Category: Functional Programming

Exercise 3.28.  Define an or-gate as a primitive function box. Your or-gate constructor should be similar to and-gate.

 

 

Exercise 3.24.  In the table implementations above, the keys are tested for equality using equal? (called by assoc). This is not always the appropriate test. For instance, we might have a table with numeric keys in which we don’t need an exact match to the number we’re looking up, but only a number within some tolerance of it. Design a table constructor make-table that takes as an argument a same-key? procedure that will be used to test “equality” of keys. Make-table should return a dispatch procedure that can be used to access appropriate lookup and insert! procedures for a local table.

 

 

Exercise 3.22.  Instead of representing a queue as a pair of pointers, we can build a queue as a procedure with local state. The local state will consist of pointers to the beginning and the end of an ordinary list. Thus, the make-queue procedure will have the form

(define (make-queue)
(let ((front-ptr ...)
(rear-ptr ...))
<definitions of internal procedures>
(define (dispatch m) ...)
dispatch))

Complete the definition of make-queue and provide implementations of the queue operations using this representation.