module List = ListLabels
module A = Tiger_absyn
+module Dag = Tiger_dag
module Env = Tiger_env
module E = Tiger_error
+module Pos = Tiger_position
+module Sym = Tiger_symbol
module Translate = Tiger_translate
module Type = Tiger_env_type
module Value = Tiger_env_value
; ty : Type.t
}
+ let rec actual_ty ty ~pos =
+ match ty with
+ | Type.Name (name, ty_opt_ref) ->
+ (match !ty_opt_ref with
+ | None ->
+ E.raise (E.Unknown_type {ty_id=name; pos})
+ | Some ty ->
+ actual_ty ty ~pos
+ )
+ | Type.Unit
+ | Type.Nil
+ | Type.Int
+ | Type.String
+ | Type.Record _
+ | Type.Array _ ->
+ ty
+
let return ty = {exp = (); ty}
let return_unit = return Type.Unit
let return_nil = return Type.Nil
| Some ty -> ty
| None -> E.raise (E.Unknown_type {ty_id=sym; pos})
+ let env_get_typ_actual ~sym ~env ~pos : Type.t =
+ actual_ty (env_get_typ ~sym ~env ~pos) ~pos
+
let env_get_val ~sym ~env ~pos : Value.t =
match Env.get_val env sym with
| Some ty -> ty
E.raise (E.Wrong_type {expected=ty_left; given=ty_right; pos})
let check_int expty ~pos : unit =
- check_same {exp=(); ty=Type.Int} expty ~pos
+ check_same return_int expty ~pos
- (* TODO: actual_ty *)
- (* TODO: mutual recursion *)
+ let paths_of_typedecs typedecs : (Sym.t * Sym.t * Pos.t) list list =
+ let (path, paths) =
+ List.fold_left typedecs ~init:([], []) ~f:(
+ fun (path, paths) (A.TypeDec {name=child; ty; pos}) ->
+ match ty with
+ | A.NameTy {symbol=parent; _} ->
+ (((parent, child, pos) :: path), paths)
+ | A.RecordTy _
+ | A.ArrayTy _ ->
+ ([], path :: paths)
+ )
+ in
+ List.map (path :: paths) ~f:List.rev
+
+ let check_cycles (typedecs : A.typedec list) : unit =
+ let non_empty_paths =
+ List.filter
+ (paths_of_typedecs typedecs)
+ ~f:(function [] -> false | _ -> true)
+ in
+ List.iter non_empty_paths ~f:(
+ fun path ->
+ match Dag.of_list (List.map path ~f:(fun (p, c, _) -> (p, c))) with
+ | Ok _ ->
+ ()
+ | Error `Cycle ->
+ let (_, from_id, from_pos) = List.hd path in
+ let (_, to_id, to_pos) = List.hd (List.rev path) in
+ E.raise (E.Cycle_in_type_decs {from_id; from_pos; to_id; to_pos})
+ )
let rec transExp ~env exp =
let rec trexp exp =
| A.CallExp {func; args; pos} ->
(match env_get_val ~sym:func ~env ~pos with
| Value.Fun {formals; result} ->
- List.iter2 formals args ~f:(fun ty_expected exp_given ->
- check_same {exp=(); ty = ty_expected} (trexp exp_given) ~pos;
- );
- return result
+ let expected = List.length formals in
+ let given = List.length args in
+ if given = expected then
+ begin
+ List.iter2 formals args ~f:(fun ty_expected exp_given ->
+ check_same
+ (return (actual_ty ~pos ty_expected))
+ (trexp exp_given)
+ ~pos;
+ );
+ return (actual_ty ~pos result)
+ end
+ else
+ E.raise (E.Wrong_number_of_args {func; expected; given; pos})
| Value.Var _ ->
E.raise (E.Id_not_a_function {id=func; pos})
)
| A.OpExp {oper; left; right; pos} ->
trop oper ~left ~right ~pos
| A.RecordExp {fields=field_exps; typ; pos} ->
