(module zip-help mzscheme
  (require (lib "plt-match.ss")
           (lib "list.ss"))
  (provide (all-defined))
  
  (define (andmap/mi lst)
    (match lst
      [(list-rest x xs)
       (let/ec esc
         (foldl (lambda (cur last)
                  (if (module-identifier=? cur last)
                      cur
                      (esc #f)))
                x
                xs)
         #t)]
      [(list)
       #t]))
      
  (define mi-lookup
    (match-lambda*
      [(list (and q (list the-s the-f))
             (list-rest (list (list an-s an-f) uss) r))
       (if (and (module-identifier=? the-s an-s)
                (module-identifier=? the-f an-f))
           uss
           (mi-lookup q r))]))
  (define mi-insert
    (match-lambda*
      [(list (and i (list the-s the-f)) the-us (and m (list)))
       (list* (list i (list the-us)) m)]
      [(list (and i (list the-s the-f)) the-us 
             (and m (list-rest (list (and c (list an-s an-f)) a-uss) r)))
       (if (and (module-identifier=? the-s an-s)
                (module-identifier=? the-f an-f))
           (list* (list i (list* the-us a-uss)) r)
           (list* (list c a-uss) (mi-insert i the-us r)))])))