Who's minister of propaganda this week?

[Graham Hughes]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

>>>>> "Don" == Don Dwiggins <dwig at advancedmp.net> writes:

    Don> Alex Martelli writes:
    >> Another way to express it: an interface is not just, not even
    >> _mostly_, about existence and signature of methods -- it's
    >> mostly about prereq's, post-conditions, and invariants; and
    >> nobody can check those at compile-time in enough cases to make
    >> a difference to your software's reliability.

    Don> I agree whole-heartedly with the first clause, but I wonder:
    Don> if you made the same statement over on comp.lang.eiffel, what
    Don> kind of response would you get from folks who use the
    Don> language extensively?  Are Eiffel's prereq's,
    Don> post-conditions, and invariants mostly ignored in practice,
    Don> or are they commonly and effectively used?

They are run time--Alex is talking about compile time.  I'm not aware
of anyone who has a compiler that can check that the output of sqrt
times itself is the input.
- -- 
Graham Hughes <ghughes at lynda.com>
(defun whee (n e) (subseq (let ((c (cons e e))) (nconc c c)) 0 n))
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.4 (GNU/Linux)
Comment: Processed by Mailcrypt 3.5.5 and Gnu Privacy Guard <http://www.gnupg.org/>

iD8DBQE6saHo8i4DkPg349kRAn3JAJ9Tru1pnnFnulnqdsqt1G+MHjLdKACeLW4A
h9tVYwUkF+C2FcLVqSJIqbg=
=Kgjo
-----END PGP SIGNATURE-----