This is just a reminder to myself to think about extending pattern matching to regular expressions on strings. It'd be a great feature, though with the famous caveat about regular expressions. [I have a problem. I think I can solve it with regular expressions. Now I have two problems.]
(define sample
"(?P<x>[0-9]+)+(?P<y>[0-9]+)" -> (+ (string->int x) (string->int y))
"[^x]+(?P<nx>x+)[^x]+" -> (string-length nx)
)
I still remember looking through the ejabberd source code, trying to find their xml parser. When it finally dawned on me that it was automagically hidden in the pattern matching, I was impressed.