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523e2b06 SK |
1 | module List = ListLabels |
2 | ||
155ee327 | 3 | module A = Tiger_absyn |
e6e82c08 | 4 | module Dag = Tiger_dag |
155ee327 SK |
5 | module Env = Tiger_env |
6 | module E = Tiger_error | |
e6e82c08 SK |
7 | module Pos = Tiger_position |
8 | module Sym = Tiger_symbol | |
155ee327 SK |
9 | module Translate = Tiger_translate |
10 | module Type = Tiger_env_type | |
11 | module Value = Tiger_env_value | |
12 | ||
13 | (* The only reason for having this seemingly-superfluous inner module is to | |
14 | * have this nice signature as a summary of what each function does. *) | |
15 | module Semant : sig | |
16 | type expty = | |
17 | { exp : Translate.exp | |
18 | ; ty : Type.t | |
19 | } | |
20 | ||
21 | (* Violating normal naming convention just to make it easier to follow | |
22 | * Appel's | |
23 | *) | |
24 | val transExp : env:Env.t -> A.exp -> expty | |
862e5c05 SK |
25 | |
26 | (* transVar does not seem to be needed, as trvar handles all our cases. | |
27 | * Am I wrong? | |
28 | * | |
29 | * val transVar : env:Env.t -> A.var -> expty | |
30 | * | |
31 | *) | |
155ee327 SK |
32 | end = struct |
33 | type expty = | |
34 | { exp : Translate.exp | |
35 | ; ty : Type.t | |
36 | } | |
37 | ||
cbb4ffb6 SK |
38 | let rec actual_ty ty ~pos = |
39 | match ty with | |
40 | | Type.Name (name, ty_opt_ref) -> | |
41 | (match !ty_opt_ref with | |
42 | | None -> | |
43 | E.raise (E.Unknown_type {ty_id=name; pos}) | |
44 | | Some ty -> | |
45 | actual_ty ty ~pos | |
46 | ) | |
47 | | Type.Unit | |
48 | | Type.Nil | |
49 | | Type.Int | |
50 | | Type.String | |
51 | | Type.Record _ | |
52 | | Type.Array _ -> | |
53 | ty | |
54 | ||
523e2b06 SK |
55 | let return ty = {exp = (); ty} |
56 | let return_unit = return Type.Unit | |
57 | let return_nil = return Type.Nil | |
58 | let return_int = return Type.Int | |
59 | let return_string = return Type.String | |
155ee327 | 60 | |
523e2b06 SK |
61 | let env_get_typ ~sym ~env ~pos : Type.t = |
62 | match Env.get_typ env sym with | |
63 | | Some ty -> ty | |
64 | | None -> E.raise (E.Unknown_type {ty_id=sym; pos}) | |
65 | ||
cbb4ffb6 SK |
66 | let env_get_typ_actual ~sym ~env ~pos : Type.t = |
67 | actual_ty (env_get_typ ~sym ~env ~pos) ~pos | |
68 | ||
523e2b06 SK |
69 | let env_get_val ~sym ~env ~pos : Value.t = |
70 | match Env.get_val env sym with | |
71 | | Some ty -> ty | |
72 | | None -> E.raise (E.Unknown_id {id=sym; pos}) | |
73 | ||
74 | let check_same {exp=_; ty=ty_left} {exp=_; ty=ty_right} ~pos : unit = | |
75 | if Type.is_equal ty_left ty_right then | |
76 | () | |
77 | else | |
78 | E.raise (E.Wrong_type {expected=ty_left; given=ty_right; pos}) | |
79 | ||
80 | let check_int expty ~pos : unit = | |
cbb4ffb6 | 81 | check_same return_int expty ~pos |
978cb41c | 82 | |
e6e82c08 SK |
83 | let paths_of_typedecs typedecs : (Sym.t * Sym.t * Pos.t) list list = |
