re-rand is a Clojure library for generating random strings from regular expressions.
=> (use 're-rand)
=> (re-rand #"[A-Z]{4}")
"UTFR"
=> (re-rand #".+:\d+")
"s9QziMg1:85592"
=> (re-rand #"[^0-9][0-9]")
"i2"
=> (re-rand #"b(an)+a")
["bananananananana" "an"]