2 ||M|| This file is part of HELM, an Hypertextual, Electronic
3 ||A|| Library of Mathematics, developed at the Computer Science
4 ||T|| Department, University of Bologna, Italy.
6 ||T|| HELM is free software; you can redistribute it and/or
7 ||A|| modify it under the terms of the GNU General Public License
8 \ / version 2 or (at your option) any later version.
9 \ / This software is distributed as is, NO WARRANTY.
10 V_______________________________________________________________ *)
14 exception RefineFailure of (Stdpp.location * string) Lazy.t;;
15 exception Uncertain of (Stdpp.location * string) Lazy.t;;
16 exception AssertFailure of string Lazy.t;;
19 module Ref = NReference
22 let inside c = indent := !indent ^ String.make 1 c;;
23 let outside () = indent := String.sub !indent 0 (String.length !indent -1);;
26 prerr_endline (Printf.sprintf "%-20s" !indent ^ " " ^ Lazy.force s)
31 let wrap_exc msg = function
32 | NCicUnification.Uncertain _ -> Uncertain msg
33 | NCicUnification.UnificationFailure _ -> RefineFailure msg
34 | NCicTypeChecker.TypeCheckerFailure _ -> RefineFailure msg
38 let exp_implicit metasenv context expty =
39 let foo x = match expty with Some t -> `WithType t | None -> x in
41 | `Closed -> NCicMetaSubst.mk_meta metasenv [] (foo `Type)
42 | `Type -> NCicMetaSubst.mk_meta metasenv context (foo `Type)
43 | `Term -> NCicMetaSubst.mk_meta metasenv context (foo `Term)
47 let force_to_sort metasenv subst context t =
48 match NCicReduction.whd ~subst context t with
49 | C.Meta (_,(_,(C.Irl 0 | C.Ctx []))) as t ->
51 | C.Meta (i,(_,lc)) as t ->
52 let len = match lc with C.Irl len->len | C.Ctx l->List.length l in
53 let metasenv, subst, _ =
55 NCicMetaSubst.restrict metasenv subst i (HExtlib.list_seq 1 (len+1))
56 else metasenv, subst, 0
59 | C.Sort _ -> metasenv, subst, t
64 localise metasenv subst context orig_s orig_t (name,s) t (t1, t2)
66 let metasenv, subst, t1 = force_to_sort metasenv subst context t1 in
67 let metasenv, subst, t2 =
68 force_to_sort metasenv subst ((name,C.Decl s)::context) t2 in
70 | C.Sort _, C.Sort C.Prop -> metasenv, subst, t2
71 | C.Sort (C.Type u1), C.Sort (C.Type u2) ->
72 metasenv, subst, C.Sort (C.Type (u1@u2))
73 | C.Sort C.Prop,C.Sort (C.Type _) -> metasenv, subst, t2
76 | C.Sort _, C.Meta _ -> metasenv, subst, t2
77 | x, (C.Sort _ | C.Meta _) | _, x ->
78 let y, context, orig =
79 if x == t1 then s, context, orig_s
80 else t, ((name,C.Decl s)::context), orig_t
82 raise (RefineFailure (lazy (localise orig,Printf.sprintf
83 "%s is expected to be a type, but its type is %s that is not a sort"
84 (NCicPp.ppterm ~subst ~metasenv ~context y)
85 (NCicPp.ppterm ~subst ~metasenv ~context x))))
88 let check_allowed_sort_elimination localise r orig =
91 | C.Appl l -> C.Appl (l @ [arg])
92 | t -> C.Appl [t;arg] in
93 (* ctx, ind_type @ lefts, sort_of_ind_ty@lefts, outsort *)
94 let rec aux metasenv subst context ind arity1 arity2 =
95 (*D*)inside 'S'; try let rc =
96 let arity1 = NCicReduction.whd ~subst context arity1 in
98 | C.Prod (name,so1,de1) (* , t ==?== C.Prod _ *) ->
99 let metasenv, meta, _ =
100 NCicMetaSubst.mk_meta metasenv ((name,C.Decl so1)::context) `Typeless
102 let metasenv, subst =
103 try NCicUnification.unify metasenv subst context
104 (C.Prod (name, so1, meta)) arity2
105 with exc -> raise (wrap_exc (lazy (localise orig, Printf.sprintf
106 "expected %s, found %s" (* XXX localizzare meglio *)
107 (NCicPp.ppterm ~subst ~metasenv ~context arity1)
108 (NCicPp.ppterm ~subst ~metasenv ~context arity2))) exc)
110 aux metasenv subst ((name, C.Decl so1)::context)
111 (mkapp (NCicSubstitution.lift 1 ind) (C.Rel 1)) de1 meta
112 | C.Sort _ (* , t ==?== C.Prod _ *) ->
113 let metasenv, meta, _ = NCicMetaSubst.mk_meta metasenv [] `Typeless in
114 let metasenv, subst =
115 try NCicUnification.unify metasenv subst context
116 (C.Prod ("_", ind, meta)) arity2
117 with exc -> raise (wrap_exc (lazy (localise orig, Printf.sprintf
118 "expected %s, found %s" (* XXX localizzare meglio *)
119 (NCicPp.ppterm ~subst ~metasenv ~context arity1)
120 (NCicPp.ppterm ~subst ~metasenv ~context arity2))) exc)
122 (try NCicTypeChecker.check_allowed_sort_elimination
123 ~metasenv ~subst r context ind arity1 arity2;
125 with exc -> raise (wrap_exc (lazy (localise orig,
126 "Sort elimination not allowed ")) exc))
128 (*D*)in outside(); rc with exc -> outside (); raise exc
134 ?(localise=fun _ -> Stdpp.dummy_loc) metasenv subst context term expty
136 let force_ty metasenv subst context orig t infty expty =
137 (*D*)inside 'F'; try let rc =
142 | C.Lambda _ -> metasenv, subst, t, expty
145 (NCicPp.ppterm ~metasenv ~subst ~context infty) ^ " === " ^
146 (NCicPp.ppterm ~metasenv ~subst ~context expty)));
147 let metasenv, subst =
148 try NCicUnification.unify metasenv subst context infty expty
149 with exc -> raise (wrap_exc (lazy (localise orig, Printf.sprintf
150 "The term %s has type %s but is here used with type %s"
151 (NCicPp.ppterm ~metasenv ~subst ~context t)
152 (NCicPp.ppterm ~metasenv ~subst ~context infty)
153 (NCicPp.ppterm ~metasenv ~subst ~context expty))) exc)
155 metasenv, subst, t, expty)
156 | None -> metasenv, subst, t, infty
157 (*D*)in outside(); rc with exc -> outside (); raise exc
159 let rec typeof_aux metasenv subst context expty =
161 (*D*)inside 'R'; try let rc =
162 pp (lazy (NCicPp.ppterm ~metasenv ~subst ~context t));
163 let metasenv, subst, t, infty =
168 match List.nth context (n - 1) with
169 | (_,C.Decl ty) -> NCicSubstitution.lift n ty
170 | (_,C.Def (_,ty)) -> NCicSubstitution.lift n ty
172 raise (RefineFailure (lazy (localise t,"unbound variable"))))
174 metasenv, subst, t, infty
175 | C.Sort (C.Type [false,u]) -> metasenv,subst,t,(C.Sort (C.Type [true, u]))
176 | C.Sort (C.Type _) ->
177 raise (AssertFailure (lazy ("Cannot type an inferred type: "^
178 NCicPp.ppterm ~subst ~metasenv ~context t)))
179 | C.Sort _ -> metasenv,subst,t,(C.Sort (C.Type NCicEnvironment.type0))
180 | C.Implicit infos ->
181 let metasenv,t,ty = exp_implicit metasenv context expty infos in
182 metasenv, subst, t, ty
183 | C.Meta (n,l) as t ->
186 let _,_,_,ty = NCicUtils.lookup_subst n subst in ty
187 with NCicUtils.Subst_not_found _ -> try
188 let _,_,ty = NCicUtils.lookup_meta n metasenv in
189 match ty with C.Implicit _ -> assert false | _ -> ty
190 with NCicUtils.Meta_not_found _ ->
191 raise (AssertFailure (lazy (Printf.sprintf
192 "%s not found" (NCicPp.ppterm ~subst ~metasenv ~context t))))
194 metasenv, subst, t, NCicSubstitution.subst_meta l ty
196 metasenv, subst, t, NCicTypeChecker.typeof ~subst ~metasenv context t
197 | C.Prod (name,(s as orig_s),(t as orig_t)) ->
198 let metasenv, subst, s, s1 = typeof_aux metasenv subst context None s in
199 let context1 = (name,(C.Decl s))::context in
200 let metasenv, subst, t, s2 = typeof_aux metasenv subst context1 None t in
201 let metasenv, subst, ty =
202 sort_of_prod localise metasenv subst
203 context orig_s orig_t (name,s) t (s1,s2)
205 metasenv, subst, NCic.Prod(name,s,t), ty
206 | C.Lambda (n,(s as orig_s),t) ->
207 let exp_s, exp_ty_t =
211 match NCicReduction.whd ~subst context expty with
212 | C.Prod (_,s,t) -> Some s, Some t
215 let metasenv, subst, s, ty_s =
216 typeof_aux metasenv subst context None s in
217 let metasenv, subst, _ = force_to_sort metasenv subst context ty_s in
218 let (metasenv,subst), exp_ty_t =
221 (try NCicUnification.unify metasenv subst context s exp_s,exp_ty_t
222 with exc -> raise (wrap_exc (lazy (localise orig_s, Printf.sprintf
223 "Source type %s was expected to be %s" (NCicPp.ppterm ~metasenv
224 ~subst ~context s) (NCicPp.ppterm ~metasenv ~subst ~context
226 | None -> (metasenv, subst), None
228 (* XXX coerce_to_sort s *)
229 let context = (n,C.Decl s) :: context in
230 let metasenv, subst, t, ty_t =
231 typeof_aux metasenv subst context exp_ty_t t
233 metasenv, subst, C.Lambda(n,s,t), C.Prod (n,s,ty_t)
234 | C.LetIn (n,ty,t,bo) ->
235 let metasenv, subst, ty, ty_ty =
236 typeof_aux metasenv subst context None ty in
237 let metasenv, subst, _ = force_to_sort metasenv subst context ty_ty in
238 let metasenv, subst, t, _ =
239 typeof_aux metasenv subst context (Some ty) t in
240 let context1 = (n, C.Def (t,ty)) :: context in
241 let metasenv, subst, bo, bo_ty =
242 typeof_aux metasenv subst context1 None bo
244 let bo_ty = NCicSubstitution.subst ~avoid_beta_redexes:true t bo_ty in
245 metasenv, subst, C.LetIn (n, ty, t, bo), bo_ty
246 | C.Appl ((he as orig_he)::(_::_ as args)) ->
247 let metasenv, subst, he, ty_he =
248 typeof_aux metasenv subst context None he in
249 eat_prods localise metasenv subst context orig_he he ty_he args
250 | C.Appl _ -> raise (AssertFailure (lazy "Appl of length < 2"))
251 | C.Match (Ref.Ref (_,Ref.Ind (_,tyno,_)) as r,
252 outtype,(term as orig_term),pl) as orig ->
253 let _, leftno, itl, _, _ = NCicEnvironment.get_checked_indtys r in
254 let _, _, arity, cl = List.nth itl tyno in
255 let constructorsno = List.length cl in
256 let _, metasenv, args =
257 NCicMetaSubst.saturate metasenv context arity 0 in
258 let ind = if args = [] then C.Const r else C.Appl (C.Const r::args) in
259 let metasenv, subst, term, _ =
260 typeof_aux metasenv subst context (Some ind) term in
261 let metasenv, subst, outtype, outsort =
262 typeof_aux metasenv subst context None outtype in
263 let parameters, arguments = HExtlib.split_nth leftno args in