84 | let (path, paths) = | |
85 | List.fold_left typedecs ~init:([], []) ~f:( | |
86 | fun (path, paths) (A.TypeDec {name=child; ty; pos}) -> | |
87 | match ty with | |
88 | | A.NameTy {symbol=parent; _} -> | |
89 | (((parent, child, pos) :: path), paths) | |
90 | | A.RecordTy _ | |
91 | | A.ArrayTy _ -> | |
92 | ([], path :: paths) | |
93 | ) | |
94 | in | |
95 | List.map (path :: paths) ~f:List.rev | |
96 | ||
97 | let check_cycles (typedecs : A.typedec list) : unit = | |
98 | let non_empty_paths = | |
99 | List.filter | |
100 | (paths_of_typedecs typedecs) | |
101 | ~f:(function [] -> false | _ -> true) | |
102 | in | |
103 | List.iter non_empty_paths ~f:( | |
104 | fun path -> | |
105 | match Dag.of_list (List.map path ~f:(fun (p, c, _) -> (p, c))) with | |
106 | | Ok _ -> | |
107 | () | |
108 | | Error `Cycle -> | |
109 | let (_, from_id, from_pos) = List.hd path in | |
110 | let (_, to_id, to_pos) = List.hd (List.rev path) in | |
111 | E.raise (E.Cycle_in_type_decs {from_id; from_pos; to_id; to_pos}) | |
112 | ) | |
113 | ||
523e2b06 SK |
114 | let rec transExp ~env exp = |
115 | let rec trexp exp = | |
116 | (match exp with | |
117 | | A.NilExp -> | |
118 | return_nil | |
119 | | A.IntExp _ -> | |
120 | return_int | |
121 | | A.StringExp {string=_; _} -> | |
122 | return_string | |
978cb41c SK |
123 | | A.CallExp {func; args; pos} -> |
124 | (match env_get_val ~sym:func ~env ~pos with | |
125 | | Value.Fun {formals; result} -> | |
54e838f4 SK |
126 | let expected = List.length formals in |
127 | let given = List.length args in | |
128 | if given = expected then | |
129 | begin | |
130 | List.iter2 formals args ~f:(fun ty_expected exp_given -> | |
131 | check_same | |
132 | (return (actual_ty ~pos ty_expected)) | |
133 | (trexp exp_given) | |
134 | ~pos; | |
135 | ); | |
136 | return (actual_ty ~pos result) | |
137 | end | |
138 | else | |
139 | E.raise (E.Wrong_number_of_args {func; expected; given; pos}) | |
978cb41c SK |
140 | | Value.Var _ -> |
141 | E.raise (E.Id_not_a_function {id=func; pos}) | |
142 | ) | |
523e2b06 SK |
143 | | A.OpExp {oper; left; right; pos} -> |
144 | trop oper ~left ~right ~pos | |
0ed7a07c | 145 | | A.RecordExp {fields=field_exps; typ; pos} -> |
cbb4ffb6 | 146 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
0ed7a07c SK |
147 | Type.if_record |
148 | ty | |
149 | ~f:(fun field_tys -> | |
150 | List.iter field_exps ~f:(fun (field, exp, pos) -> | |
151 | (match List.assoc_opt field field_tys with | |
152 | | Some field_ty -> | |
cbb4ffb6 | 153 | check_same (return (actual_ty ~pos field_ty)) (trexp exp) ~pos |
0ed7a07c SK |
154 | | None -> |
155 | E.raise | |
156 | (E.No_such_field_in_record {field; record=ty; pos}) | |
157 | ) | |
158 | ) | |
159 | ) | |
160 | ~otherwise:(fun () -> | |
161 | E.raise (E.Wrong_type_used_as_record {ty_id=typ; ty; pos}) | |
162 | ); | |
cbb4ffb6 | 163 | return (actual_ty ~pos ty) |