- let ty = env_get_typ ~sym:typ ~env ~pos in
+ let ty = env_get_typ_actual ~sym:typ ~env ~pos in
Type.if_record
ty
~f:(fun field_tys ->
List.iter field_exps ~f:(fun (field, exp, pos) ->
(match List.assoc_opt field field_tys with
| Some field_ty ->
- check_same {exp=(); ty=field_ty} (trexp exp) ~pos
+ check_same (return (actual_ty ~pos field_ty)) (trexp exp) ~pos
| None ->
E.raise
(E.No_such_field_in_record {field; record=ty; pos})
~otherwise:(fun () ->
E.raise (E.Wrong_type_used_as_record {ty_id=typ; ty; pos})
);
- return ty
- | A.SeqExp exps ->
- (* Ignoring value because we only care if a type-checking exception
- * is raised in one of trexp calls: *)
- List.iter exps ~f:(fun (exp, _) -> ignore (trexp exp));
- (* FIXME: Return type of last expression, not unit. *)
+ return (actual_ty ~pos ty)
+ | A.SeqExp [] ->
return_unit
+ | A.SeqExp exps ->
+ let last xs =
+ xs
+ |> List.rev (* Yes, redundant, but clean-looking ;-P *)
+ |> List.hd (* Empty is matched in above SeqExp match case *)
+ in
+ exps
+ |> List.map ~f:(fun (exp, _) -> trexp exp)
+ |> last
| A.AssignExp {var; exp; pos} ->
check_same (trvar var) (trexp exp) ~pos;
(* TODO: Add var->exp to val env? *)
transExp body ~env
| A.ArrayExp {typ; size; init; pos} ->
check_int (trexp size) ~pos;
- let ty = env_get_typ ~sym:typ ~env ~pos in
+ let ty = env_get_typ_actual ~sym:typ ~env ~pos in
Type.if_array
ty
~f:(fun ty_elements ->
- check_same {exp=(); ty=ty_elements} (trexp init) ~pos
+ check_same (return (actual_ty ~pos ty_elements)) (trexp init) ~pos
)
~otherwise:(fun () ->
E.raise (E.Wrong_type_used_as_array {ty_id=typ; ty; pos})
);
- return ty
+ return (actual_ty ~pos ty)
| A.VarExp var ->
trvar var
)
| A.SimpleVar {symbol=sym; pos} ->
(match env_get_val ~sym ~env ~pos with
| Value.Fun _ -> E.raise (E.Id_is_a_function {id=sym; pos})
- | Value.Var {ty} -> return ty
+ | Value.Var {ty} -> return (actual_ty ~pos ty)
)
| A.FieldVar {var; symbol; pos} ->
let {exp=_; ty} = trvar var in
E.raise
(E.No_such_field_in_record {field=symbol; record=ty; pos})
| Some ty ->
- return ty
+ return (actual_ty ~pos ty)
)
)
~otherwise:(fun () -> E.raise (E.Exp_not_a_record {ty; pos}))
check_int (trexp exp) ~pos;
Type.if_array
ty
- ~f:(fun ty_elements -> return ty_elements)
+ ~f:(fun ty_elements -> return (actual_ty ~pos ty_elements))
~otherwise:(fun () -> E.raise (E.Exp_not_an_array {ty; pos}))
)
and trop oper ~left ~right ~pos =
+ (* TODO: Refactor trop - all opers return bool/int *)
let expty_left = trexp left in
let expty_right = trexp right in
check_same expty_left expty_right ~pos;
|| (T.is_array ty)
|| (T.is_record ty)
then
- return ty
+ return_int (* Because we have no bool type *)
else
E.raise (E.Invalid_operand_type
{ oper
if (T.is_int ty)
|| (T.is_string ty)
then
- return ty
+ return_int (* Because we have no bool type *)
else
E.raise (E.Invalid_operand_type
{ oper
| None, {ty; exp=()} ->
ty
| Some (sym, pos_inner), expty_init ->
