X-Git-Url: https://git.xandkar.net/?a=blobdiff_plain;f=compiler%2Fsrc%2Flib%2Ftiger%2Ftiger_env.ml;h=504e9bde71f5d3c9bb5f76b0a1fc20f20d1a64b8;hb=fd2204fa98928a900f303209818dce7f2bae3c8a;hp=f698f89563175a094cdcc27f02e17cf85cc0b076;hpb=c0bdf964d389a2b9465fad44aa1f1f849c72140f;p=tiger.ml.git

diff --git a/compiler/src/lib/tiger/tiger_env.ml b/compiler/src/lib/tiger/tiger_env.ml
index f698f89..504e9bd 100644
--- a/compiler/src/lib/tiger/tiger_env.ml
+++ b/compiler/src/lib/tiger/tiger_env.ml
@@ -1,15 +1,18 @@
 module Map   = Tiger_map
+module Sym   = Tiger_symbol
 module Type  = Tiger_env_type
 module Value = Tiger_env_value
 
 type t =
   { typs : Type.env
   ; vals : Value.env
+  ; loop : Sym.t option
   }
 
 let base =
   { typs = Type.built_in
   ; vals = Value.built_in
+  ; loop = None
   }
 
 let get_typ {typs; _} k =
@@ -23,3 +26,20 @@ let set_typ t k v =
 
 let set_val t k v =
   {t with vals = Map.set t.vals ~k ~v}
+
+let loop_begin t =
+  let loop = Sym.unique_of_string "loop" in
+  let t = {t with loop = Some loop} in
+  (loop, t)
+
+let loop_end t given =
+  match t.loop with
+  | None ->
+      assert false
+  | Some current when (not (Sym.is_equal current given)) ->
+      assert false
+  | Some _ ->
+      {t with loop = None}
+
+let loop_current {loop; _} =
+  loop