9d8471b2 | 164 | | A.SeqExp [] -> |
523e2b06 | 165 | return_unit |
9d8471b2 SK |
166 | | A.SeqExp exps -> |
167 | let last xs = | |
168 | xs | |
169 | |> List.rev (* Yes, redundant, but clean-looking ;-P *) | |
170 | |> List.hd (* Empty is matched in above SeqExp match case *) | |
171 | in | |
172 | exps | |
cbb4ffb6 | 173 | |> List.map ~f:(fun (exp, _) -> trexp exp) |
9d8471b2 | 174 | |> last |
523e2b06 SK |
175 | | A.AssignExp {var; exp; pos} -> |
176 | check_same (trvar var) (trexp exp) ~pos; | |
177 | (* TODO: Add var->exp to val env? *) | |
178 | return_unit | |
179 | | A.IfExp {test; then'; else'; pos} -> | |
180 | (* test : must be int, because we have no bool *) | |
181 | (* then : must equal else *) | |
182 | (* else : must equal then or be None *) | |
183 | check_int (trexp test) ~pos; | |
184 | (match (trexp then', else') with | |
185 | | expty_then, None -> | |
186 | expty_then | |
187 | | expty_then, Some else' -> | |
188 | let expty_else = trexp else' in | |
189 | check_same expty_then expty_else ~pos; | |
190 | expty_then | |
191 | ) | |
192 | | A.WhileExp {test; body; pos} -> | |
193 | (* test : must be int, because we have no bool *) | |
194 | check_int (trexp test) ~pos; | |
195 | ignore (trexp body); (* Only care if a type-error is raised *) | |
196 | return_unit | |
197 | | A.ForExp {var; lo; hi; body; pos; escape=_} -> | |
198 | check_int (trexp lo) ~pos; | |
199 | check_int (trexp hi) ~pos; | |
200 | (* Only care if a type-error is raised *) | |
85e08b69 SK |
201 | let env = Env.set_val env var (Value.Var {ty = Type.Int}) in |
202 | ignore (transExp ~env body); | |
523e2b06 SK |
203 | return_unit |
204 | | A.BreakExp _ -> | |
205 | return_unit | |
8744eb3a SK |
206 | | A.LetExp {decs; body; pos=_} -> |
207 | (* (1) decs augment env *) | |
208 | (* (2) body checked against the new env *) | |
209 | let env = | |
210 | List.fold_left decs ~init:env ~f:(fun env dec -> transDec dec ~env) | |
211 | in | |
212 | transExp body ~env | |
4c550cd5 SK |
213 | | A.ArrayExp {typ; size; init; pos} -> |
214 | check_int (trexp size) ~pos; | |
cbb4ffb6 | 215 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
4c550cd5 SK |
216 | Type.if_array |
217 | ty | |
218 | ~f:(fun ty_elements -> | |
cbb4ffb6 | 219 | check_same (return (actual_ty ~pos ty_elements)) (trexp init) ~pos |
4c550cd5 SK |
220 | ) |
221 | ~otherwise:(fun () -> | |
222 | E.raise (E.Wrong_type_used_as_array {ty_id=typ; ty; pos}) | |
223 | ); | |
cbb4ffb6 | 224 | return (actual_ty ~pos ty) |
523e2b06 SK |
225 | | A.VarExp var -> |
226 | trvar var | |
227 | ) | |
228 | and trvar = | |
229 | (function | |
230 | | A.SimpleVar {symbol=sym; pos} -> | |
231 | (match env_get_val ~sym ~env ~pos with | |
232 | | Value.Fun _ -> E.raise (E.Id_is_a_function {id=sym; pos}) | |
cbb4ffb6 | 233 | | Value.Var {ty} -> return (actual_ty ~pos ty) |
523e2b06 SK |
234 | ) |
