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