config

Personal configuration.
git clone git://code.dwrz.net/config
Log | Files | Refs

compat-26.el (22090B)


      1 ;;; compat-26.el --- Functionality added in Emacs 26.1 -*- lexical-binding: t; -*-
      2 
      3 ;; Copyright (C) 2021-2024 Free Software Foundation, Inc.
      4 
      5 ;; This program is free software; you can redistribute it and/or modify
      6 ;; it under the terms of the GNU General Public License as published by
      7 ;; the Free Software Foundation, either version 3 of the License, or
      8 ;; (at your option) any later version.
      9 
     10 ;; This program is distributed in the hope that it will be useful,
     11 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
     12 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     13 ;; GNU General Public License for more details.
     14 
     15 ;; You should have received a copy of the GNU General Public License
     16 ;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
     17 
     18 ;;; Commentary:
     19 
     20 ;; Functionality added in Emacs 26.1, needed by older Emacs versions.
     21 
     22 ;;; Code:
     23 
     24 (eval-when-compile (load "compat-macs.el" nil t t))
     25 (compat-require compat-25 "25.1")
     26 
     27 (compat-version "26.1")
     28 
     29 ;;;; Defined in fns.c
     30 
     31 (compat-defun buffer-hash (&optional buffer-or-name) ;; <compat-tests:buffer-hash>
     32    "Return a hash of the contents of BUFFER-OR-NAME.
     33 This hash is performed on the raw internal format of the buffer,
     34 disregarding any coding systems.  If nil, use the current buffer.
     35 
     36 This function is useful for comparing two buffers running in the same
     37 Emacs, but is not guaranteed to return the same hash between different
     38 Emacs versions.  It should be somewhat more efficient on larger
     39 buffers than `secure-hash' is, and should not allocate more memory.
     40 
     41 It should not be used for anything security-related.  See
     42 `secure-hash' for these applications."
     43    (with-current-buffer (or buffer-or-name (current-buffer))
     44      (save-restriction
     45        (widen)
     46        (sha1 (current-buffer) (point-min) (point-max)))))
     47 
     48 (compat-defun mapcan (func sequence) ;; <compat-tests:mapcan>
     49   "Apply FUNC to each element of SEQUENCE.
     50 Concatenate the results by altering them (using `nconc').
     51 SEQUENCE may be a list, a vector, a boolean vector, or a string."
     52   (apply #'nconc (mapcar func sequence)))
     53 
     54 (compat-defun line-number-at-pos (&optional position absolute) ;; <compat-tests:line-number-at-pos>
     55   "Handle optional argument ABSOLUTE."
     56   :extended t
     57   (if absolute
     58       (save-restriction
     59         (widen)
     60         (line-number-at-pos position))
     61     (line-number-at-pos position)))
     62 
     63 ;;;; Defined in simple.el
     64 
     65 (compat-defun region-bounds () ;; <compat-tests:region-bounds>
     66   "Return the boundaries of the region.
     67 Value is a list of one or more cons cells of the form (START . END).
     68 It will have more than one cons cell when the region is non-contiguous,
     69 see `region-noncontiguous-p' and `extract-rectangle-bounds'."
     70   (if (eval-when-compile (< emacs-major-version 25))
     71       ;; FIXME: The `region-extract-function' of Emacs 24 has no support for the
     72       ;; bounds argument.
     73       (list (cons (region-beginning) (region-end)))
     74     (funcall region-extract-function 'bounds)))
     75 
     76 ;;;; Defined in subr.el
     77 
     78 (compat-defun provided-mode-derived-p (mode &rest modes) ;; <compat-tests:provided-mode-derived-p>
     79   "Non-nil if MODE is derived from one of MODES.
     80 Uses the `derived-mode-parent' property of the symbol to trace backwards.
     81 If you just want to check `major-mode', use `derived-mode-p'."
     82   ;; If MODE is an alias, then look up the real mode function first.
     83   (let ((alias (symbol-function mode)))
     84     (when (and alias (symbolp alias))
     85       (setq mode alias)))
     86   (while
     87       (and
     88        (not (memq mode modes))
     89        (let* ((parent (get mode 'derived-mode-parent))
     90               (parentfn (symbol-function parent)))
     91          (setq mode (if (and parentfn (symbolp parentfn)) parentfn parent)))))
     92   mode)
     93 
     94 (compat-defun assoc (key alist &optional testfn) ;; <compat-tests:assoc>
     95   "Handle the optional TESTFN."