- let ty = env_get_typ ~sym ~env ~pos:pos_inner in
- check_same {exp=(); ty} expty_init ~pos:pos_outter;
+ let ty = env_get_typ_actual ~sym ~env ~pos:pos_inner in
+ check_same (return ty) expty_init ~pos:pos_outter;
ty
)
in
Env.set_val env name (Value.Var {ty})
| A.TypeDecs typedecs ->
- List.fold_left typedecs ~init:env ~f:(
- fun env (A.TypeDec {name; ty; pos=_}) ->
- let ty = transTy ~env ty in
- Env.set_typ env name ty
- )
+ check_cycles typedecs;
+ let env =
+ List.fold_left typedecs ~init:env ~f:(
+ fun env (A.TypeDec {name; ty=_; pos=_}) ->
+ Env.set_typ env name (Type.Name (name, ref None))
+ )
+ in
+ List.iter typedecs ~f:(fun (A.TypeDec {name; ty=ty_exp; pos}) ->
+ let ty = transTy ~env ty_exp in
+ (match env_get_typ ~sym:name ~env ~pos with
+ | Type.Name (_, ty_opt_ref) ->
+ ty_opt_ref := Some ty
+ | Type.Unit
+ | Type.Nil
+ | Type.Int
+ | Type.String
+ | Type.Record _
+ | Type.Array _ ->
+ ()
+ )
+ );
+ env
| A.FunDecs fundecs ->
- List.fold_left fundecs ~init:env ~f:(
- fun env (A.FunDec {name; params; result; body; pos=_}) ->
- let (env_for_body, formals_in_reverse_order) =
- List.fold_left params ~init:(env, []) ~f:(
- fun (env, formals) (A.Field {name; escape=_; typ; pos}) ->
- let ty = env_get_typ ~env ~sym:typ ~pos in
- let env = Env.set_val env name (Value.Var {ty}) in
- (env, ty :: formals)
+ let env_with_fun_heads_only =
+ List.fold_left fundecs ~init:env ~f:(
+ fun env (A.FunDec {name; params; result; body=_; pos=_}) ->
+ let formals =
+ List.map params ~f:(
+ fun (A.Field {name=_; typ; pos; escape=_}) ->
+ env_get_typ_actual ~env ~sym:typ ~pos
+ )
+ in
+ let result =
+ match result with
+ | Some (s, p) -> env_get_typ_actual ~sym:s ~env ~pos:p
+ | None -> Type.Unit
+ in
+ Env.set_val env name (Value.Fun {formals; result})
+ )
+ in
+ List.iter fundecs ~f:(
+ fun (A.FunDec {name=_; params; result=_; body; pos=_}) ->
+ let env_with_fun_heads_and_local_vars =
+ List.fold_left params ~init:env_with_fun_heads_only ~f:(
+ fun env (A.Field {name=var_name; escape=_; typ; pos}) ->
+ let var_ty = env_get_typ_actual ~env ~sym:typ ~pos in
+ Env.set_val env var_name (Value.Var {ty = var_ty})
)
in
- (* ignore because we only care if an exception is raised *)
- ignore (transExp ~env:env_for_body body);
- let formals = List.rev formals_in_reverse_order in
- let result =
- match result with
- | None ->
- Type.Unit
- | Some (sym, pos) ->
- env_get_typ ~sym ~env ~pos
- in
- Env.set_val env name (Value.Fun {formals; result})
- )
+ (* we only care if an exception is raised *)
+ ignore (transExp ~env:env_with_fun_heads_and_local_vars body);
+ );
+ env_with_fun_heads_only
)
- and transTy ~(env : Env.t) (typ : A.ty) : Type.t =
- (match typ with
+ and transTy ~(env : Env.t) (ty_exp : A.ty) : Type.t =
+ (match ty_exp with
| A.NameTy {symbol=sym; pos} ->
env_get_typ ~sym ~env ~pos
| A.RecordTy fields ->
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