in-region--data))))
 234 (defun icomplete--field-beg ()
 235   (if (window-minibuffer-p) (minibuffer-prompt-end)
 236     (nth 0 completion-in-region--data)))
 237 (defun icomplete--field-end ()
 238   (if (window-minibuffer-p) (point-max)
 239     (nth 1 completion-in-region--data)))
 240
 241 ;;;_ > icomplete-simple-completing-p ()
 242 (defun icomplete-simple-completing-p ()
 243   "Non-nil if current window is a minibuffer that's doing simple completion.
 244
 245 Conditions are:
 246    the selected window is a minibuffer,
 247    and not in the middle of macro execution,
 248    and the completion table is not a function (which would
 249        indicate some non-standard, non-simple completion mechanism,
 250        like file-name and other custom-func completions),
 251    and `icomplete-with-completion-tables' doesn't restrict completion."
 252
 253   (unless executing-kbd-macro
 254     (let ((table (icomplete--completion-table)))
 255       (and table
 256            (or (not (functionp table))
 257                (eq icomplete-with-completion-tables t)
 258                (member table icomplete-with-completion-tables))))))
 259
 260 ;;;_ > icomplete-minibuffer-setup ()
 261 (defun icomplete-minibuffer-setup ()
 262   "Run in minibuffer on activation to establish incremental completion.
 263 Usually run by inclusion in `minibuffer-setup-hook'."
 264   (when (and icomplete-mode (icomplete-simple-completing-p))
 265     (set (make-local-variable 'completion-show-inline-help) nil)
 266     (use-local-map (make-composed-keymap icomplete-minibuffer-map
 267                                          (current-local-map)))
 268     (add-hook 'pre-command-hook  #'icomplete-pre-command-hook  nil t)
 269     (add-hook 'post-command-hook #'icomplete-post-command-hook nil t)
 270     (run-hooks 'icomplete-minibuffer-setup-hook)
 271     (when icomplete-show-matches-on-no-input
 272       (icomplete-exhibit))))
 273
 274 (defvar icomplete--in-region-buffer nil)
 275
 276 (defun icomplete--in-region-setup ()
 277   (when (or (not completion-in-region-mode)
 278             (and icomplete--in-region-buffer
 279                  (not (eq icomplete--in-region-buffer (current-buffer)))))
 280     (with-current-buffer (or icomplete--in-region-buffer (current-buffer))
 281       (setq icomplete--in-region-buffer nil)
 282       (delete-overlay icomplete-overlay)
 283       (kill-local-variable 'completion-show-inline-help)
 284       (remove-hook 'pre-command-hook  'icomplete-pre-command-hook  t)
 285       (remove-hook 'post-command-hook 'icomplete-post-command-hook t)
 286       (message nil)))
 287   (when (and completion-in-region-mode
 288              icomplete-mode (icomplete-simple-completing-p))
 289     (setq icomplete--in-region-buffer (current-buffer))
 290     (set (make-local-variable 'completion-show-inline-help) nil)
 291     (let ((tem (assq 'completion-in-region-mode
 292                      minor-mode-overriding-map-alist)))
 293       (unless (memq icomplete-minibuffer-map (cdr tem))
 294         (setcdr tem (make-composed-keymap icomplete-minibuffer-map
 295                                           (cdr tem)))))
 296     (add-hook 'pre-command-hook  'icomplete-pre-command-hook  nil t)
 297     (add-hook 'post-command-hook 'icomplete-post-command-hook nil t)))
 298 \f
 299
 300
 301 ;;;_* Completion
 302
 303 ;;;_ > icomplete-tidy ()
 304 (defun icomplete-tidy ()
 305   "Remove completions display (if any) prior to new user input.
 306 Should be run in on the minibuffer `pre-command-hook'.
 307 See `icomplete-mode' and `minibuffer-setup-hook'."
 308   (delete-overlay icomplete-overlay))
 309
 310 ;;;_ > icomplete-exhibit ()
 311 (defun icomplete-exhibit ()
 312   "Insert Icomplete completions display.
 313 Should be run via minibuffer `post-command-hook'.
 314 See `icomplete-mode' and `minibuffer-setup-hook'."
 315   (when (and icomplete-mode
 316              (icomplete-simple-completing-p)) ;Shouldn't be necessary.
 317     (save-excursion
 318       (goto-char (point-max))
 319                                         ; Insert the match-status information:
 320       (if (and (or icomplete-show-matches-on-no-input
 321                    (> (icomplete--field-end) (icomplete--field-beg)))
 322                (or
 323                 ;; Don't bother with delay after certain number of chars:
 324                 (> (- (point) (icomplete--field-beg))
 325                    icomplete-max-delay-chars)
 326                 ;; Don't delay if the completions are known.
