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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} -> | |
93 | List.iter2 formals args ~f:(fun ty_expected exp_given -> | |
cbb4ffb6 | 94 | check_same (return (actual_ty ~pos ty_expected)) (trexp exp_given) ~pos; |
978cb41c | 95 | ); |
cbb4ffb6 | 96 | return (actual_ty ~pos result) |
978cb41c SK |
97 | | Value.Var _ -> |
98 | E.raise (E.Id_not_a_function {id=func; pos}) | |
99 | ) | |
523e2b06 SK |
100 | | A.OpExp {oper; left; right; pos} -> |
101 | trop oper ~left ~right ~pos | |
0ed7a07c | 102 | | A.RecordExp {fields=field_exps; typ; pos} -> |
cbb4ffb6 | 103 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
0ed7a07c SK |
104 | Type.if_record |
105 | ty | |
106 | ~f:(fun field_tys -> | |
107 | List.iter field_exps ~f:(fun (field, exp, pos) -> | |
108 | (match List.assoc_opt field field_tys with | |
109 | | Some field_ty -> | |
cbb4ffb6 | 110 | check_same (return (actual_ty ~pos field_ty)) (trexp exp) ~pos |
0ed7a07c SK |
111 | | None -> |
112 | E.raise | |
113 | (E.No_such_field_in_record {field; record=ty; pos}) | |
114 | ) | |
115 | ) | |
116 | ) | |
117 | ~otherwise:(fun () -> | |
118 | E.raise (E.Wrong_type_used_as_record {ty_id=typ; ty; pos}) | |
119 | ); | |
cbb4ffb6 | 120 | return (actual_ty ~pos ty) |
9d8471b2 | 121 | | A.SeqExp [] -> |
523e2b06 | 122 | return_unit |
9d8471b2 SK |
123 | | A.SeqExp exps -> |
124 | let last xs = | |
125 | xs | |
126 | |> List.rev (* Yes, redundant, but clean-looking ;-P *) | |
127 | |> List.hd (* Empty is matched in above SeqExp match case *) | |
128 | in | |
129 | exps | |
cbb4ffb6 | 130 | |> List.map ~f:(fun (exp, _) -> trexp exp) |
9d8471b2 | 131 | |> last |
523e2b06 SK |
132 | | A.AssignExp {var; exp; pos} -> |
133 | check_same (trvar var) (trexp exp) ~pos; | |
134 | (* TODO: Add var->exp to val env? *) | |
135 | return_unit | |
136 | | A.IfExp {test; then'; else'; pos} -> | |
137 | (* test : must be int, because we have no bool *) | |
138 | (* then : must equal else *) | |
139 | (* else : must equal then or be None *) | |
140 | check_int (trexp test) ~pos; | |
141 | (match (trexp then', else') with | |
142 | | expty_then, None -> | |
143 | expty_then | |
144 | | expty_then, Some else' -> | |
145 | let expty_else = trexp else' in | |
146 | check_same expty_then expty_else ~pos; | |
147 | expty_then | |
148 | ) | |
149 | | A.WhileExp {test; body; pos} -> | |
150 | (* test : must be int, because we have no bool *) | |
151 | check_int (trexp test) ~pos; | |
152 | ignore (trexp body); (* Only care if a type-error is raised *) | |
153 | return_unit | |
154 | | A.ForExp {var; lo; hi; body; pos; escape=_} -> | |
155 | check_int (trexp lo) ~pos; | |
156 | check_int (trexp hi) ~pos; | |
157 | (* Only care if a type-error is raised *) | |
85e08b69 SK |
158 | let env = Env.set_val env var (Value.Var {ty = Type.Int}) in |
159 | ignore (transExp ~env body); | |
523e2b06 SK |
160 | return_unit |
161 | | A.BreakExp _ -> | |
162 | return_unit | |
8744eb3a SK |
163 | | A.LetExp {decs; body; pos=_} -> |
164 | (* (1) decs augment env *) | |
165 | (* (2) body checked against the new env *) | |
166 | let env = | |
167 | List.fold_left decs ~init:env ~f:(fun env dec -> transDec dec ~env) | |
