Re: defvar inside let-binding

[Stefan Monnier]

>> Yes.  Tho the "next" step you suggested (to cause defvar to change the
>> outer let-binding) will require another such function and will make
>> symbol-let-bound-p unneeded.

> Let's see...

>   ;; Use defvar to set the docstring as well as the special-variable-p flag.
>   ;; FIXME: We should reproduce more of `defvar's behavior, such as the 
> warning
>   ;; when the var is currently let-bound.
>   (if (not (default-boundp symbol))
>       ;; Don't use defvar to avoid setting a default-value when undesired.
>       (when doc (put symbol 'variable-documentation doc))
>     (eval `(defvar ,symbol nil ,@(when doc (list doc)))))

> So what I would do here now would be to add

> (when (symbol-let-bound-p symbol)
>   (message "Warning: let-bound etc"))

> now, and in Emacs 24.2, I'd change that to

> (when (symbol-let-bound-p symbol)
>   (change-outer-let-binding symbol default))

> Or something along those lines?  

Yes, although the above code is run after the var has been set,
i.e. too late.


        Stefan