 327                 completion-all-sorted-completions
 328                 ;; Don't delay if alternatives number is small enough:
 329                 (and (sequencep (icomplete--completion-table))
 330                      (< (length (icomplete--completion-table))
 331                         icomplete-delay-completions-threshold))
 332                 ;; Delay - give some grace time for next keystroke, before
 333                 ;; embarking on computing completions:
 334                 (sit-for icomplete-compute-delay)))
 335           (let* ((field-string (icomplete--field-string))
 336                  (text (while-no-input
 337                          (icomplete-completions
 338                           field-string
 339                           (icomplete--completion-table)
 340                           (icomplete--completion-predicate)
 341                           (if (window-minibuffer-p)
 342                               (not minibuffer-completion-confirm)))))
 343                  (buffer-undo-list t)
 344                  deactivate-mark)
 345             ;; Do nothing if while-no-input was aborted.
 346             (when (stringp text)
 347               (move-overlay icomplete-overlay (point) (point) (current-buffer))
 348               ;; The current C cursor code doesn't know to use the overlay's
 349               ;; marker's stickiness to figure out whether to place the cursor
 350               ;; before or after the string, so let's spoon-feed it the pos.
 351               (put-text-property 0 1 'cursor t text)
 352               (overlay-put icomplete-overlay 'after-string text)))))))
 353
 354 ;;;_ > icomplete-completions (name candidates predicate require-match)
 355 (defun icomplete-completions (name candidates predicate require-match)
 356   "Identify prospective candidates for minibuffer completion.
 357
 358 The display is updated with each minibuffer keystroke during
 359 minibuffer completion.
 360
 361 Prospective completion suffixes (if any) are displayed, bracketed by
 362 one of (), [], or {} pairs.  The choice of brackets is as follows:
 363
 364   (...) - a single prospect is identified and matching is enforced,
 365   [...] - a single prospect is identified but matching is optional, or
 366   {...} - multiple prospects, separated by commas, are indicated, and
 367           further input is required to distinguish a single one.
 368
 369 If there are multiple possibilities, `icomplete-separator' separates them.
 370
 371 The displays for unambiguous matches have ` [Matched]' appended
 372 \(whether complete or not), or ` [No matches]', if no eligible
 373 matches exist."
 374   (let* ((minibuffer-completion-table candidates)
 375          (minibuffer-completion-predicate predicate)
 376          (md (completion--field-metadata (icomplete--field-beg)))
 377          (comps (completion-all-sorted-completions
 378                  (icomplete--field-beg) (icomplete--field-end)))
 379          (last (if (consp comps) (last comps)))
 380          (base-size (cdr last))
 381          (open-bracket (if require-match "(" "["))
 382          (close-bracket (if require-match ")" "]")))
 383     ;; `concat'/`mapconcat' is the slow part.
 384     (if (not (consp comps))
 385         (progn ;;(debug (format "Candidates=%S field=%S" candidates name))
 386                (format " %sNo matches%s" open-bracket close-bracket))
 387       (if last (setcdr last nil))
 388       (when (and minibuffer-completing-file-name
 389                  icomplete-with-completion-tables)
 390         (setq comps (completion-pcm--filename-try-filter comps)))
 391       (let* ((most-try
 392               (if (and base-size (> base-size 0))
 393                   (completion-try-completion
 394                    name candidates predicate (length name) md)
 395                 ;; If the `comps' are 0-based, the result should be
 396                 ;; the same with `comps'.
 397                 (completion-try-completion
 398                  name comps nil (length name) md)))
 399              (most (if (consp most-try) (car most-try)
 400                      (if most-try (car comps) "")))
 401              ;; Compare name and most, so we can determine if name is
 402              ;; a prefix of most, or something else.
 403              (compare (compare-strings name nil nil
 404                                        most nil nil completion-ignore-case))
 405              (ellipsis (if (char-displayable-p ?…) "…" "..."))
 406              (determ (unless (or (eq t compare) (eq t most-try)
 407                                  (= (setq compare (1- (abs compare)))
 408                                     (length most)))
 409                        (concat open-bracket
 410                                (cond
 411                                 ((= compare (length name))
 412                                  ;; Typical case: name is a prefix.
 413                                  (substring most compare))
 414                                 ;; Don't bother truncating if it doesn't gain
 415                                 ;; us at least 2 columns.
