Programming challenge: wildcard exclusion in cartesian products

[Mark Carter]

Mark Carter wrote:

> At the risk of being labelled a troll

One thing I just discovered, and by which I mean *really* discovered ... 
is that Lisp is an interactive environment. I am working on trying to 
verify the contents of disks. I noticed that the input formats are 
slightly wrong, and needed correction. In fact, there's a whole host of 
jiggery pokery that I need to do in order to massage and build up 
everything the way it needs to be.

A programmers mindset is usually geared towards "writing applications". 
What I'm currently doing in Lisp is building up functions as I need 
them. Using emacs, I can just C-x C-e to make my functions "live", and 
when it's time to stop for the day, save my working image so that I can 
use it the next day.

It seems to me that only Forth or Scheme really matches this capability. 
Ruby and Python come kinda close - they do have a REPL, but it's kinda 
clunky to try to create functions on the fly, plus of course they don't 
support the idea of an image.