235 | | A.FieldVar {var; symbol; pos} -> | |
236 | let {exp=_; ty} = trvar var in | |
237 | Type.if_record | |
238 | ty | |
239 | ~f:(fun fields -> | |
240 | (match List.assoc_opt symbol fields with | |
241 | | None -> | |
242 | E.raise | |
243 | (E.No_such_field_in_record {field=symbol; record=ty; pos}) | |
244 | | Some ty -> | |
cbb4ffb6 | 245 | return (actual_ty ~pos ty) |
523e2b06 SK |
246 | ) |
247 | ) | |
248 | ~otherwise:(fun () -> E.raise (E.Exp_not_a_record {ty; pos})) | |
161a300d SK |
249 | | A.SubscriptVar {var; exp; pos} -> |
250 | let {exp=_; ty} = trvar var in | |
251 | check_int (trexp exp) ~pos; | |
252 | Type.if_array | |
253 | ty | |
cbb4ffb6 | 254 | ~f:(fun ty_elements -> return (actual_ty ~pos ty_elements)) |
161a300d | 255 | ~otherwise:(fun () -> E.raise (E.Exp_not_an_array {ty; pos})) |
523e2b06 SK |
256 | ) |
257 | and trop oper ~left ~right ~pos = | |
cbb4ffb6 | 258 | (* TODO: Refactor trop - all opers return bool/int *) |
523e2b06 SK |
259 | let expty_left = trexp left in |
260 | let expty_right = trexp right in | |
261 | check_same expty_left expty_right ~pos; | |
262 | let {exp=_; ty} = expty_left in | |
263 | let module T = Type in | |
264 | (match oper with | |
265 | (* Arithmetic: int *) | |
266 | | A.PlusOp | |
267 | | A.MinusOp | |
268 | | A.TimesOp | |
269 | | A.DivideOp -> | |
270 | check_int expty_left ~pos; | |
271 | return_int | |
272 | (* Equality: int, string, array, record *) | |
273 | | A.EqOp | |
274 | | A.NeqOp -> | |
275 | if (T.is_int ty) | |
276 | || (T.is_string ty) | |
277 | || (T.is_array ty) | |
278 | || (T.is_record ty) | |
279 | then | |
cbb4ffb6 | 280 | return_int (* Because we have no bool type *) |
523e2b06 SK |
281 | else |
282 | E.raise (E.Invalid_operand_type | |
283 | { oper | |
284 | ; valid = ["int"; "string"; "array"; "record"] | |
285 | ; given = ty | |
286 | ; pos | |
287 | }) | |
288 | (* Order: int, string *) | |
289 | | A.LtOp | |
290 | | A.LeOp | |
291 | | A.GtOp | |
292 | | A.GeOp -> | |
293 | if (T.is_int ty) | |
294 | || (T.is_string ty) | |
295 | then | |
cbb4ffb6 | 296 | return_int (* Because we have no bool type *) |
523e2b06 SK |
297 | else |
298 | E.raise (E.Invalid_operand_type | |
299 | { oper | |
300 | ; valid = ["int"; "string"] | |
301 | ; given = ty | |
302 | ; pos | |
303 | }) | |
304 | ) | |
305 | in | |
306 | trexp exp | |
862e5c05 | 307 | and transDec ~(env : Env.t) (dec : A.dec) : Env.t = |
8744eb3a SK |
308 | (match dec with |
309 | | A.VarDec {name; typ=typ_opt; init; pos=pos_outter; escape=_} -> | |
310 | let ty = | |
311 | (match (typ_opt, transExp ~env init) with | |
312 | | None, {ty; exp=()} -> | |
313 | ty | |
314 | | Some (sym, pos_inner), expty_init -> | |
cbb4ffb6 SK |
315 | let ty = env_get_typ_actual ~sym ~env ~pos:pos_inner in |
316 | check_same (return ty) expty_init ~pos:pos_outter; | |
8744eb3a SK |
317 | ty |
318 | ) | |
319 | in | |
