-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sat, Nov 07, 2015 at 01:58:48PM +0100, Atticus wrote: > So I wanted to try out gnu guix and thus make myself more familiar with > guile first. While running some tests I encountered a problem/bug with eq?: > > $ guile -v > guile (GNU Guile) 2.1.1 > > $ guile > scheme@(guile-user)> > (define (multirember a lat) > (cond > ((null? lat) '()) > ((eq? (car lat) a) (multirember a (cdr lat))) > (else (cons (car lat) (multirember a (cdr lat)))))) > > scheme@(guile-user)> (multirember '(a b) '(x y (a b) z (a b))) > $1 = (x y z) > > So why does guile return (x y z)? I expected (x y (a b) z (a b)). I know > eq? should only be used with symbols (and thus this example is more > theoretical) but nevertheless the return value is not right, since (eq? > '(a b) '(a b)) returns #f (Btw same in guile 2.0.11).
Hm. As far as I know (eq? '(a b) '(a b)) is not *guaranteed* to evaluate to #f. The implementation might be free to re-use things it "knows" to be constant (I might be wrong, though). Regards - -- t -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAlY/IpsACgkQBcgs9XrR2kZMoACZAc49Kzq9JzteJovmzRpH2WLv M3YAnibf8NUd5bspCqCP2cQiAWNSiREt =O1dE -----END PGP SIGNATURE-----
