Re: case behaviour

[Jim White <jim at pagesmiths dot com>]

Charles Duffy wrote:
> I'm somewhat confused at the behaviour of case in kawa. Might someone be
> so kind as to explain the following behaviour, and perhaps suggest a
> workaround?
>
> (let ((foo (as <string> "quux")))
>   (case foo (("quux") "good")
>             (else "bad")))
> => good
>
> (let ((foo (make <string> "quux")))
>   (case foo (("quux") "good")
>             (else "bad")))
> => bad
The case conditional uses eqv? for testing, which will only be true for 
strings if they are the same object (eq?), not simply equivalent.

http://www.schemers.org/Documents/Standards/R5RS/HTML/r5rs-Z-H-7.html#%_sec_4.2.1

You could use cond with string=? or equal?, assoc, case with (interned) 
symbols, and no doubt a number of more ways (patterns matcher?).

(let ((foo (make-symbol "quux")))
  (case foo ((quux) "good")
            (else "bad")))

jim