320 | Env.set_val env name (Value.Var {ty}) | |
0324a942 | 321 | | A.TypeDecs typedecs -> |
e6e82c08 | 322 | check_cycles typedecs; |
cbb4ffb6 SK |
323 | let env = |
324 | List.fold_left typedecs ~init:env ~f:( | |
325 | fun env (A.TypeDec {name; ty=_; pos=_}) -> | |
326 | Env.set_typ env name (Type.Name (name, ref None)) | |
327 | ) | |
328 | in | |
329 | List.iter typedecs ~f:(fun (A.TypeDec {name; ty=ty_exp; pos}) -> | |
330 | let ty = transTy ~env ty_exp in | |
331 | (match env_get_typ ~sym:name ~env ~pos with | |
9340b0e3 | 332 | | Type.Name (_, ty_opt_ref) -> |
cbb4ffb6 SK |
333 | ty_opt_ref := Some ty |
334 | | Type.Unit | |
335 | | Type.Nil | |
336 | | Type.Int | |
337 | | Type.String | |
338 | | Type.Record _ | |
339 | | Type.Array _ -> | |
340 | () | |
341 | ) | |
342 | ); | |
343 | env | |
76c771a7 | 344 | | A.FunDecs fundecs -> |
a284f5c2 SK |
345 | let env_with_fun_heads_only = |
346 | List.fold_left fundecs ~init:env ~f:( | |
347 | fun env (A.FunDec {name; params; result; body=_; pos=_}) -> | |
348 | let formals = | |
349 | List.map params ~f:( | |
350 | fun (A.Field {name=_; typ; pos; escape=_}) -> | |
351 | env_get_typ_actual ~env ~sym:typ ~pos | |
352 | ) | |
353 | in | |
354 | let result = | |
355 | match result with | |
356 | | Some (s, p) -> env_get_typ_actual ~sym:s ~env ~pos:p | |
357 | | None -> Type.Unit | |
358 | in | |
359 | Env.set_val env name (Value.Fun {formals; result}) | |
360 | ) | |
361 | in | |
362 | List.iter fundecs ~f:( | |
363 | fun (A.FunDec {name=_; params; result=_; body; pos=_}) -> | |
364 | let env_with_fun_heads_and_local_vars = | |
365 | List.fold_left params ~init:env_with_fun_heads_only ~f:( | |
366 | fun env (A.Field {name=var_name; escape=_; typ; pos}) -> | |
367 | let var_ty = env_get_typ_actual ~env ~sym:typ ~pos in | |
368 | Env.set_val env var_name (Value.Var {ty = var_ty}) | |
76c771a7 SK |
369 | ) |
370 | in | |
a284f5c2 SK |
371 | (* we only care if an exception is raised *) |
372 | ignore (transExp ~env:env_with_fun_heads_and_local_vars body); | |
373 | ); | |
374 | env_with_fun_heads_only | |
8744eb3a | 375 | ) |
cbb4ffb6 SK |
376 | and transTy ~(env : Env.t) (ty_exp : A.ty) : Type.t = |
377 | (match ty_exp with | |
0324a942 SK |
378 | | A.NameTy {symbol=sym; pos} -> |
379 | env_get_typ ~sym ~env ~pos | |
380 | | A.RecordTy fields -> | |
381 | let fields = | |
382 | List.map fields ~f:(fun (A.Field {name; escape=_; typ; pos}) -> | |
383 | let ty = env_get_typ ~sym:typ ~env ~pos in | |
384 | (name, ty) | |
385 | ) | |
386 | in | |
387 | Type.new_record fields | |
388 | | A.ArrayTy {symbol=sym; pos} -> | |
389 | let element_ty = env_get_typ ~sym ~env ~pos in | |
390 | Type.new_array element_ty | |
391 | ) | |
155ee327 SK |
392 | end |
393 | ||
8744eb3a SK |
394 | open Semant |
395 | ||
155ee327 | 396 | let transProg absyn = |
155ee327 SK |
397 | let {exp = _; ty = _} = transExp absyn ~env:Env.base in |
398 | () |