     96   :extended t
     97   (cond
     98    ((or (eq testfn #'eq)
     99         (and (not testfn) (or (symbolp key) (integerp key)))) ;; eq_comparable_value
    100     (assq key alist))
    101    ((or (eq testfn #'equal) (not testfn))
    102     (assoc key alist))
    103    (t
    104     (catch 'found
    105       (dolist (ent alist)
    106         (when (funcall testfn (car ent) key)
    107           (throw 'found ent)))))))
    108 
    109 (compat-defun alist-get (key alist &optional default remove testfn) ;; <compat-tests:alist-get>
    110   "Handle optional argument TESTFN."
    111   :extended "25.1"
    112   (ignore remove)
    113   (let ((x (if (not testfn)
    114                (assq key alist)
    115              (compat--assoc key alist testfn))))
    116     (if x (cdr x) default)))
    117 
    118 (compat-guard t ;; <compat-tests:alist-get-gv>
    119   (gv-define-expander compat--alist-get
    120     (lambda (do key alist &optional default remove testfn)
    121       (macroexp-let2 macroexp-copyable-p k key
    122         (gv-letplace (getter setter) alist
    123           (macroexp-let2 nil p `(compat--assoc ,k ,getter ,testfn)
    124             (funcall do (if (null default) `(cdr ,p)
    125                           `(if ,p (cdr ,p) ,default))
    126                      (lambda (v)
    127                        (macroexp-let2 nil v v
    128                          (let ((set-exp
    129                                 `(if ,p (setcdr ,p ,v)
    130                                    ,(funcall setter
    131                                              `(cons (setq ,p (cons ,k ,v))
    132                                                     ,getter)))))
    133                            `(progn
    134                               ,(cond
    135                                 ((null remove) set-exp)
    136                                 ((or (eql v default)
    137                                      (and (eq (car-safe v) 'quote)
    138                                           (eq (car-safe default) 'quote)
    139                                           (eql (cadr v) (cadr default))))
    140                                  `(if ,p ,(funcall setter `(delq ,p ,getter))))
    141                                 (t
    142                                  `(cond
    143                                    ((not (eql ,default ,v)) ,set-exp)
    144                                    (,p ,(funcall setter
    145                                                  `(delq ,p ,getter))))))
    146                               ,v))))))))))
    147     (unless (get 'alist-get 'gv-expander)
    148       (put 'alist-get 'gv-expander (get 'compat--alist-get 'gv-expander))))
    149 
    150 (compat-defun string-trim-left (string &optional regexp) ;; <compat-tests:string-trim-left>
    151   "Handle optional argument REGEXP."
    152   :extended t
    153   (if (string-match (concat "\\`\\(?:" (or regexp "[ \t\n\r]+") "\\)") string)
    154       (substring string (match-end 0))
    155     string))
    156 
    157 (compat-defun string-trim-right (string &optional regexp) ;; <compat-tests:string-trim-right>
    158   "Handle optional argument REGEXP."
    159   :extended t
    160   (let ((i (string-match-p
    161             (concat "\\(?:" (or regexp "[ \t\n\r]+") "\\)\\'")
    162             string)))
    163     (if i (substring string 0 i) string)))
    164 
    165 (compat-defun string-trim (string &optional trim-left trim-right) ;; <compat-tests:string-trim>
    166   "Handle optional arguments TRIM-LEFT and TRIM-RIGHT."
    167   :extended t
    168   (compat--string-trim-left
    169    (compat--string-trim-right
    170     string
    171     trim-right)
    172    trim-left))
    173 
    174 (compat-defun caaar (x) ;; <compat-tests:cXXXr>
    175   "Return the `car' of the `car' of the `car' of X."
    176   (declare (pure t))
    177   (car (car (car x))))
    178 
    179 (compat-defun caadr (x) ;; <compat-tests:cXXXr>
    180   "Return the `car' of the `car' of the `cdr' of X."
    181   (declare (pure t))
    182   (car (car (cdr x))))
    183 
    184 (compat-defun cadar (x) ;; <compat-tests:cXXXr>
    185   "Return the `car' of the `cdr' of the `car' of X."
    186   (declare (pure t))
    187   (car (cdr (car x))))
    188 
    189 (compat-defun caddr (x) ;; <compat-tests:cXXXr>
    190   "Return the `car' of the `cdr' of the `cdr' of X."
    191   (declare (pure t))
    192   (car (cdr (cdr x))))
    193 
    194 (compat-defun cdaar (x) ;; <compat-tests:cXXXr>
    195   "Return the `cdr' of the `car' of the `car' of X."
