Support index on array types

packages/demo/src/demo.re

@@ -1,14 +1,18 @@
 module StateLenses = [%lenses
- type state = {
-   email: string,
-   age: int,
- }
+  type state = {
+    email: string,
+    age: int,
+    hobbies: array(string),
+  }
 ];
-
-
 open StateLenses;
 
-let state = {email: "[email protected]", age: 0};
+let state = {
+  email: "[email protected]",
+  age: 0,
+  hobbies: [|"foo", "bar"|],
+};
 
 Js.log(state->get(Email));
 Js.log(state->get(Age));
+Js.log(state->get(HobbiesAt(1)));

packages/ppx/esy.lock/index.json

@@ -605,4 +605,4 @@
       "devDependencies": []
     }
   }
-}
+}

packages/ppx/test/Test.ml

@@ -1,15 +1,17 @@
 module FormConfig = struct
   module State = [%lenses
-  type t = {
-    email: string;
-    age: int;
-  };;
-]
-end;;
+    type t = {
+      email: string;
+      age: int;
+      hobbies: string array;
+    }
+  ]
+end
 
 module User = [%lenses
   type t = {
     email: string;
     age: int;
-  };;
+    hobbies: string array;
+  }
 ]

packages/ppx/test/Test.re

@@ -2,7 +2,8 @@ module State = [%lenses
   type state = {
     email: string,
     age: int,
+    hobbies: array(string),
   }
 ];
 
-let state: State.state = {email: "", age: 0};
+let state: State.state = {email: "", age: 0, hobbies: [|"foo", "bar"|]};

packages/ppx/test/Wanted.ml

@@ -1,24 +1,48 @@
 module FormConfig =
   struct
-    type _ field =
-      | Email: string field
-      | Age: int field
-    type state = {
-      email: string;
-      age: int;}
-    let get : 'value . state -> 'value field -> 'value= fun (type value) ->
-      (fun state  ->
-         fun field  ->
-           match field with | Email  -> state.email | Age  -> state.age : 
-      state -> value field -> value)
-    let set : 'value . state -> 'value field -> 'value -> state= fun (type
-      value) ->
-      (fun state  ->
-         fun field  ->
-           fun value  ->
-             match field with
-             | Email  -> { state with email = value }
-             | Age  -> { state with age = value } : state ->
-                                                      value field ->
-                                                        value -> state)
+    module State =
+      struct
+        type t = {
+          email: string;
+          age: int;
+          hobbies: string array;}
+        type _ field =
+          | Email: string field
+          | Age: int field
+          | Hobbies: string array field
+          | HobbiesAt: int -> string option field
+          | HobbiesAtExn: int -> string field
+        let get : 'value . t -> 'value field -> 'value= fun (type value) ->
+          (fun t  ->
+             fun field  ->
+               match field with
+               | Email  -> t.email
+               | Age  -> t.age
+               | Hobbies  -> t.hobbies
+               | HobbiesAt index ->
+                   (try Some ((t.hobbies).(index)) with | _ -> None)
+               | HobbiesAtExn index -> (t.hobbies).(index) : t ->
+                                                               value field ->
+                                                                 value)
+        let set : 'value . t -> 'value field -> 'value -> t= fun (type value)
+          ->
+          (fun t  ->
+             fun field  ->
+               fun value  ->
+                 match field with
+                 | Email  -> { t with email = value }
+                 | Age  -> { t with age = value }
+                 | Hobbies  -> { t with hobbies = value }
+                 | HobbiesAt index ->
+                     (match value with
+                      | Some value ->
+                          ((t.hobbies).(index) <- value;
+                           { t with hobbies = (t.hobbies) })
+                      | None  -> t)
+                 | HobbiesAtExn index ->
+                     ((t.hobbies).(index) <- value;
+                      { t with hobbies = (t.hobbies) }) : t ->
+                                                            value field ->
+                                                              value -> t)
+      end
   end