Function: help-fns--describe-function-or-command-prompt

help-fns--describe-function-or-command-prompt is a byte-compiled function defined in help-fns.el.gz.

Signature

(help-fns--describe-function-or-command-prompt &optional WANT-COMMAND)

Documentation

Prompt for a function from describe-function or describe-command.

If optional argument WANT-COMMAND is non-nil, prompt for an interactive command.

Source Code

;; Defined in /usr/src/emacs/lisp/help-fns.el.gz
(defun help-fns--describe-function-or-command-prompt (&optional want-command)
  "Prompt for a function from `describe-function' or `describe-command'.
If optional argument WANT-COMMAND is non-nil, prompt for an
interactive command."
  (let* ((fn (if want-command
                 (caar command-history)
               (function-called-at-point)))
         (prompt (format-prompt (if want-command
                                    "Describe command"
                                  "Describe function")
                                fn))
         (enable-recursive-minibuffers t)
         (val (completing-read
               prompt
               #'help--symbol-completion-table
               (lambda (f) (if want-command
                          (commandp f)
                        (or (fboundp f) (get f 'function-documentation))))
               ;; We used `confirm' for a while because we may want to see the
               ;; meta-info about a function even if the function itself is not
               ;; defined, but this use case is too marginal and rarely tested,
               ;; not worth the trouble (bug#64902).
               t nil nil
               (and fn (symbol-name fn)))))
    (unless (equal val "")
      (setq fn (intern val)))
    ;; These error messages are intended to be less technical for the
    ;; `describe-command' case, as they are directed at users that are
    ;; not necessarily ELisp programmers.
    (unless (and fn (symbolp fn))
      (user-error (if want-command
                      "You didn't specify a command's symbol"
                    "You didn't specify a function symbol")))
    (unless (or (fboundp fn) (get fn 'function-documentation))
      (user-error (if want-command
                      "Symbol is not a command: %s"
                    "Symbol's function definition is void: %s")
                  fn))
    (list fn)))