    196   (declare (pure t))
    197   (cdr (car (car x))))
    198 
    199 (compat-defun cdadr (x) ;; <compat-tests:cXXXr>
    200   "Return the `cdr' of the `car' of the `cdr' of X."
    201   (declare (pure t))
    202   (cdr (car (cdr x))))
    203 
    204 (compat-defun cddar (x) ;; <compat-tests:cXXXr>
    205   "Return the `cdr' of the `cdr' of the `car' of X."
    206   (declare (pure t))
    207   (cdr (cdr (car x))))
    208 
    209 (compat-defun cdddr (x) ;; <compat-tests:cXXXr>
    210   "Return the `cdr' of the `cdr' of the `cdr' of X."
    211   (declare (pure t))
    212   (cdr (cdr (cdr x))))
    213 
    214 (compat-defun caaaar (x) ;; <compat-tests:cXXXXr>
    215   "Return the `car' of the `car' of the `car' of the `car' of X."
    216   (declare (pure t))
    217   (car (car (car (car x)))))
    218 
    219 (compat-defun caaadr (x) ;; <compat-tests:cXXXXr>
    220   "Return the `car' of the `car' of the `car' of the `cdr' of X."
    221   (declare (pure t))
    222   (car (car (car (cdr x)))))
    223 
    224 (compat-defun caadar (x) ;; <compat-tests:cXXXXr>
    225   "Return the `car' of the `car' of the `cdr' of the `car' of X."
    226   (declare (pure t))
    227   (car (car (cdr (car x)))))
    228 
    229 (compat-defun caaddr (x) ;; <compat-tests:cXXXXr>
    230   "Return the `car' of the `car' of the `cdr' of the `cdr' of X."
    231   (declare (pure t))
    232   (car (car (cdr (cdr x)))))
    233 
    234 (compat-defun cadaar (x) ;; <compat-tests:cXXXXr>
    235   "Return the `car' of the `cdr' of the `car' of the `car' of X."
    236   (declare (pure t))
    237   (car (cdr (car (car x)))))
    238 
    239 (compat-defun cadadr (x) ;; <compat-tests:cXXXXr>
    240   "Return the `car' of the `cdr' of the `car' of the `cdr' of X."
    241   (declare (pure t))
    242   (car (cdr (car (cdr x)))))
    243 
    244 (compat-defun caddar (x) ;; <compat-tests:cXXXXr>
    245   "Return the `car' of the `cdr' of the `cdr' of the `car' of X."
    246   (declare (pure t))
    247   (car (cdr (cdr (car x)))))
    248 
    249 (compat-defun cadddr (x) ;; <compat-tests:cXXXXr>
    250   "Return the `car' of the `cdr' of the `cdr' of the `cdr' of X."
    251   (declare (pure t))
    252   (car (cdr (cdr (cdr x)))))
    253 
    254 (compat-defun cdaaar (x) ;; <compat-tests:cXXXXr>
    255   "Return the `cdr' of the `car' of the `car' of the `car' of X."
    256   (declare (pure t))
    257   (cdr (car (car (car x)))))
    258 
    259 (compat-defun cdaadr (x) ;; <compat-tests:cXXXXr>
    260   "Return the `cdr' of the `car' of the `car' of the `cdr' of X."
    261   (declare (pure t))
    262   (cdr (car (car (cdr x)))))
    263 
    264 (compat-defun cdadar (x) ;; <compat-tests:cXXXXr>
    265   "Return the `cdr' of the `car' of the `cdr' of the `car' of X."
    266   (declare (pure t))
    267   (cdr (car (cdr (car x)))))
    268 
    269 (compat-defun cdaddr (x) ;; <compat-tests:cXXXXr>
    270   "Return the `cdr' of the `car' of the `cdr' of the `cdr' of X."
    271   (declare (pure t))
    272   (cdr (car (cdr (cdr x)))))
    273 
    274 (compat-defun cddaar (x) ;; <compat-tests:cXXXXr>
    275   "Return the `cdr' of the `cdr' of the `car' of the `car' of X."
    276   (declare (pure t))
    277   (cdr (cdr (car (car x)))))
    278 
    279 (compat-defun cddadr (x) ;; <compat-tests:cXXXXr>
    280   "Return the `cdr' of the `cdr' of the `car' of the `cdr' of X."
