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523e2b06 SK |
1 | module List = ListLabels |
2 | ||
155ee327 SK |
3 | module A = Tiger_absyn |
4 | module Env = Tiger_env | |
5 | module E = Tiger_error | |
155ee327 SK |
6 | module Translate = Tiger_translate |
7 | module Type = Tiger_env_type | |
8 | module Value = Tiger_env_value | |
9 | ||
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. *) | |
12 | module Semant : sig | |
13 | type expty = | |
14 | { exp : Translate.exp | |
15 | ; ty : Type.t | |
16 | } | |
17 | ||
18 | (* Violating normal naming convention just to make it easier to follow | |
19 | * Appel's | |
20 | *) | |
21 | val transExp : env:Env.t -> A.exp -> expty | |
862e5c05 SK |
22 | |
23 | (* transVar does not seem to be needed, as trvar handles all our cases. | |
24 | * Am I wrong? | |
25 | * | |
26 | * val transVar : env:Env.t -> A.var -> expty | |
27 | * | |
28 | *) | |
155ee327 SK |
29 | end = struct |
30 | type expty = | |
31 | { exp : Translate.exp | |
32 | ; ty : Type.t | |
33 | } | |
34 | ||
cbb4ffb6 SK |
35 | let rec actual_ty ty ~pos = |
36 | match ty with | |
37 | | Type.Name (name, ty_opt_ref) -> | |
38 | (match !ty_opt_ref with | |
39 | | None -> | |
40 | E.raise (E.Unknown_type {ty_id=name; pos}) | |
41 | | Some ty -> | |
42 | actual_ty ty ~pos | |
43 | ) | |
44 | | Type.Unit | |
45 | | Type.Nil | |
46 | | Type.Int | |
47 | | Type.String | |
48 | | Type.Record _ | |
49 | | Type.Array _ -> | |
50 | ty | |
51 | ||
523e2b06 SK |
52 | let return ty = {exp = (); ty} |
53 | let return_unit = return Type.Unit | |
54 | let return_nil = return Type.Nil | |
55 | let return_int = return Type.Int | |
56 | let return_string = return Type.String | |
155ee327 | 57 | |
523e2b06 SK |
58 | let env_get_typ ~sym ~env ~pos : Type.t = |
59 | match Env.get_typ env sym with | |
60 | | Some ty -> ty | |
61 | | None -> E.raise (E.Unknown_type {ty_id=sym; pos}) | |
62 | ||
cbb4ffb6 SK |
63 | let env_get_typ_actual ~sym ~env ~pos : Type.t = |
64 | actual_ty (env_get_typ ~sym ~env ~pos) ~pos | |
65 | ||
523e2b06 SK |
66 | let env_get_val ~sym ~env ~pos : Value.t = |
67 | match Env.get_val env sym with | |
68 | | Some ty -> ty | |
69 | | None -> E.raise (E.Unknown_id {id=sym; pos}) | |
70 | ||
71 | let check_same {exp=_; ty=ty_left} {exp=_; ty=ty_right} ~pos : unit = | |
72 | if Type.is_equal ty_left ty_right then | |
73 | () | |
74 | else | |
75 | E.raise (E.Wrong_type {expected=ty_left; given=ty_right; pos}) | |
76 | ||
77 | let check_int expty ~pos : unit = | |
cbb4ffb6 | 78 | check_same return_int expty ~pos |
978cb41c | 79 | |
523e2b06 SK |
80 | let rec transExp ~env exp = |
81 | let rec trexp exp = | |
82 | (match exp with | |
83 | | A.NilExp -> | |
84 | return_nil | |
85 | | A.IntExp _ -> | |
86 | return_int | |
87 | | A.StringExp {string=_; _} -> | |
88 | return_string | |
978cb41c SK |
89 | | A.CallExp {func; args; pos} -> |
90 | (match env_get_val ~sym:func ~env ~pos with | |
91 | | Value.Fun {formals; result} -> | |
54e838f4 SK |
92 | let expected = List.length formals in |
93 | let given = List.length args in | |
94 | if given = expected then | |
95 | begin | |
96 | List.iter2 formals args ~f:(fun ty_expected exp_given -> | |
