Symbols in interactive user input

Symbols in interactive user input

[Heime via Users list for the GNU Emacs text editor]

Do user input commands allow using symbols rather than strings?
For instance using 'extended, 'disable, 'tabtrail, which are then
used in a pcase or cond conditionals.

  (interactive
    (let* ( (colw (read-number "Line Column: " 72))
            (cseq '("extended" "disable" "tabtrail"))
            (rsel (completing-read "Selector: " cseq nil t "tabtrail"))
            (scope (completing-read "Scope: "
                     '("global" "local") nil t "local")) )

      ;; Pass a single list as argument
      (list (list colw rsel scope))) )

Re: Symbols in interactive user input

[Stephen Berman]

On Thu, 28 Nov 2024 12:13:53 +0000 Heime via Users list for the GNU Emacs text editor <help-gnu-emacs@gnu.org> wrote:

> Do user input commands allow using symbols rather than strings?
> For instance using 'extended, 'disable, 'tabtrail, which are then
> used in a pcase or cond conditionals.
>
>   (interactive
>     (let* ( (colw (read-number "Line Column: " 72))
>             (cseq '("extended" "disable" "tabtrail"))
>             (rsel (completing-read "Selector: " cseq nil t "tabtrail"))
>             (scope (completing-read "Scope: "
>                      '("global" "local") nil t "local")) )
>
>       ;; Pass a single list as argument
>       (list (list colw rsel scope))) )

`completing-read' returns a string, even if the completion collection
consists of symbols.  But you can use `intern' to get the symbol from
the string (which is the symbol's name):

(let ((s (completing-read "Enter: " '(bla bli blu) nil t)))
  (list (stringp s) (symbolp s) (symbolp (intern s))))
=> (t nil t)

Steve Berman