1c94591c27
* Expansion now proceeds correctly on all examples, although reduction does not * Drastically reorganized how wrapper work. * Added/remove TODOs
34 lines
682 B
Racket
34 lines
682 B
Racket
#lang s-exp "cur-redex.rkt"
|
|
(require "sugar.rkt")
|
|
(module+ test
|
|
(require rackunit))
|
|
|
|
(data nat : Type
|
|
(z : nat)
|
|
(s : (-> nat nat)))
|
|
|
|
(define (add1 (n : nat)) (s n))
|
|
(module+ test
|
|
(check-equal? (add1 (s z)) (s (s z))))
|
|
|
|
(define (sub1 (n : nat))
|
|
(case n
|
|
[z z]
|
|
[s (lambda (x : nat) x)]))
|
|
(module+ test
|
|
(check-equal? (sub1 (s z)) z))
|
|
|
|
(define plus
|
|
(fix (plus : (forall* (n1 : nat) (n2 : nat) nat))
|
|
(lambda (n1 : nat)
|
|
(lambda (n2 : nat)
|
|
(case n1
|
|
[z n2]
|
|
[s (λ (x : nat) (plus x (s n2)))])))))
|
|
(module+ test
|
|
(check-equal? (plus z z) z)
|
|
(check-equal? (plus (s (s z)) (s (s z))) (s (s (s (s z))))))
|
|
|
|
(add1 (s z))
|
|
(sub1 (s z))
|