(string-read-regex! string regex flags) -> string or #f
Given a string, destructively match a regex against it. This is useful for iterative matching.
>> (define wr (make-regex "[a-z]+")) :: [regex 547210] >> (define str "alpha beta") :: "alpha beta" >> (string-read-regex! str wr) :: "alpha" >> (string-read-regex! str wr) :: "beta" >> (string-read-regex! str wr) :: #f