;; -- cd which has an artist, title, num-tracks, and length

;;TODO: make the struct cd



;; List-of-CD is
;; --empty
;; -- (cons CD list-of-CD)

;;TODO: create a template for List-of-CD


;; Create a function find-name that when given a list of cds and a name returns a list of all the media 
;; that has the same name
;; examples:
;; (find-name "joe" (list (make-cd "joe" "lucky" 10 50) (make-cd "joe" "b" 34) (make-cd "tom" "princess" 110))) =>
;;                 => (list (make-cd "joe" "lucky" 10 50) (make-cd "joe" "b" 23 100))






;; Create a function, sum-time, that takes a list of cd's and calculates the time to play all of them
 

 

 
 ;; Create a function, find-artists, that takes a list of cd's and returns a list of just the artists names
 


 
 
 ;; create a function, length-artist, that takes an artist and a list of cd's and returns the combined length for all
 ;;          that artists cd's

 
  


 ;; create a function, running-time, which when given a list of cd's and a number, returns only the cd's whose 
 ;; number of tracks is greater than the inputed number