1 665c255d 2023-08-04 jrmu (define (test-case actual expected)
 2 665c255d 2023-08-04 jrmu   (newline)
 3 665c255d 2023-08-04 jrmu   (display "Actual:   ")
 4 665c255d 2023-08-04 jrmu   (display actual)
 5 665c255d 2023-08-04 jrmu   (newline)
 6 665c255d 2023-08-04 jrmu   (display "Expected: ")
 7 665c255d 2023-08-04 jrmu   (display expected)
 8 665c255d 2023-08-04 jrmu   (newline))
 9 665c255d 2023-08-04 jrmu 
10 665c255d 2023-08-04 jrmu ;; (+ (* 2 1)
11 665c255d 2023-08-04 jrmu ;;    0)
12 665c255d 2023-08-04 jrmu ;; (+ (* 2 (+ (* 2 1)
13 665c255d 2023-08-04 jrmu ;; 	   0))
14 665c255d 2023-08-04 jrmu ;;    5)
15 665c255d 2023-08-04 jrmu ;; (+ (* 2 (+ (* 2 (+ (* 2 1)
16 665c255d 2023-08-04 jrmu ;; 		   0))
17 665c255d 2023-08-04 jrmu ;; 	   5))
18 665c255d 2023-08-04 jrmu ;;    0)
19 665c255d 2023-08-04 jrmu ;; (+ (* 2 (+ (* 2 (+ (* 2 (+ (* 2 1)
20 665c255d 2023-08-04 jrmu ;; 			   0))
21 665c255d 2023-08-04 jrmu ;; 		   5))
22 665c255d 2023-08-04 jrmu ;; 	   0))
23 665c255d 2023-08-04 jrmu ;;    3)
24 665c255d 2023-08-04 jrmu ;; (+ (* 2 (+ (* 2 (+ (* 2 (+ (* 2 (+ (* 2 1)
25 665c255d 2023-08-04 jrmu ;; 				   0))
26 665c255d 2023-08-04 jrmu ;; 			   5))
27 665c255d 2023-08-04 jrmu ;; 		   0))
28 665c255d 2023-08-04 jrmu ;; 	   3))
29 665c255d 2023-08-04 jrmu ;;    1)
30 665c255d 2023-08-04 jrmu 
31 665c255d 2023-08-04 jrmu ;; the pattern sort of looks like this in pseudo-code
32 665c255d 2023-08-04 jrmu ;; (+ (* 2 (horner-eval 2 (cdr coefficient-sequence)))
33 665c255d 2023-08-04 jrmu ;;    (car coefficient-sequence))
34 665c255d 2023-08-04 jrmu 
35 665c255d 2023-08-04 jrmu (define (accumulate op initial sequence)
36 665c255d 2023-08-04 jrmu   (if (null? sequence)
37 665c255d 2023-08-04 jrmu       initial
38 665c255d 2023-08-04 jrmu       (op (car sequence)
39 665c255d 2023-08-04 jrmu 	  (accumulate op initial (cdr sequence)))))
40 665c255d 2023-08-04 jrmu 
41 665c255d 2023-08-04 jrmu (define (horner-eval x coefficient-sequence)
42 665c255d 2023-08-04 jrmu   (accumulate (lambda (coefficient remaining-horner) 
43 665c255d 2023-08-04 jrmu 		(+ coefficient
44 665c255d 2023-08-04 jrmu 		   (* x remaining-horner)))
45 665c255d 2023-08-04 jrmu 	      0
46 665c255d 2023-08-04 jrmu 	      coefficient-sequence))
47 665c255d 2023-08-04 jrmu 
48 665c255d 2023-08-04 jrmu (test-case (horner-eval 0 '()) 0)
49 665c255d 2023-08-04 jrmu (test-case (horner-eval 10 '()) 0)
50 665c255d 2023-08-04 jrmu (test-case (horner-eval 0 '(1)) 1)
51 665c255d 2023-08-04 jrmu (test-case (horner-eval 2 '(1 3 0 5 0 1)) 79)
52 665c255d 2023-08-04 jrmu (test-case (horner-eval -1 '(2 4 1 1 8 3)) 3)
53 665c255d 2023-08-04 jrmu (test-case (horner-eval 1.23 '(3 5 2 9 4)) 38.079068639999996)
54 665c255d 2023-08-04 jrmu