Re: How to avoid compiler warning `unused lexical variable' for `dolist' or `dotimes'?

[Emanuel Berg]

Jean Louis wrote:

> (defun db/table-id-plist (table id pg)
>   "Returns plist for table by its table_id"
>   (let* ((columns (db/table-columns table pg))
>        (sql (db/sql-by-columns table columns id))
>        (values (rcd-sql-first sql pg))
>        (values (append values nil))
>        (length (length columns))
>        (plist '()))
>     (dotimes (i length plist)
>       (setf plist (plist-put plist (intern (elt columns i)) (elt values 
> i))))))
>
> What is proper way to avoid this warning in `dolist' or
> `dotimes':
>
> rcd-db.el:841:1: Warning: Unused lexical variable ‘i’
>
> Declaring variable `i' in `let' before `dolist' or `dotimes'
> did not help.

Right. Let's just say it is a `dotimes' thing, see line
309-310, /usr/local/share/emacs/28.0.50/lisp/subr.el

  ;; FIXME: This let often leads to "unused var" warnings.
  `((let ((,(car spec) ,counter)) ,@(cddr spec))))))

(require 'cl-lib)

(defun db/table-id-plist (table id pg)
  "Do something with TABLE, ID and PG."
  (let*((cols   (db/table-columns table pg))
        (sql    (db/sql-by-columns table cols id))
        (vals   (rcd-sql-first sql pg))
        (plist) )
    (cl-loop for c in cols
             for v in vals
             do (setf plist (plist-put plist (intern c) v)) )))

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