Programming challenge: wildcard exclusion in cartesian products

[Mark Carter]

Mark Tarver wrote:
> Interesting.

At the risk of being labelled a troll, one thought that is occuring to 
me is that in Lisp it seems that sometimes it is difficult to achieve a 
simple thing in a simple way.  To clarify ... recently, I had been 
trying to obtain md5 hashes of the files we had on our server (a 
different exercise than the one I mentioned in my OP, just in case you 
thought that I didn't understand the difference between encryption and 
hashing). There is an md5 package for Lisp available on the web, which I 
used with CLISP. I had a file that contained a non-standard character, 
causing CLISP to throw an error when it tried to print it.

Well, I suppose I could have tried to figure out a way to cajole CLISP 
into printing something it didn't want to print, but I was keen to give 
Corman Lisp 2.5 a try-out anyway, so I tried the package on it. EXCEPT, 
for some reason when you try to read a file with an :element-type  of 
(unsigned-byte 8) (or something similar), Corman didn't like it.

In the end, I hacked together an md5 DLL from some sources I found on 
the internet. You can get the package here, together with Corman Lisp 
bindings:
http://www.markcarter.me.uk/computing/freeware/md5mc/md5mc.htm

In the past, I had also employed a similar technique in order to get 
access to some console functions that I was interested in.

My worry is that it seems to be a recurring theme with me ... get 
stumped in Lisp, realise that it is probably just plain easier in C, and 
then link the whole thing together in Lisp. Which is kinda less than 
expected.