() Nala Ginrut <nalaginrut@gmail.com>
() Mon, 01 Apr 2013 12:00:01 +0800

   (define (str* str n)
     (format #f "~{~a~}" (make-list n str)))

   (define (str* str n)
     (string-join (make-list n str) ""))

Here's another implementation, using SRFI 13 ‘xsubstring’:

(define (str* str n)
  (xsubstring str 0 (* n (string-length str))))

I wonder how it fares.

-- 
Thien-Thi Nguyen
GPG key: 4C807502