never use `eval' (was: Re: How to mapcar or across a list?)

[Emanuel Berg <embe8573@student.uu.se>]

"Pascal J. Bourguignon" <pjb@informatimago.com>
writes:

> It's always a bad idea to use eval, because eval
> evalutes in the nil environment, not in the local
> lexical envrionment.

I have used `eval' eight times in my current setup of
75 files.

Tho some of this code I wrote several years ago, I'd
be happy to correct it. Any hints - general or
specific - are appreciated.

;; From: http://user.it.uu.se/~embe8573/conf/emacs-init/faces.el

(defun set-color-face (name front &optional bold back)
  (eval `(defvar ,(make-symbol name)))
  (eval `(setq ,(intern name)
               `((t (:foreground ,front
                     :background ,back
                     :bold       ,bold) )))))

(defvar cf-black)   (set-color-face "cf-black"   "black")
(defvar cf-red)     (set-color-face "cf-red"     "red")
;; ...

;; From: http://user.it.uu.se/~embe8573/conf/emacs-init/ide/lisp.el

(defun do-repeat-complex-command ()
  (interactive)
  (eval (car command-history) ))

;; From: http://user.it.uu.se/~embe8573/conf/emacs-init/isbn.el

(defun book-page-to-bibtex ()
  (interactive)
  (save-excursion
    (goto-char (point-min))
    (let ((title (get-title))
          (data  (mapcar 'key-value
                         '("authors?" "publisher" "published" "isbn-10")) ))
      (eval `(create-book nil ,title ,@data) )))) ; don't INSERT

;; From: http://user.it.uu.se/~embe8573/conf/emacs-init/match-data-format.el

(defun match-data-format (data match format-str)
  (save-match-data
    (string-match match data)
    (eval `(message format-str ,@(make-match-list 1 data) ))))

;; From: http://user.it.uu.se/~embe8573/conf/emacs-init/wrap-search.el

(defun wrap-search-again (prefix)
  "Search again for the most recent search string of `wrap-search'.
Use \\[universal-argument] \(to set the PREFIX\) to toggle case sensitiveness."
  (interactive "p")
  (let ((cmd (cl-dolist (cmd command-history)
               (if (and (eq (car cmd) 'wrap-search)
                        (not (string= (cl-caddr cmd) "")) )
                   (cl-return cmd) ))))
    (if cmd
        (if (eq prefix 4)
            (let*((old-prefix (cadr  cmd))
                  (search-str (cl-caddr cmd))
                  (new-prefix (if (eq old-prefix 4) 1 4))
                  (final-cmd  `(wrap-search ,new-prefix ,search-str)) )
              (setq command-history (cons final-cmd command-history))
              (eval final-cmd) )
          (eval cmd) )
      (message " No previous search.") )))

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