Lecture 14 Objectives

At the end of today's class you should

KNOW:

That the data definition for an ancestor family tree (a fixed-width tree) requires a self-referential struct inside a struct.

BE ABLE TO:

Write the data definition for an ancestor family tree.
Generate the template for an ancestor family tree from the data definition.
Write functions over ancestor family trees.

Sample Exam Question:

Consider the following definition of family trees used in a medical database:

   ;; An ftree is either
   ;; 'unknown, or
   ;; (make-person string symbol ftree ftree)

   (define-struct person (name bloodtype father mother))

   ;; where bloodtype is one of 'A, 'B, 'AB, or 'O

Write a function count-type that consumes a bloodtype and a family tree and produces the number of people in the family tree who have the given bloodtype.

;; count-type: symbol ftree -> number
;; consumes a bloodtype and a family tree and produces the number of people
;; with that bloodtype