A simple form of this procedure could be:
(define (repl-display-prompt module) (let ((p (current-error-port))) (format p "~A> " (module-name module)) (flush p)))
Repl-display-result is called by the interactive toplevel loop after the evaluation of a sexpr. This procedure is called with the result of this evaluation as parameter.
A simple form, mimicking the MIT Scheme way of presenting results, could be:
(define (repl-display-result value) (format #t "\\n;Value: ~S\\n\\n" value))