On Tue, Nov 28, 2000 at 03:34:22PM -0500, Dan Sugalski wrote:
> At 01:25 PM 11/28/00 -0600, Jarkko Hietaniemi wrote:
> >On Tue, Nov 28, 2000 at 07:03:49PM +0000, Tom Hughes wrote:
> > > Applying the maxim that any software design problem can be solved
> > > with sufficient levels of abstraction I'd suggest that passing some
> >
> >A related warning sign is trying to cram different semantic levels or
> >types into same data. (C's "string model" being perhaps the most
> >obvious example, getchar() having to be an int is another, "0 but true"
> >a third...I want a "1 but false" :-)
>
> Which ways is that one being violated? (I can think of a couple
> personally... :)
Embedding the (fixed-length) length into the data. As Nicholas points
out, that is naughty. Remember:
sizeof(char) >= sizeof(short) >= sizeof(int) >= sizeof(long)
sizeof(char) == 1
(IIRC) are the only guarantees you get. No structure alignment/padding
guarantees. Let's pick a platform that would have difficulties:
Cray C-series (nowadays called SV-series, I think). There's *no*
integer data type four bytes wide (or two bytes, for that matter).
It's either 1 (char), or 8.
--
$jhi++; # http://www.iki.fi/jhi/
# There is this special biologist word we use for 'stable'.
# It is 'dead'. -- Jack Cohen
