1 module List = ListLabels
6 module Translate = Tiger_translate
7 module Type = Tiger_env_type
8 module Value = Tiger_env_value
10 (* The only reason for having this seemingly-superfluous inner module is to
11 * have this nice signature as a summary of what each function does. *)
18 (* Violating normal naming convention just to make it easier to follow
21 val transExp : env:Env.t -> A.exp -> expty
22 val transVar : env:Env.t -> A.var -> expty
23 val transDec : env:Env.t -> A.dec -> Env.t
24 val transTy : env:Env.t -> A.ty -> Type.t (* needs only type env *)
31 let unimplemented () =
32 failwith "unimplemented"
34 let return ty = {exp = (); ty}
35 let return_unit = return Type.Unit
36 let return_nil = return Type.Nil
37 let return_int = return Type.Int
38 let return_string = return Type.String
40 let env_get_typ ~sym ~env ~pos : Type.t =
41 match Env.get_typ env sym with
43 | None -> E.raise (E.Unknown_type {ty_id=sym; pos})
45 let env_get_val ~sym ~env ~pos : Value.t =
46 match Env.get_val env sym with
48 | None -> E.raise (E.Unknown_id {id=sym; pos})
50 let check_same {exp=_; ty=ty_left} {exp=_; ty=ty_right} ~pos : unit =
51 if Type.is_equal ty_left ty_right then
54 E.raise (E.Wrong_type {expected=ty_left; given=ty_right; pos})
56 let check_int expty ~pos : unit =
57 check_same {exp=(); ty=Type.Int} expty ~pos
59 let rec transExp ~env exp =
66 | A.StringExp {string=_; _} ->
68 | A.CallExp {func=_; args=_; pos=_} ->
70 | A.OpExp {oper; left; right; pos} ->
71 trop oper ~left ~right ~pos
72 | A.RecordExp {fields=_; typ=_; pos=_} ->
75 (* Ignoring value because we only care if a type-checking exception
76 * is raised in one of trexp calls: *)
77 List.iter exps ~f:(fun (exp, _) -> ignore (trexp exp));
79 | A.AssignExp {var; exp; pos} ->
80 check_same (trvar var) (trexp exp) ~pos;
81 (* TODO: Add var->exp to val env? *)
83 | A.IfExp {test; then'; else'; pos} ->
84 (* test : must be int, because we have no bool *)
85 (* then : must equal else *)
86 (* else : must equal then or be None *)
87 check_int (trexp test) ~pos;
88 (match (trexp then', else') with
91 | expty_then, Some else' ->
92 let expty_else = trexp else' in
93 check_same expty_then expty_else ~pos;
96 | A.WhileExp {test; body; pos} ->
97 (* test : must be int, because we have no bool *)
98 check_int (trexp test) ~pos;
99 ignore (trexp body); (* Only care if a type-error is raised *)
101 | A.ForExp {var; lo; hi; body; pos; escape=_} ->
102 check_int (trexp lo) ~pos;
103 check_int (trexp hi) ~pos;
104 (* Only care if a type-error is raised *)
105 ignore (transExp ~env:(Env.set_typ env var Type.Int) body);
109 | A.LetExp {decs=_; body=_; _} ->
111 | A.ArrayExp {typ=_; size=_; init=_; _} ->
118 | A.SimpleVar {symbol=sym; pos} ->
119 (match env_get_val ~sym ~env ~pos with
120 | Value.Fun _ -> E.raise (E.Id_is_a_function {id=sym; pos})
121 | Value.Var {ty} -> return ty
123 | A.FieldVar {var; symbol; pos} ->
124 let {exp=_; ty} = trvar var in
128 (match List.assoc_opt symbol fields with
131 (E.No_such_field_in_record {field=symbol; record=ty; pos})
136 ~otherwise:(fun () -> E.raise (E.Exp_not_a_record {ty; pos}))
137 | A.SubscriptVar {var=_; exp=_; pos=_} ->
140 and trop oper ~left ~right ~pos =
141 let expty_left = trexp left in
142 let expty_right = trexp right in
143 check_same expty_left expty_right ~pos;
144 let {exp=_; ty} = expty_left in
145 let module T = Type in
147 (* Arithmetic: int *)
152 check_int expty_left ~pos;
154 (* Equality: int, string, array, record *)
164 E.raise (E.Invalid_operand_type
166 ; valid = ["int"; "string"; "array"; "record"]
170 (* Order: int, string *)
180 E.raise (E.Invalid_operand_type
182 ; valid = ["int"; "string"]
190 let transVar ~env:_ var =
192 | A.SimpleVar {symbol=_; _} ->
194 | A.FieldVar {var=_; symbol=_; _} ->
196 | A.SubscriptVar {var=_; exp=_; _} ->
200 let transDec ~env:_ dec =
202 | A.VarDec {name=_; typ=_; init=_; pos=_; escape=_} ->
210 let transTy ~env:_ typ =
212 | A.NameTy {symbol = _; pos = _} ->
216 | A.ArrayTy {symbol = _; pos = _} ->
221 let transProg absyn =
223 let {exp = _; ty = _} = transExp absyn ~env:Env.base in