168 | in | |
169 | transExp body ~env | |
4c550cd5 SK |
170 | | A.ArrayExp {typ; size; init; pos} -> |
171 | check_int (trexp size) ~pos; | |
cbb4ffb6 | 172 | let ty = env_get_typ_actual ~sym:typ ~env ~pos in |
4c550cd5 SK |
173 | Type.if_array |
174 | ty | |
175 | ~f:(fun ty_elements -> | |
cbb4ffb6 | 176 | check_same (return (actual_ty ~pos ty_elements)) (trexp init) ~pos |
4c550cd5 SK |
177 | ) |
178 | ~otherwise:(fun () -> | |
179 | E.raise (E.Wrong_type_used_as_array {ty_id=typ; ty; pos}) | |
180 | ); | |
cbb4ffb6 | 181 | return (actual_ty ~pos ty) |
523e2b06 SK |
182 | | A.VarExp var -> |
183 | trvar var | |
184 | ) | |
185 | and trvar = | |
186 | (function | |
187 | | A.SimpleVar {symbol=sym; pos} -> | |
188 | (match env_get_val ~sym ~env ~pos with | |
189 | | Value.Fun _ -> E.raise (E.Id_is_a_function {id=sym; pos}) | |
cbb4ffb6 | 190 | | Value.Var {ty} -> return (actual_ty ~pos ty) |
523e2b06 SK |
191 | ) |
192 | | A.FieldVar {var; symbol; pos} -> | |
193 | let {exp=_; ty} = trvar var in | |
194 | Type.if_record | |
195 | ty | |
196 | ~f:(fun fields -> | |
197 | (match List.assoc_opt symbol fields with | |
198 | | None -> | |
199 | E.raise | |
200 | (E.No_such_field_in_record {field=symbol; record=ty; pos}) | |
201 | | Some ty -> | |
cbb4ffb6 | 202 | return (actual_ty ~pos ty) |
523e2b06 SK |
203 | ) |
204 | ) | |
205 | ~otherwise:(fun () -> E.raise (E.Exp_not_a_record {ty; pos})) | |
161a300d SK |
206 | | A.SubscriptVar {var; exp; pos} -> |
207 | let {exp=_; ty} = trvar var in | |
208 | check_int (trexp exp) ~pos; | |
209 | Type.if_array | |
210 | ty | |
cbb4ffb6 | 211 | ~f:(fun ty_elements -> return (actual_ty ~pos ty_elements)) |
161a300d | 212 | ~otherwise:(fun () -> E.raise (E.Exp_not_an_array {ty; pos})) |
523e2b06 SK |
213 | ) |
214 | and trop oper ~left ~right ~pos = | |
cbb4ffb6 | 215 | (* TODO: Refactor trop - all opers return bool/int *) |
523e2b06 SK |
216 | let expty_left = trexp left in |
217 | let expty_right = trexp right in | |
218 | check_same expty_left expty_right ~pos; | |
219 | let {exp=_; ty} = expty_left in | |
220 | let module T = Type in | |
221 | (match oper with | |
222 | (* Arithmetic: int *) | |
223 | | A.PlusOp | |
224 | | A.MinusOp | |
225 | | A.TimesOp | |
226 | | A.DivideOp -> | |
227 | check_int expty_left ~pos; | |
228 | return_int | |
229 | (* Equality: int, string, array, record *) | |
230 | | A.EqOp | |
231 | | A.NeqOp -> | |
232 | if (T.is_int ty) | |
233 | || (T.is_string ty) | |
234 | || (T.is_array ty) | |
235 | || (T.is_record ty) | |
236 | then | |
cbb4ffb6 | 237 | return_int (* Because we have no bool type *) |
523e2b06 SK |
238 | else |
239 | E.raise (E.Invalid_operand_type | |
240 | { oper | |
241 | ; valid = ["int"; "string"; "array"; "record"] | |
242 | ; given = ty | |
243 | ; pos | |
244 | }) | |
245 | (* Order: int, string *) | |
246 | | A.LtOp | |
247 | | A.LeOp | |
248 | | A.GtOp | |
249 | | A.GeOp -> | |
250 | if (T.is_int ty) | |
251 | || (T.is_string ty) | |
252 | then | |
cbb4ffb6 | 253 | return_int (* Because we have no bool type *) |
523e2b06 SK |
254 | else |
255 | E.raise (E.Invalid_operand_type | |
256 | { oper | |
257 | ; valid = ["int"; "string"] | |
