Re: About `funcall'

[Raffaele Ricciardi <rfflrccrd@gmail.com>]

On 04/03/13 12:52, Xue Fuqiao wrote:
> In `yank-pop', there is an sexp about `funcall':
>
>    (funcall (or yank-undo-function 'delete-region) (point) (mark t))
>
> IIRC the first argument for `funcall' should be a function, so I'm
> confused with this usage.  Can somebody explain it to me?  Thanks.
>

(or yank-undo-function 'delete-region)

evaluates to a function, which is either the value of yank-undo-function 
or 'delete-region. Compare for instance this snippet, where `add' is a 
variable whose value is the function '+:

(let ((add '+))
   ;; Add if yes, otherwise multiply.
   (funcall (if (yes-or-no-p "Add?") add '*) 4 4))