Merge pull request #3 from Chouser/ocaml

Ocaml

1 files changed, 33 insertions, 0 deletions

diff --git a/ocaml/env.ml b/ocaml/env.ml
new file mode 100644
index 0000000..cb32360
--- /dev/null
+++ b/ocaml/env.ml
@@ -0,0 +1,33 @@
+module T = Types.Types
+module Data = Map.Make (String)
+
+type env = {
+  outer : env option;
+  data : Types.mal_type Data.t ref;
+}
+
+let make outer = { outer = outer; data = ref Data.empty }
+
+let set env sym value =
+  match sym with
+    | T.Symbol { T.value = key } -> env.data := Data.add key value !(env.data)
+    | _ -> raise (Invalid_argument "set requires a Symbol for its key")
+
+let rec find env sym =
+  match sym with
+    | T.Symbol { T.value = key } ->
+        (if Data.mem key !(env.data) then
+           Some env
+         else
+           match env.outer with
+             | Some outer -> find outer sym
+             | None -> None)
+    | _ -> raise (Invalid_argument "find requires a Symbol for its key")
+
+let get env sym =
+  match sym with
+    | T.Symbol { T.value = key } ->
+      (match find env sym with
+         | Some found_env -> Data.find key !(found_env.data)
+         | None -> raise (Invalid_argument ("'" ^ key ^ "' not found")))
+    | _ -> raise (Invalid_argument "get requires a Symbol for its key")