258 | ; given = ty | |
259 | ; pos | |
260 | }) | |
261 | ) | |
262 | in | |
263 | trexp exp | |
862e5c05 | 264 | and transDec ~(env : Env.t) (dec : A.dec) : Env.t = |
8744eb3a SK |
265 | (match dec with |
266 | | A.VarDec {name; typ=typ_opt; init; pos=pos_outter; escape=_} -> | |
267 | let ty = | |
268 | (match (typ_opt, transExp ~env init) with | |
269 | | None, {ty; exp=()} -> | |
270 | ty | |
271 | | Some (sym, pos_inner), expty_init -> | |
cbb4ffb6 SK |
272 | let ty = env_get_typ_actual ~sym ~env ~pos:pos_inner in |
273 | check_same (return ty) expty_init ~pos:pos_outter; | |
8744eb3a SK |
274 | ty |
275 | ) | |
276 | in | |
277 | Env.set_val env name (Value.Var {ty}) | |
0324a942 | 278 | | A.TypeDecs typedecs -> |
cbb4ffb6 SK |
279 | let env = |
280 | List.fold_left typedecs ~init:env ~f:( | |
281 | fun env (A.TypeDec {name; ty=_; pos=_}) -> | |
282 | Env.set_typ env name (Type.Name (name, ref None)) | |
283 | ) | |
284 | in | |
285 | List.iter typedecs ~f:(fun (A.TypeDec {name; ty=ty_exp; pos}) -> | |
286 | let ty = transTy ~env ty_exp in | |
287 | (match env_get_typ ~sym:name ~env ~pos with | |
288 | | Type.Name (name, ty_opt_ref) -> | |
289 | ty_opt_ref := Some ty | |
290 | | Type.Unit | |
291 | | Type.Nil | |
292 | | Type.Int | |
293 | | Type.String | |
294 | | Type.Record _ | |
295 | | Type.Array _ -> | |
296 | () | |
297 | ) | |
298 | ); | |
299 | env | |
76c771a7 SK |
300 | | A.FunDecs fundecs -> |
301 | List.fold_left fundecs ~init:env ~f:( | |
302 | fun env (A.FunDec {name; params; result; body; pos=_}) -> | |
303 | let (env_for_body, formals_in_reverse_order) = | |
304 | List.fold_left params ~init:(env, []) ~f:( | |
305 | fun (env, formals) (A.Field {name; escape=_; typ; pos}) -> | |
cbb4ffb6 | 306 | let ty = env_get_typ_actual ~env ~sym:typ ~pos in |
76c771a7 SK |
307 | let env = Env.set_val env name (Value.Var {ty}) in |
308 | (env, ty :: formals) | |
309 | ) | |
310 | in | |
311 | (* ignore because we only care if an exception is raised *) | |
312 | ignore (transExp ~env:env_for_body body); | |
313 | let formals = List.rev formals_in_reverse_order in | |
314 | let result = | |
315 | match result with | |
316 | | None -> | |
317 | Type.Unit | |
318 | | Some (sym, pos) -> | |
cbb4ffb6 | 319 | env_get_typ_actual ~sym ~env ~pos |
76c771a7 SK |
320 | in |
321 | Env.set_val env name (Value.Fun {formals; result}) | |
322 | ) | |
8744eb3a | 323 | ) |
cbb4ffb6 SK |
324 | and transTy ~(env : Env.t) (ty_exp : A.ty) : Type.t = |
325 | (match ty_exp with | |
0324a942 SK |
326 | | A.NameTy {symbol=sym; pos} -> |
327 | env_get_typ ~sym ~env ~pos | |
328 | | A.RecordTy fields -> | |
329 | let fields = | |
330 | List.map fields ~f:(fun (A.Field {name; escape=_; typ; pos}) -> | |
331 | let ty = env_get_typ ~sym:typ ~env ~pos in | |
332 | (name, ty) | |
333 | ) | |
334 | in | |
335 | Type.new_record fields | |
336 | | A.ArrayTy {symbol=sym; pos} -> | |
337 | let element_ty = env_get_typ ~sym ~env ~pos in | |
338 | Type.new_array element_ty | |
339 | ) | |
155ee327 SK |
340 | end |
341 | ||
8744eb3a SK |
342 | open Semant |
343 | ||
155ee327 | 344 | let transProg absyn = |
155ee327 SK |
345 | let {exp = _; ty = _} = transExp absyn ~env:Env.base in |
346 | () |