    281   (declare (pure t))
    282   (cdr (cdr (car (cdr x)))))
    283 
    284 (compat-defun cdddar (x) ;; <compat-tests:cXXXXr>
    285   "Return the `cdr' of the `cdr' of the `cdr' of the `car' of X."
    286   (declare (pure t))
    287   (cdr (cdr (cdr (car x)))))
    288 
    289 (compat-defun cddddr (x) ;; <compat-tests:cXXXXr>
    290   "Return the `cdr' of the `cdr' of the `cdr' of the `cdr' of X."
    291   (declare (pure t))
    292   (cdr (cdr (cdr (cdr x)))))
    293 
    294 (compat-defvar gensym-counter 0 ;; <compat-tests:gensym>
    295   "Number used to construct the name of the next symbol created by `gensym'.")
    296 
    297 (compat-defun gensym (&optional prefix) ;; <compat-tests:gensym>
    298   "Return a new uninterned symbol.
    299 The name is made by appending `gensym-counter' to PREFIX.
    300 PREFIX is a string, and defaults to \"g\"."
    301   (let ((num (prog1 gensym-counter
    302                (setq gensym-counter
    303                      (1+ gensym-counter)))))
    304     (make-symbol (format "%s%d" (or prefix "g") num))))
    305 
    306 (compat-defmacro if-let* (varlist then &rest else) ;; <compat-tests:if-let*>
    307   "Bind variables according to VARLIST and evaluate THEN or ELSE.
    308 This is like `if-let' but doesn't handle a VARLIST of the form
    309 \(SYMBOL SOMETHING) specially."
    310   (declare (indent 2)
    311            (debug ((&rest [&or symbolp (symbolp form) (form)])
    312                    body)))
    313   (let ((empty (make-symbol "s"))
    314         (last t) list)
    315     (dolist (var varlist)
    316       (push `(,(if (cdr var) (car var) empty)
    317               (and ,last ,(if (cdr var) (cadr var) (car var))))
    318             list)
    319       (when (or (cdr var) (consp (car var)))
    320         (setq last (caar list))))
    321     `(let* ,(nreverse list)
    322        (if ,(caar list) ,then ,@else))))
    323 
    324 (compat-defmacro when-let* (varlist &rest body) ;; <compat-tests:when-let*>
    325   "Bind variables according to VARLIST and conditionally evaluate BODY.
    326 This is like `when-let' but doesn't handle a VARLIST of the form
    327 \(SYMBOL SOMETHING) specially."
    328   (declare (indent 1) (debug if-let*))
    329   (list 'if-let* varlist (macroexp-progn body)))
    330 
    331 (compat-defmacro and-let* (varlist &rest body) ;; <compat-tests:and-let*>
    332   "Bind variables according to VARLIST and conditionally evaluate BODY.
    333 Like `when-let*', except if BODY is empty and all the bindings
    334 are non-nil, then the result is non-nil."
    335   (declare (indent 1)
    336            (debug ((&rest [&or symbolp (symbolp form) (form)])
    337                    body)))
    338   (let ((empty (make-symbol "s"))
    339         (last t) list)
    340     (dolist (var varlist)
    341       (push `(,(if (cdr var) (car var) empty)
    342               (and ,last ,(if (cdr var) (cadr var) (car var))))
    343             list)
    344       (when (or (cdr var) (consp (car var)))
    345         (setq last (caar list))))
    346     `(let* ,(nreverse list)
    347        (if ,(caar list) ,(macroexp-progn (or body '(t)))))))
    348 
    349 ;;;; Defined in files.el
    350 
    351 (compat-defvar mounted-file-systems ;; <compat-tests:mounted-file-systems>
    352     (eval-when-compile
    353       (if (memq system-type '(windows-nt cygwin))
    354           "^//[^/]+/"
    355         (concat
    356          "^" (regexp-opt '("/afs/" "/media/" "/mnt" "/net/" "/tmp_mnt/")))))
    357   "File systems that ought to be mounted.")
    358 
    359 (compat-defun file-local-name (file) ;; <compat-tests:file-local-name>
    360   "Return the local name component of FILE.
    361 This function removes from FILE the specification of the remote host
    362 and the method of accessing the host, leaving only the part that
    363 identifies FILE locally on the remote system.
    364 The returned file name can be used directly as argument of
    365 `process-file', `start-file-process', or `shell-command'."
    366   (or (file-remote-p file 'localname) file))
    367 
    368 (compat-defun temporary-file-directory () ;; <compat-tests:temporary-file-directory>
    369   "The directory for writing temporary files.
