Re: (error (format ...

[David Kastrup <dak@gnu.org>]

Juanma Barranquero <lekktu@gmail.com> writes:

> Is there any reason for uses like this one from simple.el:
>
>   (error (format "No further undo information%s"
>                (if (and transient-mark-mode mark-active)
>                    " for region" "")))
>
> instead of simply:
>
>   (error "No further undo information%s"
>          (if (and transient-mark-mode mark-active)
>              " for region" ""))

I'd probably be tempted to use

    (error (concat "No further undo information"
                   (and transient-mark-mode mark-active
                        " for region")))

in this case.  It shares the disadvantage of the original version
(when compared to yours) of being more likely to lead to accidental
format string vulnerabilities if a user takes this as starting code
for something with a variable string.

It is perhaps more educational to preferable follow (error ... with a
constant string.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum