Source file lazy_interp.ml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
open Catala_utils
open Shared_ast
let log fmt = Format.ifprintf Format.err_formatter (fmt ^^ "@\n")
let error e = Message.error ~pos:(Expr.pos e)
let noassert = true
type laziness_level = {
eval_struct : bool;
eval_op : bool;
eval_default : bool;
}
let value_level = { eval_struct = false; eval_op = true; eval_default = true }
module Env = struct
type 'm t =
| Env of ((dcalc, 'm) gexpr, ((dcalc, 'm) gexpr * 'm t) ref) Var.Map.t
let find v (Env t) = Var.Map.find v t
let add v e e_env (Env t) = Env (Var.Map.add v (ref (e, e_env)) t)
let empty = Env Var.Map.empty
let join (Env t1) (Env t2) =
Env
(Var.Map.union
(fun _ x1 x2 ->
assert (x1 == x2);
Some x1)
t1 t2)
let print ppf (Env t) =
Format.pp_print_list ~pp_sep:Format.pp_print_space
(fun ppf v -> Print.var_debug ppf v)
ppf (Var.Map.keys t)
end
let rec lazy_eval :
decl_ctx ->
'm Env.t ->
laziness_level ->
(dcalc, 'm) gexpr ->
(dcalc, 'm) gexpr * 'm Env.t =
fun ctx env llevel e0 ->
let eval_to_value ?(eval_default = true) env e =
lazy_eval ctx env { value_level with eval_default } e
in
match e0 with
| EVar v, _ ->
if not llevel.eval_default then e0, env
else
let v_env =
try Env.find v env
with Var.Map.Not_found _ ->
error e0 "Variable %a undefined [@[<hv>%a@]]" Print.var_debug v
Env.print env
in
let e, env1 = !v_env in
let r, env1 = lazy_eval ctx env1 llevel e in
if not (Expr.equal e r) then (
log "@[<hv 2>{{%a =@ [%a]@ ==> [%a]}}@]" Print.var_debug v
(Print.expr ~debug:true ())
e
(Print.expr ~debug:true ())
r;
v_env := r, env1);
r, Env.join env env1
| EAppOp { op; args; tys }, m ->
if
(not llevel.eval_default)
&& not (List.equal Expr.equal args [ELit LUnit, m])
then e0, env
else
let env, args =
List.fold_left_map
(fun env e ->
let e, env = lazy_eval ctx env llevel e in
env, e)
env args
in
if not llevel.eval_op then (EAppOp { op; args; tys }, m), env
else
let renv = ref env in
let eval e =
let e, env = lazy_eval ctx !renv llevel e in
renv := env;
e
in
( Interpreter.evaluate_operator eval op m Global.En
args,
!renv )
| EApp { f; args; tys }, m -> (
if
(not llevel.eval_default)
&& not (List.equal Expr.equal args [ELit LUnit, m])
then e0, env
else
match eval_to_value env f with
| (EAbs { binder; _ }, _), env ->
let vars, body = Bindlib.unmbind binder in
log "@[<v 2>@[<hov 4>{";
let env =
Seq.fold_left2
(fun env1 var e ->
log "@[<hov 2>LET %a = %a@]@ " Print.var_debug var
(Print.expr ~debug:true ())
e;
Env.add var e env env1)
env (Array.to_seq vars) (List.to_seq args)
in
log "@]@[<hov 4>IN [%a]@]" (Print.expr ~debug:true ()) body;
let e, env = lazy_eval ctx env llevel body in
log "@]}";
e, env
| e, _ -> error e "Invalid apply on %a" Expr.format e)
| (EAbs _ | ELit _ | EEmpty), _ -> e0, env
| (EStruct _ | ETuple _ | EInj _ | EArray _), _ ->
if not llevel.eval_struct then e0, env
else
let env, e =
Expr.map_gather ~acc:env ~join:Env.join
~f:(fun e ->
let e, env = lazy_eval ctx env llevel e in
env, Expr.box e)
e0
in
Expr.unbox e, env
| EStructAccess { e; name; field }, _ -> (
if not llevel.eval_default then e0, env
else
match eval_to_value env e with
| (EStruct { name = n; fields }, _), env when StructName.equal name n ->
lazy_eval ctx env llevel (StructField.Map.find field fields)
| e, _ -> error e "Invalid field access on %a" Expr.format e)
| ETupleAccess { e; index; size }, _ -> (
if not llevel.eval_default then e0, env
else
match eval_to_value env e with
| (ETuple es, _), env when List.length es = size ->
lazy_eval ctx env llevel (List.nth es index)
| e, _ -> error e "Invalid tuple access on %a" Expr.format e)
| EMatch { e; name; cases }, _ -> (
if not llevel.eval_default then e0, env
else
match eval_to_value env e with