 416                                 ((< compare (+ 2 (string-width ellipsis))) most)
 417                                 (t (concat ellipsis (substring most compare))))
 418                                close-bracket)))
 419              ;;"-prospects" - more than one candidate
 420              (prospects-len (+ (string-width
 421                                 (or determ (concat open-bracket close-bracket)))
 422                                (string-width icomplete-separator)
 423                                (+ 2 (string-width ellipsis)) ;; take {…} into account
 424                                (string-width (buffer-string))))
 425              (prospects-max
 426               ;; Max total length to use, including the minibuffer content.
 427               (* (+ icomplete-prospects-height
 428                     ;; If the minibuffer content already uses up more than
 429                     ;; one line, increase the allowable space accordingly.
 430                     (/ prospects-len (window-width)))
 431                  (window-width)))
 432              ;; Find the common prefix among `comps'.
 433              ;; We can't use the optimization below because its assumptions
 434              ;; aren't always true, e.g. when completion-cycling (bug#10850):
 435              ;; (if (eq t (compare-strings (car comps) nil (length most)
 436              ;;                          most nil nil completion-ignore-case))
 437              ;;     ;; Common case.
 438              ;;     (length most)
 439              ;; Else, use try-completion.
 440              (prefix (when icomplete-hide-common-prefix
 441                        (try-completion "" comps)))
 442              (prefix-len
 443               (and (stringp prefix)
 444                    ;; Only hide the prefix if the corresponding info
 445                    ;; is already displayed via `most'.
 446                    (string-prefix-p prefix most t)
 447                    (length prefix))) ;;)
 448              prospects comp limit)
 449         (if (or (eq most-try t) (not (consp (cdr comps))))
 450             (setq prospects nil)
 451           (when (member name comps)
 452             ;; NAME is complete but not unique.  This scenario poses
 453             ;; following UI issues:
 454             ;;
 455             ;; - When `icomplete-hide-common-prefix' is non-nil, NAME
 456             ;;   is stripped empty.  This would make the entry
 457             ;;   inconspicuous.
 458             ;;
 459             ;; - Due to sorting of completions, NAME may not be the
 460             ;;   first of the prospects and could be hidden deep in
 461             ;;   the displayed string.
 462             ;;
 463             ;; - Because of `icomplete-prospects-height' , NAME may
 464             ;;   not even be displayed to the user.
 465             ;;
 466             ;; To circumvent all the above problems, provide a visual
 467             ;; cue to the user via an "empty string" in the try
 468             ;; completion field.
 469             (setq determ (concat open-bracket "" close-bracket)))
 470           ;; Compute prospects for display.
 471           (while (and comps (not limit))
 472             (setq comp
 473                   (if prefix-len (substring (car comps) prefix-len) (car comps))
 474                   comps (cdr comps))
 475             (setq prospects-len
 476                            (+ (string-width comp)
 477                               (string-width icomplete-separator)
 478                               prospects-len))
 479                      (if (< prospects-len prospects-max)
 480                          (push comp prospects)
 481               (setq limit t))))
 482         (setq prospects (nreverse prospects))
 483         ;; Decorate first of the prospects.
 484         (when prospects
 485           (let ((first (copy-sequence (pop prospects))))
 486             (put-text-property 0 (length first)
 487                                'face 'icomplete-first-match first)
 488             (push first prospects)))
 489         ;; Restore the base-size info, since completion-all-sorted-completions
 490         ;; is cached.
 491         (if last (setcdr last base-size))
 492         (if prospects
 493             (concat determ
 494                     "{"
 495                     (mapconcat 'identity prospects icomplete-separator)
 496                     (and limit (concat icomplete-separator ellipsis))
 497                     "}")
 498           (concat determ " [Matched]"))))))
 499
 500 ;;; Iswitchb compatibility
 501
 502 ;; We moved Iswitchb to `obsolete' in 24.4, but autoloads in files in
 503 ;; `obsolete' aren't obeyed (since that would encourage people to keep using
 504 ;; those packages, oblivious to their obsolescence).  Given the fact that
 505 ;; Iswitchb was very popular, we decided to keep its autoload for a bit longer,
 506 ;; so we moved it here.
 507
 508 ;;;###autoload(when (locate-library "obsolete/iswitchb")
 509 ;;;###autoload  (autoload 'iswitchb-mode "iswitchb" "Toggle Iswitchb mode." t)
 510 ;;;###autoload  (make-obsolete 'iswitchb-mode
 511 ;;;###autoload    "use `icomplete-mode' or `ido-mode' instead." "24.4"))
 512
 513 ;;;_* Provide
 514 (provide 'icomplete)
 515
 516 ;;_* Local emacs vars.
 517 ;;Local variables:
 518 ;;allout-layout: (-2 :)
 519 ;;End:
 520
 521 ;;; icomplete.el ends here