1 665c255d 2023-08-04 jrmu (define (attach-tag type-tag contents)
 2 665c255d 2023-08-04 jrmu   (if (number? contents)
 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  -- TYPE-TAG" datum))))
13 665c255d 2023-08-04 jrmu 
14 665c255d 2023-08-04 jrmu (put 'real-part '(complex) real-part)
15 665c255d 2023-08-04 jrmu (put 'imag-part '(complex) imag-part)
16 665c255d 2023-08-04 jrmu (put 'magnitude '(complex) magnitude)
17 665c255d 2023-08-04 jrmu (put 'angle '(complex) angle)
18 665c255d 2023-08-04 jrmu