diff options
Diffstat (limited to '')
| -rw-r--r-- | src/Contexts.ml | 37 |
1 files changed, 22 insertions, 15 deletions
diff --git a/src/Contexts.ml b/src/Contexts.ml index f182add5..8a498e2e 100644 --- a/src/Contexts.ml +++ b/src/Contexts.ml @@ -58,15 +58,17 @@ let ctx_lookup_fun_def (ctx : eval_ctx) (fid : FunDefId.id) : fun_def = (** Retrieve a variable's value in an environment *) let env_lookup_var_value (env : env) (vid : VarId.id) : typed_value = - (* TOOD: we might want to stop at the end of the frame *) - let check_ev (ev : env_value) : typed_value option = - match ev with - | Var (var, v) -> if var.index = vid then Some v else None - | Abs _ | Frame -> None + (* We take care to stop at the end of current frame: different variables + in different frames can have the same id! + *) + let rec lookup env = + match env with + | [] -> failwith "Unexpected" + | Var (var, v) :: env' -> if var.index = vid then v else lookup env' + | Abs _ :: env' -> lookup env' + | Frame :: _ -> failwith "End of frame" in - match List.find_map check_ev env with - | None -> failwith "Unreachable" - | Some v -> v + lookup env (** Retrieve a variable's value in an evaluation context *) let ctx_lookup_var_value (ctx : eval_ctx) (vid : VarId.id) : typed_value = @@ -78,14 +80,19 @@ let ctx_lookup_var_value (ctx : eval_ctx) (vid : VarId.id) : typed_value = any check. *) let env_update_var_value (env : env) (vid : VarId.id) (nv : typed_value) : env = - (* TOOD: we might want to stop at the end of the frame *) - let update_ev (ev : env_value) : env_value = - match ev with - | Var (var, v) -> if var.index = vid then Var (var, nv) else Var (var, v) - | Abs abs -> Abs abs - | Frame -> Frame + (* We take care to stop at the end of current frame: different variables + in different frames can have the same id! + *) + let rec update env = + match env with + | [] -> failwith "Unexpected" + | Var (var, v) :: env' -> + if var.index = vid then Var (var, nv) :: env' + else Var (var, v) :: update env' + | Abs abs :: env' -> Abs abs :: update env' + | Frame :: _ -> failwith "End of frame" in - List.map update_ev env + update env (** Update a variable's value in an evaluation context. |