97 | check_same | |
98 | (return (actual_ty ~pos ty_expected)) | |
99 | (trexp exp_given) | |
100 | ~pos; | |
101 | ); | |
102 | return (actual_ty ~pos result) | |
103 | end | |
104 | else | |
105 | E.raise (E.Wrong_number_of_args {func; expected; given; pos}) | |
978cb41c SK |
106 | | Value.Var _ -> |
107 | E.raise (E.Id_not_a_function {id=func; pos}) | |
108 | ) | |
523e2b06 SK |
109 | | A.OpExp {oper; left; right; pos} -> |
110 | trop oper ~left ~right ~pos | |
0ed7a07c | 111 | | A.RecordExp {fields=field_exps; typ; pos} -> |
cbb4ffb6 | 112 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
0ed7a07c SK |
113 | Type.if_record |
114 | ty | |
115 | ~f:(fun field_tys -> | |
116 | List.iter field_exps ~f:(fun (field, exp, pos) -> | |
117 | (match List.assoc_opt field field_tys with | |
118 | | Some field_ty -> | |
cbb4ffb6 | 119 | check_same (return (actual_ty ~pos field_ty)) (trexp exp) ~pos |
0ed7a07c SK |
120 | | None -> |
121 | E.raise | |
122 | (E.No_such_field_in_record {field; record=ty; pos}) | |
123 | ) | |
124 | ) | |
125 | ) | |
126 | ~otherwise:(fun () -> | |
127 | E.raise (E.Wrong_type_used_as_record {ty_id=typ; ty; pos}) | |
128 | ); | |
cbb4ffb6 | 129 | return (actual_ty ~pos ty) |
9d8471b2 | 130 | | A.SeqExp [] -> |
523e2b06 | 131 | return_unit |
9d8471b2 SK |
132 | | A.SeqExp exps -> |
133 | let last xs = | |
134 | xs | |
135 | |> List.rev (* Yes, redundant, but clean-looking ;-P *) | |
136 | |> List.hd (* Empty is matched in above SeqExp match case *) | |
137 | in | |
138 | exps | |
cbb4ffb6 | 139 | |> List.map ~f:(fun (exp, _) -> trexp exp) |
9d8471b2 | 140 | |> last |
523e2b06 SK |
141 | | A.AssignExp {var; exp; pos} -> |
142 | check_same (trvar var) (trexp exp) ~pos; | |
143 | (* TODO: Add var->exp to val env? *) | |
144 | return_unit | |
145 | | A.IfExp {test; then'; else'; pos} -> | |
146 | (* test : must be int, because we have no bool *) | |
147 | (* then : must equal else *) | |
148 | (* else : must equal then or be None *) | |
149 | check_int (trexp test) ~pos; | |
150 | (match (trexp then', else') with | |
151 | | expty_then, None -> | |
152 | expty_then | |
153 | | expty_then, Some else' -> | |
154 | let expty_else = trexp else' in | |
155 | check_same expty_then expty_else ~pos; | |
156 | expty_then | |
157 | ) | |
158 | | A.WhileExp {test; body; pos} -> | |
159 | (* test : must be int, because we have no bool *) | |
160 | check_int (trexp test) ~pos; | |
161 | ignore (trexp body); (* Only care if a type-error is raised *) | |
162 | return_unit | |
163 | | A.ForExp {var; lo; hi; body; pos; escape=_} -> | |
164 | check_int (trexp lo) ~pos; | |
165 | check_int (trexp hi) ~pos; | |
166 | (* Only care if a type-error is raised *) | |
85e08b69 SK |
167 | let env = Env.set_val env var (Value.Var {ty = Type.Int}) in |
168 | ignore (transExp ~env body); | |
523e2b06 SK |
169 | return_unit |
170 | | A.BreakExp _ -> | |
171 | return_unit | |
8744eb3a SK |
172 | | A.LetExp {decs; body; pos=_} -> |
173 | (* (1) decs augment env *) | |
174 | (* (2) body checked against the new env *) | |
175 | let env = | |
176 | List.fold_left decs ~init:env ~f:(fun env dec -> transDec dec ~env) | |
177 | in | |
