suzanne.soy/macrotypes
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

add another polyrecur example

Browse Source
This commit is contained in:
Stephen Chang 2016-03-28 17:51:23 -04:00
parent 92b1f8ec45
commit 05969628ff
1 changed files with 22 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
tapl/tests/mlish/polyrecur.mlish
View File

@ -27,6 +27,7 @@
(size (Cons 1 (Cons (tup 2 3) (Cons (tup (tup 4 5) (tup 6 7)) Nil))))
: Int -> 7)
;; implicit queue
(define-type (Digit X)
(Zero)
(One X)
@ -66,3 +67,24 @@
(check-type (iq-isEmpty (Shallow (Zero {Int}))) : Bool -> #t)
(check-type (iq-isEmpty (iq-snoc (Shallow (Zero {Int})) 5)) : Bool -> #f)
;; example from:
;; blogs.janestreet.com/ensuring-that-a-function-is-polymorphic-in-ocaml-3-12
(define-type (PerfectTree X)
(Leaf X)
(Node X (PerfectTree (× X X))))
(define (flatten [t : (PerfectTree X)] -> (List X))
(match t with
[Leaf x -> (list x)]
[Node x rst ->
(cons x
(for/fold ([acc (nil {X})]) ([p (in-list (flatten rst))])
(match p with
[x y -> (cons x (cons y acc))])))]))
(check-type (flatten (Leaf 1)) : (List Int) -> (list 1))
(check-type (flatten (Node 1 (Leaf (tup 2 3)))) : (List Int) -> (list 1 2 3))
(check-type
(flatten (Node 1 (Node (tup 2 3) (Leaf (tup (tup 4 5) (tup 6 7))))))
: (List Int) -> (list 1 6 7 4 5 2 3))