Re: defvars at compile time

[Kevin Rodgers]

Katsumi Yamaoka wrote:
> > > > > > In <address@hidden> Bill Wohler wrote:
>
>
> > Reiner Steib <address@hidden> wrote:
>
>
> > > (let* ((load-path (image-load-path-for-library "mh-e" "mh-logo.xpm"))
> > >       (image-load-path (cons (car load-path)
> > >                               (when (boundp 'image-load-path)
> > >                                 image-load-path))))
> > >  (mh-tool-bar-folder-buttons-init))
>
>
> > How would you fix this, then?
>
>
> >    While compiling mh-folder-mode in file
> >    /usr/local/src/mh-e/src/emacs/lisp/mh-e/mh-folder.el:
> >      ** reference to free variable image-load-path
>
>
> I usually do this:
>
>   (when (boundp 'image-load-path)
>     (symbol-value 'image-load-path))

Would using this also quiet the compiler?

(defmacro symbol-value-safe (symbol)
  "Return SYMBOL's value, but avoid signaling an error if it is void.
If SYMBOL is void, return nil."
  (let ((temp-symbol (make-symbol "temp-symbol")))
    `(let ((,temp-symbol ,symbol))
       (if (boundp ,temp-symbol)
           (symbol-value ,temp-symbol)))))

(macroexpand '(symbol-value-safe 'image-load-path))
=>
(let ((temp-symbol (quote image-load-path)))
  (if (boundp temp-symbol) (symbol-value temp-symbol)))

--
Kevin Rodgers