| (EInj { name = n; cons; e }, m), env when EnumName.equal name n ->
lazy_eval ctx env llevel
( EApp
{ f = EnumConstructor.Map.find cons cases; args = [e]; tys = [] },
m )
| e, _ -> error e "Invalid match argument %a" Expr.format e)
| EDefault { excepts; just; cons }, m -> (
let excs =
List.filter_map
(fun e ->
match eval_to_value env e ~eval_default:false with
| (EEmpty, _), _ -> None
| e -> Some e)
excepts
in
match excs with
| [] -> (
match eval_to_value env just with
| (ELit (LBool true), _), _ -> lazy_eval ctx env llevel cons
| (ELit (LBool false), _), _ -> (EEmpty, m), env
| e, _ -> error e "Invalid exception justification %a" Expr.format e)
| [(e, env)] ->
log "@[<hov 5>EVAL %a@]" Expr.format e;
lazy_eval ctx env llevel e
| _ :: _ :: _ ->
Message.error ~pos:(Expr.mark_pos m)
~extra_pos:(List.map (fun (e, _) -> "", Expr.pos e) excs)
"Conflicting exceptions")
| EPureDefault e, _ -> lazy_eval ctx env llevel e
| EIfThenElse { cond; etrue; efalse }, _ -> (
match eval_to_value env cond with
| (ELit (LBool true), _), _ -> lazy_eval ctx env llevel etrue
| (ELit (LBool false), _), _ -> lazy_eval ctx env llevel efalse
| e, _ -> error e "Invalid condition %a" Expr.format e)
| EErrorOnEmpty e, _ -> (
match eval_to_value env e ~eval_default:false with
| ((EEmpty, _) as e'), _ ->
error e' "This value is undefined %a" Expr.format e
| e, env -> lazy_eval ctx env llevel e)
| EAssert e, m -> (
if noassert then (ELit LUnit, m), env
else
match eval_to_value env e with
| (ELit (LBool true), m), env -> (ELit LUnit, m), env
| (ELit (LBool false), _), _ ->
error e "Assert failure (%a)" Expr.format e
| _ -> error e "Invalid assertion condition %a" Expr.format e)
| EFatalError err, m ->
error e0 "%a" Format.pp_print_text (Runtime.error_message err)
| EExternal _, _ -> assert false
| _ -> .
let interpret_program (prg : ('dcalc, 'm) gexpr program) (scope : ScopeName.t) :
('t, 'm) gexpr * 'm Env.t =
let ctx = prg.decl_ctx in
let (all_env, scopes), () =
BoundList.fold_left prg.code_items ~init:(Env.empty, ScopeName.Map.empty)
~f:(fun (env, scopes) item v ->
match item with
| ScopeDef (name, body) ->
let e = Scope.to_expr ctx body in
( Env.add v (Expr.unbox e) env env,
ScopeName.Map.add name (v, body.scope_body_input_struct) scopes )
| Topdef (_, _, e) -> Env.add v e env env, scopes)
in
let scope_v, scope_arg_struct = ScopeName.Map.find scope scopes in
let { contents = e, env } = Env.find scope_v all_env in
let e = Expr.unbox (Expr.remove_logging_calls e) in
log "=====================";
log "%a" (Print.expr ~debug:true ()) e;
log "=====================";
let m = Mark.get e in
let application_arg =
Expr.estruct ~name:scope_arg_struct
~fields:
(StructField.Map.map
(function
| TArrow (ty_in, ty_out), _ ->
Expr.make_abs
[| Var.make "_" |]
(Bindlib.box EEmpty, Expr.with_ty m ty_out)
ty_in (Expr.mark_pos m)
| ty -> Expr.evar (Var.make "undefined_input") (Expr.with_ty m ty))
(StructName.Map.find scope_arg_struct ctx.ctx_structs))
m
in
let e_app = Expr.eapp ~f:(Expr.box e) ~args:[application_arg] ~tys:[] m in
lazy_eval ctx env
{ value_level with eval_struct = true; eval_op = false }
(Expr.unbox e_app)
let run includes optimize check_invariants ex_scope options =
let prg, _ =
Driver.Passes.dcalc options ~includes ~optimize ~check_invariants
~typed:Expr.typed
in
Interpreter.load_runtime_modules prg;
let scope = Driver.Commands.get_scope_uid prg.decl_ctx ex_scope in
let result_expr, _env = interpret_program prg scope in
let fmt = Format.std_formatter in
Expr.format fmt result_expr
let term =
let open Cmdliner.Term in
const run
$ Cli.Flags.include_dirs
$ Cli.Flags.optimize
$ Cli.Flags.check_invariants
$ Cli.Flags.ex_scope
let () =
Driver.Plugin.register "lazy" term
~doc:"Experimental lazy evaluation (plugin)"