elementary lisp variable == string

[SL Baur]

On Thu, Mar 12, 2009 at 10:46 AM, Uwe Brauer <oub at mat.ucm.es> wrote:
>>>>>> "Sean" == Sean MacLennan <seanm at seanm.ca> writes:
>
>   > On Thu, 12 Mar 2009 17:05:43 +0100
>   > Uwe Brauer <oub at mat.ucm.es> wrote:
>
>   >> Now in a function I want to execute certain code
>   >>
>   >> -  if isp is indeed the string "hallo" and
>   >>
>   >> -  if isp is the string  "test"  then another part of the code
>   >> will be executed.
>
>   > string= is your friend!
>  (defvar isp "hallo" )
>
>   > (if (string= isp "hallo") (message "hallo"))
>
> I presumed it would be simple, but this simple!
> Thanks

He said "simple".  Heh, heh, heh, heh.  `string=' is
typed.  To be completely defensive against users
who will (setq isp 3.1415926) ; Happy National PI Day!
you need a guard as in:
(when (and (stringp isp) (string= isp "hallo"))
  (message "hallo"))

-sb