;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;                              people.scm
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(define person (make-record-type "person" 
				 '(name sex age father mother weight)))
(define make-person (record-constructor person))

(define person? (record-predicate person))

(define name.person (record-accessor person 'name))
(define sex.person (record-accessor person 'sex))
(define age.person (record-accessor person 'age))
(define father.person (record-accessor person 'father))
(define mother.person (record-accessor person 'mother))
(define weight.person (record-accessor person 'weight))

(define age.person! (record-modifier person 'age))
(define weight.person! (record-modifier person 'weight))

;;;;;;;;;; now make persons etc ;;;;;;;;;;;;;;;;;

(define dad (make-person "patrick" 'male 45 nil nil 168))
(define mum (make-person "andrea" 'female 41 nil nil 100))
(define zoe (make-person "zoe" 'female 4.9 dad mum 30))

(define (show.person p) ;name sex age father mother weight
  (list (name.person p)
	(sex.person p)
	(age.person p)
	(cond ((father.person p) (name.person (father.person p)))
	      (#t 'unknown))
	(cond ((mother.person p) (name.person (mother.person p)))
	      (#t 'unknown))
	(weight.person p)))

;(show.person zoe)
;(age.person! zoe 5)
;(show.person zoe)
;(show.person dad)