1 665c255d 2023-08-04 jrmu (define (make-table)
 2 665c255d 2023-08-04 jrmu   (define local-table '())
 3 665c255d 2023-08-04 jrmu   (define make-record cons)
 4 665c255d 2023-08-04 jrmu   (define key-record car)
 5 665c255d 2023-08-04 jrmu   (define value-record cdr)
 6 665c255d 2023-08-04 jrmu   (define (make-tree entry left right) 
 7 665c255d 2023-08-04 jrmu     (list entry let right)) 
 8 665c255d 2023-08-04 jrmu   (define entry car)
 9 665c255d 2023-08-04 jrmu   (define left-branch cadr)
10 665c255d 2023-08-04 jrmu   (define right-branch caddr)
11 665c255d 2023-08-04 jrmu   (define key=? equal?)
12 665c255d 2023-08-04 jrmu   (define (list<? l1 l2)
13 665c255d 2023-08-04 jrmu     (andmap key<? l1 l2))
14 665c255d 2023-08-04 jrmu   (define (key<? key1 key2)
15 665c255d 2023-08-04 jrmu     (cond ((and (string? key1)
16 665c255d 2023-08-04 jrmu 		(string? key2)) (string<? key1 key2))
17 665c255d 2023-08-04 jrmu 	  ((and (number? key1)
18 665c255d 2023-08-04 jrmu 		(number? key2)) (< key1 key2))
19 665c255d 2023-08-04 jrmu 	  ((and (char? key1)
20 665c255d 2023-08-04 jrmu 		(char? key2)) (char<? key1 key2))
21 665c255d 2023-08-04 jrmu 	  (else (error "Unsupported key types -- KEY<?" key1 key2))))
22 665c255d 2023-08-04 jrmu   (define (element-of-set? x set)
23 665c255d 2023-08-04 jrmu     (cond ((null? set) false)
24 665c255d 2023-08-04 jrmu 	  ((key=? (key-record x) (key-record (entry set))) true)
25 665c255d 2023-08-04 jrmu 	  ((key<? (key-record x) (key-record (entry set))) 
26 665c255d 2023-08-04 jrmu 	   (element-of-set? x (left-branch set)))
27 665c255d 2023-08-04 jrmu 	  (else
28 665c255d 2023-08-04 jrmu 	   (element-of-set? x (right-branch set)))))
29 665c255d 2023-08-04 jrmu