Welcome to the CHICKEN Scheme pasting service

(define (alpha? str)
  (irregex-match '(* alpha) str))

(define (num? str)
  (irregex-match '(* num) str))

(define (alphanum? str)
  (irregex-match '(* alphanum) str))

(define ((max-length len) str)
  (>= len (string-length str)))

(define workers-table
`((name "workers_data")
  (alias "workers")
  (fields (id (type integer)
              (primary-key))
          (name (type text)
                (validators alpha?
                            (max-length 30)))
          (profession (type text)
                      (validators (max-length 50)))))