ref: b34fba0e5b9e39fc5120f06b6c335033472f81ca
parent: a5def38ade71a84c23154fa395375c5132be4cbf
author: smazga <smazga@greymanlabs.com>
date: Thu Aug 6 09:13:23 EDT 2020
added env and more filling out
--- /dev/null
+++ b/env.ml
@@ -1,0 +1,36 @@
+module T = Types.Types
+module Data = Map.Make (String)
+
+type env =
+ { outer : env option+ ; data : Types.m9type Data.t ref
+ }
+
+let make 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: not a symbol")
+;;
+
+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: not a symbol")
+;;
+
+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: not a symbol")
+;;