feat: support for model-requested horizons

exm/zelus/ballz/ballz.zls

@@ -9,8 +9,7 @@ let hybrid ball (y0, y'0) = (y, y', z) where
 
 let hybrid main () =
   let der t = 1.0 init 0.0 in
-  let rec der p = 1.0 init -0.01 reset s -> -0.01
-      and s = up(p) in 
+  let s = period(0.01) in
   let (y, y', z) = ball (y0, y'0) in
   present z | s -> (
     print_float t;

exm/zelus/ballz/dune

@@ -1,6 +1,6 @@
 (rule
- (targets ballz.ml ballz.zci)
+ (targets ballz.ml ballz.zci ballz_main.ml)
  (deps
   (:zl ballz.zls))
  (action
-  (run zeluc %{zl})))
+  (run zeluc -s main -o ballz_main %{zl})))

exm/zelus/count/count.zls

@@ -0,0 +1,4 @@
+
+let node count () =
+  let rec n = 0 -> (pre n + 1) in
+  print_int n; print_newline ()

exm/zelus/count/dune

@@ -0,0 +1,6 @@
+(rule
+ (targets count.ml count.zci)
+ (deps
+  (:zl count.zls))
+ (action
+  (run zeluc %{zl})))

exm/zelus/sincos/sincosz.zls

@@ -1,4 +1,17 @@
 
-let hybrid f () = (sin, cos) where
+let hybrid g () = (sin, cos) where
   rec der sin = cos init 0.0
   and der cos = -. sin init 1.0
+
+let hybrid f () =
+  let der t = 1.0 init 0.0 in
+  let sin, cos = g () in
+  let z = period (0.01) in
+  present z -> (
+    print_float t;
+    print_string "\t";
+    print_float sin;
+    print_string "\t";
+    print_float cos;
+    print_newline ()
+  ); ()