Bigger Example

#require "core";;
#require "incremental";;

open Core;;

module Inc = Incremental.Make ();;
module Var = Inc.Var;;

 1let inputs = Array.init 100_000 ~f:(fun _ -> Inc.Var.create 0.);;
 2
 3let incr_list_sum l = 
 4match List.reduce_balanced l ~f:(Inc.map2 ~f:( +. )) with
 5| None -> Var.watch (Var.create 0.)
 6| Some x -> x;;
 7
 8let sum = 
 9List.map ~f:Inc.Var.watch (Array.to_list inputs)
10|> incr_list_sum
11|> Inc.observe;;
12
13
14Inc.stabilize ();;
15
16Inc.Observer.value_exn sum;;

- : float = 0.

1let incr i x = Inc.Var.set inputs.(i) (Inc.Var.value inputs.(i) +. x) in
2incr 100 1.6;
3incr 72 0.2;
4incr 105 0.4;
5Inc.stabilize ();;
6
7Inc.Observer.value_exn sum;;

- : float = 2.2

1#require "ppx_jane";;
2open Inc.Let_syntax;;

 1type z =
 2{ a: int list
 3; b: (int * int)
 4};;
 5(*  [@@deriving fields ~getters] ;; *)
 6
 7let sumproduct z =
 8    let a_prod =
 9      let%map a = z >>| (fun (d:z) -> d.a ) in
10      printf "a\n";
11      List.fold ~init:1 ~f:( * ) a
12    in
13    let b_prod =
14      let%map (b1,b2) = z >>| (fun (d:z) -> d.b ) in
15      printf "b\n";
16      b1 * b2
17    in
18    let%map a_prod = a_prod and b_prod = b_prod in
19    a_prod + b_prod
20;;
21
22let q = Inc.Var.create { a = [3;2]; b = (1,4) };;
23
24let result = Inc.observe (sumproduct (Inc.Var.watch q));;
25
26let show () =
27    Inc.stabilize ();
28    printf "result: %d\n" (Inc.Observer.value_exn result);;
29
30let () = show ();;

b
a
result: 10

1let () = 
2Inc.Var.set q { (Inc.Var.value q) with b = (1,1) };
3show ();;

b
result: 7