1 665c255d 2023-08-04 jrmu (define (attach-tag type-tag contents)
 2 665c255d 2023-08-04 jrmu   (if (= type-tag 'scheme-number)
 3 665c255d 2023-08-04 jrmu       contents
 4 665c255d 2023-08-04 jrmu       (cons type-tag contents)))
 5 665c255d 2023-08-04 jrmu (define (type-tag datum)
 6 665c255d 2023-08-04 jrmu   (cond ((number? datum) 'scheme-number)
 7 665c255d 2023-08-04 jrmu 	((pair? datum) (car datum))
 8 665c255d 2023-08-04 jrmu 	(else (error "Bad tagged datum -- TYPE-TAG" datum))))
 9 665c255d 2023-08-04 jrmu (define (contents datum)
10 665c255d 2023-08-04 jrmu   (cond ((number? datum) datum)
11 665c255d 2023-08-04 jrmu 	((pair? datum) (cdr datum))
12 665c255d 2023-08-04 jrmu 	(else (error "Bad tagged datum -- CONTENTS" datum))))