264 (* let's control if the sort elimination is allowed: [(I q1 ... qr)|B] *)
266 if parameters = [] then C.Const r
267 else C.Appl ((C.Const r)::parameters) in
268 let metasenv, subst, ind, ind_ty =
269 typeof_aux metasenv subst context None ind in
270 let metasenv, subst =
271 check_allowed_sort_elimination localise r orig_term metasenv subst
272 context ind ind_ty outsort
274 (* let's check if the type of branches are right *)
275 if List.length pl <> constructorsno then
276 raise (RefineFailure (lazy (localise orig,
277 "Wrong number of cases in a match")));
278 let _, metasenv, subst, pl_rev =
280 (fun (j, metasenv, subst, branches) p ->
282 let cons = Ref.mk_constructor j r in
283 if parameters = [] then C.Const cons
284 else C.Appl (C.Const cons::parameters)
286 let metasenv, subst, cons, ty_cons =
287 typeof_aux metasenv subst context None cons in
289 NCicTypeChecker.type_of_branch
290 ~subst context leftno outtype cons ty_cons in
291 let metasenv, subst, p, _ =
292 typeof_aux metasenv subst context (Some ty_branch) p in
293 j+1, metasenv, subst, p :: branches)
294 (1, metasenv, subst, []) pl
297 C.Match (r, outtype, term, List.rev pl_rev),
298 NCicReduction.head_beta_reduce (C.Appl (outtype::arguments@[term]))
299 | C.Match _ -> assert false
301 force_ty metasenv subst context orig t infty expty
302 (*D*)in outside(); rc with exc -> outside (); raise exc
304 typeof_aux metasenv subst context expty term
306 and eat_prods localise metasenv subst context orig_he he ty_he args =
307 (*D*)inside 'E'; try let rc =
308 let rec aux metasenv subst args_so_far ty_he = function
309 | [] -> metasenv, subst, NCic.Appl (he :: List.rev args_so_far), ty_he
311 match NCicReduction.whd ~subst context ty_he with
313 let metasenv, subst, arg, _ =
314 typeof ~localise metasenv subst context arg (Some s) in
315 let t = NCicSubstitution.subst ~avoid_beta_redexes:true arg t in
316 aux metasenv subst (arg :: args_so_far) t tl
318 let metasenv, subst, arg, ty_arg =
319 typeof ~localise metasenv subst context arg None in
320 let metasenv, meta, _ =
321 NCicMetaSubst.mk_meta metasenv
322 (("_",C.Decl ty_arg) :: context) `Type
324 let flex_prod = C.Prod ("_", ty_arg, meta) in
325 pp (lazy ( "UNIFICATION in CTX:\n"^
326 NCicPp.ppcontext ~metasenv ~subst context ^ "\nMENV:\n" ^
327 NCicPp.ppmetasenv ~subst metasenv ^ "\nOF: " ^
328 NCicPp.ppterm ~metasenv ~subst ~context t ^ " === " ^
329 NCicPp.ppterm ~metasenv ~subst ~context flex_prod ^ "\n"));
330 let metasenv, subst =
331 try NCicUnification.unify metasenv subst context t flex_prod
332 with exc -> raise (wrap_exc (lazy (localise orig_he, Printf.sprintf
333 ("The term %s is here applied to %d arguments but expects " ^^
334 "only %d arguments") (NCicPp.ppterm ~metasenv ~subst ~context he)
335 (List.length args) (List.length args_so_far))) exc)
336 (* XXX coerce to funclass *)
338 let meta = NCicSubstitution.subst ~avoid_beta_redexes:true arg meta in
339 aux metasenv subst (arg :: args_so_far) meta tl
341 aux metasenv subst [] ty_he args
342 (*D*)in outside(); rc with exc -> outside (); raise exc
344 (* vim:set foldmethod=marker: *)