(module util (curry applied thunk just perhaps)
  (import scheme)

  (define (curry fn a)
  (lambda (b)
    (fn a b)))

  (define (applied fn)
    (curry apply fn))
  
  (define-syntax thunk
    (syntax-rules ()
      ((_ exp ...)
       (lambda () exp ...))))
  
(define (just fn)
  (lambda args
    (fn)))

(define (perhaps fn arg)
  (if arg
      (fn arg)
      arg)))