178 | transExp body ~env | |
4c550cd5 SK |
179 | | A.ArrayExp {typ; size; init; pos} -> |
180 | check_int (trexp size) ~pos; | |
cbb4ffb6 | 181 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
4c550cd5 SK |
182 | Type.if_array |
183 | ty | |
184 | ~f:(fun ty_elements -> | |
cbb4ffb6 | 185 | check_same (return (actual_ty ~pos ty_elements)) (trexp init) ~pos |
4c550cd5 SK |
186 | ) |
187 | ~otherwise:(fun () -> | |
188 | E.raise (E.Wrong_type_used_as_array {ty_id=typ; ty; pos}) | |
189 | ); | |
cbb4ffb6 | 190 | return (actual_ty ~pos ty) |
523e2b06 SK |
191 | | A.VarExp var -> |
192 | trvar var | |
193 | ) | |
194 | and trvar = | |
195 | (function | |
196 | | A.SimpleVar {symbol=sym; pos} -> | |
197 | (match env_get_val ~sym ~env ~pos with | |
198 | | Value.Fun _ -> E.raise (E.Id_is_a_function {id=sym; pos}) | |
cbb4ffb6 | 199 | | Value.Var {ty} -> return (actual_ty ~pos ty) |
523e2b06 SK |
200 | ) |
201 | | A.FieldVar {var; symbol; pos} -> | |
202 | let {exp=_; ty} = trvar var in | |
203 | Type.if_record | |
204 | ty | |
205 | ~f:(fun fields -> | |
206 | (match List.assoc_opt symbol fields with | |
207 | | None -> | |
208 | E.raise | |
209 | (E.No_such_field_in_record {field=symbol; record=ty; pos}) | |
210 | | Some ty -> | |
cbb4ffb6 | 211 | return (actual_ty ~pos ty) |
523e2b06 SK |
212 | ) |
213 | ) | |
214 | ~otherwise:(fun () -> E.raise (E.Exp_not_a_record {ty; pos})) | |
161a300d SK |
215 | | A.SubscriptVar {var; exp; pos} -> |
216 | let {exp=_; ty} = trvar var in | |
217 | check_int (trexp exp) ~pos; | |
218 | Type.if_array | |
219 | ty | |
cbb4ffb6 | 220 | ~f:(fun ty_elements -> return (actual_ty ~pos ty_elements)) |
161a300d | 221 | ~otherwise:(fun () -> E.raise (E.Exp_not_an_array {ty; pos})) |
523e2b06 SK |
222 | ) |
223 | and trop oper ~left ~right ~pos = | |
cbb4ffb6 | 224 | (* TODO: Refactor trop - all opers return bool/int *) |
523e2b06 SK |
225 | let expty_left = trexp left in |
226 | let expty_right = trexp right in | |
227 | check_same expty_left expty_right ~pos; | |
228 | let {exp=_; ty} = expty_left in | |
229 | let module T = Type in | |
230 | (match oper with | |
231 | (* Arithmetic: int *) | |
232 | | A.PlusOp | |
233 | | A.MinusOp | |
234 | | A.TimesOp | |
235 | | A.DivideOp -> | |
236 | check_int expty_left ~pos; | |
237 | return_int | |
238 | (* Equality: int, string, array, record *) | |
239 | | A.EqOp | |
240 | | A.NeqOp -> | |
241 | if (T.is_int ty) | |
242 | || (T.is_string ty) | |
243 | || (T.is_array ty) | |
244 | || (T.is_record ty) | |
245 | then | |
cbb4ffb6 | 246 | return_int (* Because we have no bool type *) |
523e2b06 SK |
247 | else |
248 | E.raise (E.Invalid_operand_type | |
249 | { oper | |
250 | ; valid = ["int"; "string"; "array"; "record"] | |
251 | ; given = ty | |
252 | ; pos | |
253 | }) | |
254 | (* Order: int, string *) | |
255 | | A.LtOp | |
256 | | A.LeOp | |
257 | | A.GtOp | |
258 | | A.GeOp -> | |
259 | if (T.is_int ty) | |
260 | || (T.is_string ty) | |
261 | then | |
cbb4ffb6 | 262 | return_int (* Because we have no bool type *) |
523e2b06 SK |
263 | else |
264 | E.raise (E.Invalid_operand_type | |
265 | { oper | |
266 | ; valid = ["int"; "string"] | |
267 | ; given = ty | |
268 | ; pos | |