    370 In case of a remote `default-directory', this is a directory for
    371 temporary files on that remote host.  If such a directory does
    372 not exist, or `default-directory' ought to be located on a
    373 mounted file system (see `mounted-file-systems'), the function
    374 returns `default-directory'.
    375 For a non-remote and non-mounted `default-directory', the value of
    376 the variable `temporary-file-directory' is returned."
    377   ;; NOTE: The handler may fail with an error, since the
    378   ;; `temporary-file-directory' handler was introduced in Emacs 26.
    379   (let ((handler (find-file-name-handler
    380                   default-directory 'temporary-file-directory)))
    381     (or (and handler (ignore-errors (funcall handler 'temporary-file-directory)))
    382         (if-let ((remote (file-remote-p default-directory)))
    383             (concat remote "/tmp/") ;; FIXME: Guess /tmp on remote host
    384           (if (string-match mounted-file-systems default-directory)
    385               default-directory
    386             temporary-file-directory)))))
    387 
    388 (compat-defun make-temp-file (prefix &optional dir-flag suffix text) ;; <compat-tests:make-temp-file>
    389   "Handle optional argument TEXT."
    390   :extended t
    391   (let ((file (make-temp-file prefix dir-flag suffix)))
    392     (when text
    393       (with-temp-buffer
    394         (insert text)
    395         (write-region (point-min) (point-max) file)))
    396     file))
    397 
    398 (compat-defun make-nearby-temp-file (prefix &optional dir-flag suffix) ;; <compat-tests:make-nearby-temp-file>
    399   "Create a temporary file as close as possible to `default-directory'.
    400 If PREFIX is a relative file name, and `default-directory' is a
    401 remote file name or located on a mounted file systems, the
    402 temporary file is created in the directory returned by the
    403 function `temporary-file-directory'.  Otherwise, the function
    404 `make-temp-file' is used.  PREFIX, DIR-FLAG and SUFFIX have the
    405 same meaning as in `make-temp-file'."
    406   ;; NOTE: The handler may fail with an error, since the
    407   ;; `make-nearby-temp-file' handler was introduced in Emacs 26.
    408   (let ((handler (and (not (file-name-absolute-p default-directory))
    409                       (find-file-name-handler
    410                        default-directory 'make-nearby-temp-file))))
    411     (or (and handler (ignore-errors (funcall handler 'make-nearby-temp-file
    412                                              prefix dir-flag suffix)))
    413         (let ((temporary-file-directory (temporary-file-directory)))
    414           (make-temp-file prefix dir-flag suffix)))))
    415 
    416 (compat-defun file-attribute-type (attributes) ;; <compat-tests:file-attribute-getters>
    417   "The type field in ATTRIBUTES returned by `file-attributes'.
    418 The value is either t for directory, string (name linked to) for
    419 symbolic link, or nil."
    420   (nth 0 attributes))
    421 
    422 (compat-defun file-attribute-link-number (attributes) ;; <compat-tests:file-attribute-getters>
    423   "Return the number of links in ATTRIBUTES returned by `file-attributes'."
    424   (nth 1 attributes))
    425 
    426 (compat-defun file-attribute-user-id (attributes) ;; <compat-tests:file-attribute-getters>
    427   "The UID field in ATTRIBUTES returned by `file-attributes'.
    428 This is either a string or a number.  If a string value cannot be
    429 looked up, a numeric value, either an integer or a float, is
    430 returned."
    431   (nth 2 attributes))
    432 
    433 (compat-defun file-attribute-group-id (attributes) ;; <compat-tests:file-attribute-getters>
    434   "The GID field in ATTRIBUTES returned by `file-attributes'.
    435 This is either a string or a number.  If a string value cannot be
    436 looked up, a numeric value, either an integer or a float, is
    437 returned."
    438   (nth 3 attributes))
    439 
    440 (compat-defun file-attribute-access-time (attributes) ;; <compat-tests:file-attribute-getters>
    441   "The last access time in ATTRIBUTES returned by `file-attributes'.
    442 This a Lisp timestamp in the style of `current-time'."
    443   (nth 4 attributes))
    444 
    445 (compat-defun file-attribute-modification-time (attributes) ;; <compat-tests:file-attribute-getters>
    446   "The modification time in ATTRIBUTES returned by `file-attributes'.
    447 This is the time of the last change to the file's contents, and
    448 is a Lisp timestamp in the style of `current-time'."
    449   (nth 5 attributes))
    450 
    451 (compat-defun file-attribute-status-change-time (attributes) ;; <compat-tests:file-attribute-getters>
    452   "The status modification time in ATTRIBUTES returned by `file-attributes'.
