CS2613/labs/L03/first-rest-pattern.rkt

#lang slideshow

(define (my-map f lst)
  (cond
   [(empty? lst) empty]
   [else (cons (f (first lst))
               (my-map f (rest lst)))]))

(define (rainbow p)
  (map (lambda (color)
         (colorize p color))
       (list "red" "orange" "yellow" "green" "blue" "purple")))


(rainbow (circle 10))

(define (rainbow2 p)
  (define (color-mapper gr-obj color-list)
    (cond
      [(empty? color-list) empty]
      [else (cons(colorize gr-obj (first color-list))
        (color-mapper gr-obj (rest color-list)))]))
        (color-mapper p (list "red" "orange" "yellow" "green" "blue" "purple")))

(rainbow2 (circle 20))