269 | }) | |
270 | ) | |
271 | in | |
272 | trexp exp | |
862e5c05 | 273 | and transDec ~(env : Env.t) (dec : A.dec) : Env.t = |
8744eb3a SK |
274 | (match dec with |
275 | | A.VarDec {name; typ=typ_opt; init; pos=pos_outter; escape=_} -> | |
276 | let ty = | |
277 | (match (typ_opt, transExp ~env init) with | |
278 | | None, {ty; exp=()} -> | |
279 | ty | |
280 | | Some (sym, pos_inner), expty_init -> | |
cbb4ffb6 SK |
281 | let ty = env_get_typ_actual ~sym ~env ~pos:pos_inner in |
282 | check_same (return ty) expty_init ~pos:pos_outter; | |
8744eb3a SK |
283 | ty |
284 | ) | |
285 | in | |
286 | Env.set_val env name (Value.Var {ty}) | |
0324a942 | 287 | | A.TypeDecs typedecs -> |
cbb4ffb6 SK |
288 | let env = |
289 | List.fold_left typedecs ~init:env ~f:( | |
290 | fun env (A.TypeDec {name; ty=_; pos=_}) -> | |
291 | Env.set_typ env name (Type.Name (name, ref None)) | |
292 | ) | |
293 | in | |
294 | List.iter typedecs ~f:(fun (A.TypeDec {name; ty=ty_exp; pos}) -> | |
295 | let ty = transTy ~env ty_exp in | |
296 | (match env_get_typ ~sym:name ~env ~pos with | |
9340b0e3 | 297 | | Type.Name (_, ty_opt_ref) -> |
cbb4ffb6 SK |
298 | ty_opt_ref := Some ty |
299 | | Type.Unit | |
300 | | Type.Nil | |
301 | | Type.Int | |
302 | | Type.String | |
303 | | Type.Record _ | |
304 | | Type.Array _ -> | |
305 | () | |
306 | ) | |
307 | ); | |
308 | env | |
76c771a7 SK |
309 | | A.FunDecs fundecs -> |
310 | List.fold_left fundecs ~init:env ~f:( | |
311 | fun env (A.FunDec {name; params; result; body; pos=_}) -> | |
312 | let (env_for_body, formals_in_reverse_order) = | |
313 | List.fold_left params ~init:(env, []) ~f:( | |
314 | fun (env, formals) (A.Field {name; escape=_; typ; pos}) -> | |
cbb4ffb6 | 315 | let ty = env_get_typ_actual ~env ~sym:typ ~pos in |
76c771a7 SK |
316 | let env = Env.set_val env name (Value.Var {ty}) in |
317 | (env, ty :: formals) | |
318 | ) | |
319 | in | |
320 | (* ignore because we only care if an exception is raised *) | |
321 | ignore (transExp ~env:env_for_body body); | |
322 | let formals = List.rev formals_in_reverse_order in | |
323 | let result = | |
324 | match result with | |
325 | | None -> | |
326 | Type.Unit | |
327 | | Some (sym, pos) -> | |
cbb4ffb6 | 328 | env_get_typ_actual ~sym ~env ~pos |
76c771a7 SK |
329 | in |
330 | Env.set_val env name (Value.Fun {formals; result}) | |
331 | ) | |
8744eb3a | 332 | ) |
cbb4ffb6 SK |
333 | and transTy ~(env : Env.t) (ty_exp : A.ty) : Type.t = |
334 | (match ty_exp with | |
0324a942 SK |
335 | | A.NameTy {symbol=sym; pos} -> |
336 | env_get_typ ~sym ~env ~pos | |
337 | | A.RecordTy fields -> | |
338 | let fields = | |
339 | List.map fields ~f:(fun (A.Field {name; escape=_; typ; pos}) -> | |
340 | let ty = env_get_typ ~sym:typ ~env ~pos in | |
341 | (name, ty) | |
342 | ) | |
343 | in | |
344 | Type.new_record fields | |
345 | | A.ArrayTy {symbol=sym; pos} -> | |
346 | let element_ty = env_get_typ ~sym ~env ~pos in | |
347 | Type.new_array element_ty | |
348 | ) | |
155ee327 SK |
349 | end |
350 | ||
8744eb3a SK |
351 | open Semant |
352 | ||
155ee327 | 353 | let transProg absyn = |
155ee327 SK |
354 | let {exp = _; ty = _} = transExp absyn ~env:Env.base in |
355 | () |