    453 This is the time of last change to the file's attributes: owner
    454 and group, access mode bits, etc., and is a Lisp timestamp in the
    455 style of `current-time'."
    456   (nth 6 attributes))
    457 
    458 (compat-defun file-attribute-size (attributes) ;; <compat-tests:file-attribute-getters>
    459   "The integer size (in bytes) in ATTRIBUTES returned by `file-attributes'."
    460   (nth 7 attributes))
    461 
    462 (compat-defun file-attribute-modes (attributes) ;; <compat-tests:file-attribute-getters>
    463   "The file modes in ATTRIBUTES returned by `file-attributes'.
    464 This is a string of ten letters or dashes as in ls -l."
    465   (nth 8 attributes))
    466 
    467 (compat-defun file-attribute-inode-number (attributes) ;; <compat-tests:file-attribute-getters>
    468   "The inode number in ATTRIBUTES returned by `file-attributes'.
    469 It is a nonnegative integer."
    470   (nth 10 attributes))
    471 
    472 (compat-defun file-attribute-device-number (attributes) ;; <compat-tests:file-attribute-getters>
    473   "The file system device number in ATTRIBUTES returned by `file-attributes'.
    474 It is an integer."
    475   (nth 11 attributes))
    476 
    477 (compat-defun file-attribute-collect (attributes &rest attr-names) ;; <compat-tests:file-attribute-collect>
    478   "Return a sublist of ATTRIBUTES returned by `file-attributes'.
    479 ATTR-NAMES are symbols with the selected attribute names.
    480 
    481 Valid attribute names are: type, link-number, user-id, group-id,
    482 access-time, modification-time, status-change-time, size, modes,
    483 inode-number and device-number."
    484   (let ((idx '((type . 0)
    485                (link-number . 1)
    486                (user-id . 2)
    487                (group-id . 3)
    488                (access-time . 4)
    489                (modification-time . 5)
    490                (status-change-time . 6)
    491                (size . 7)
    492                (modes . 8)
    493                (inode-number . 10)
    494                (device-number . 11)))
    495         result)
    496     (while attr-names
    497       (let ((attr (pop attr-names)))
    498         (if (assq attr idx)
    499             (push (nth (cdr (assq attr idx))
    500                        attributes)
    501                   result)
    502           (error "Wrong attribute name '%S'" attr))))
    503     (nreverse result)))
    504 
    505 ;;;; Defined in mouse.el
    506 
    507 (compat-defvar mouse-select-region-move-to-beginning nil ;; <compat-tests:thing-at-mouse>
    508   "Effect of selecting a region extending backward from double click.
    509 Nil means keep point at the position clicked (region end);
    510 non-nil means move point to beginning of region.")
    511 
    512 ;;;; Defined in image.el
    513 
    514 (compat-defun image-property (image property) ;; <compat-tests:image-property>
    515   "Return the value of PROPERTY in IMAGE.
    516 Properties can be set with
    517 
    518   (setf (image-property IMAGE PROPERTY) VALUE)
    519 
    520 If VALUE is nil, PROPERTY is removed from IMAGE."
    521   :feature image
    522   (plist-get (cdr image) property))
    523 
    524 ;;;; Defined in rmc.el
    525 
    526 (compat-defun read-multiple-choice (prompt choices) ;; <compat-tests:read-multiple-choice>
    527   "Ask user to select an entry from CHOICES, promting with PROMPT.
    528 This function allows to ask the user a multiple-choice question.
    529 
    530 CHOICES should be a list of the form (KEY NAME [DESCRIPTION]).
    531 KEY is a character the user should type to select the entry.
    532 NAME is a short name for the entry to be displayed while prompting
    533 \(if there's no room, it might be shortened).
    534 
    535 NOTE: This is a partial implementation of `read-multiple-choice', that
    536 among other things doesn't offer any help and ignores the
    537 optional DESCRIPTION field."
    538   (let ((options
    539          (mapconcat
    540           (lambda (opt)
    541             (format
    542              "[%s] %s"
    543              (key-description (string (car opt)))
    544              (cadr opt)))
    545           choices " "))
    546         choice)
    547     (setq prompt (concat prompt " (" options "): "))
    548     (while (not (setq choice (assq (read-event prompt) choices)))
    549       (message "Invalid choice")
    550       (sit-for 1))
    551     choice))
    552 
    553 (provide 'compat-26)
    554 ;;; compat-26.el ends here