#lang scheme
(define (test-it value)
  (match value        
    [(regexp #rx"aaa") "wanna"]
    [(regexp #rx"bbb") "be"]
    [(regexp #rx"ccc") "startin"]
    [_ "somethin"]))

(for ([str '("testaaa" "testbbb" "testccc" "testddd")]) 
  (printf "~a~n" (test-it str)))