You wouldn't write it like this, but you could: def (pair? (x | (first ... (rest | (second ... rest2)))))
(and list?.x
list?.rest
no.rest2)
I'm currently not using as-patterns for pattern matching, just destructuring: def (copy (x | (head ... tail)))
if (~bound? 'head) # enter even if x is not a list
x
(cons copy.head copy.tail)
I'm not sure how useful this is; every use case I've seen for it seems worse than just using car and cdr. Thoughts?P.S. Building this feature turned out to be shockingly easy: http://github.com/akkartik/wart/commit/90646d3980 | 
