summaryrefslogtreecommitdiff
path: root/contrib/subtac/subtac_classes.ml
blob: 15addb44ae007cad396c1d19322ff9a1ab9c95fa (plain)
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
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, * CNRS-Ecole Polytechnique-INRIA Futurs-Universite Paris Sud *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

(*i $Id: subtac_classes.ml 11047 2008-06-03 23:08:00Z msozeau $ i*)

open Pretyping
open Evd
open Environ
open Term
open Rawterm
open Topconstr
open Names
open Libnames
open Pp
open Vernacexpr
open Constrintern
open Subtac_command
open Typeclasses
open Typeclasses_errors
open Termops
open Decl_kinds
open Entries
open Util

module SPretyping = Subtac_pretyping.Pretyping

let interp_binder_evars evdref env na t =
  let t = Constrintern.intern_gen true (Evd.evars_of !evdref) env t in
    SPretyping.understand_tcc_evars evdref env IsType t

let interp_binders_evars isevars env avoid l =
  List.fold_left
    (fun (env, ids, params) ((loc, i), t) -> 
      let n = Name i in
      let t' = interp_binder_evars isevars env n t in
      let d = (i,None,t') in
	(push_named d env, i :: ids, d::params))
    (env, avoid, []) l

let interp_typeclass_context_evars isevars env avoid l =
  List.fold_left
    (fun (env, ids, params) (iid, bk, cl) -> 
      let t' = interp_binder_evars isevars env (snd iid) cl in
      let i = match snd iid with
	| Anonymous -> Nameops.next_name_away (Termops.named_hd env t' Anonymous) ids
	| Name id -> id
      in
      let d = (i,None,t') in
	(push_named d env, i :: ids, d::params))
    (env, avoid, []) l

let interp_constrs_evars isevars env avoid l =
  List.fold_left
    (fun (env, ids, params) t -> 
      let t' = interp_binder_evars isevars env Anonymous t in
      let id = Nameops.next_name_away (Termops.named_hd env t' Anonymous) ids in
      let d = (id,None,t') in
	(push_named d env, id :: ids, d::params))
    (env, avoid, []) l
    
let interp_constr_evars_gen evdref env ?(impls=([],[])) kind c =
  SPretyping.understand_tcc_evars evdref env kind
    (intern_gen (kind=IsType) ~impls (Evd.evars_of !evdref) env c)

let interp_casted_constr_evars evdref env ?(impls=([],[])) c typ =
  interp_constr_evars_gen evdref env ~impls (OfType (Some typ)) c

let type_ctx_instance isevars env ctx inst subst =
  List.fold_left2
    (fun (subst, instctx) (na, _, t) ce ->
      let t' = replace_vars subst t in
      let c = interp_casted_constr_evars isevars env ce t' in
      let d = na, Some c, t' in
	(na, c) :: subst, d :: instctx)
    (subst, []) (List.rev ctx) inst

(*let superclass_ce = CRef (Ident (dummy_loc, id_of_string ".superclass"))*)

let type_class_instance_params isevars env id n ctx inst subst =
  List.fold_left2
    (fun (subst, instctx) (na, _, t) ce ->
      let t' = replace_vars subst t in
      let c = 
(* 	if ce = superclass_ce then *)
	(* 	  (\* Control over the evars which are direct superclasses to avoid partial instanciations *)
	(* 	     in instance search. *\) *)
	(* 	  Evarutil.e_new_evar isevars env ~src:(dummy_loc, ImplicitArg (VarRef id, (n, Some na))) t' *)
	(* 	else *)
	interp_casted_constr_evars isevars env ce t' 
      in
      let d = na, Some c, t' in
	(na, c) :: subst, d :: instctx)
    (subst, []) (List.rev ctx) inst

let substitution_of_constrs ctx cstrs =
  List.fold_right2 (fun c (na, _, _) acc -> (na, c) :: acc) cstrs ctx []

let new_instance ?(global=false) ctx (instid, bk, cl) props ?(on_free_vars=Classes.default_on_free_vars) pri =
  let env = Global.env() in
  let isevars = ref (Evd.create_evar_defs Evd.empty) in
  let bound = Implicit_quantifiers.ids_of_list (Termops.ids_of_context env) in
  let bound, fvs = Implicit_quantifiers.free_vars_of_binders ~bound [] ctx in
  let tclass =
    match bk with
      | Implicit ->
	  let loc, id, par = Implicit_quantifiers.destClassAppExpl cl in
	  let k = class_info (Nametab.global id) in
	  let applen = List.fold_left (fun acc (x, y) -> if y = None then succ acc else acc) 0 par in
	  let needlen = List.fold_left (fun acc (x, y) -> if x = None then succ acc else acc) 0 k.cl_context in
	    if needlen <> applen then 
	      Classes.mismatched_params env (List.map fst par) (List.map snd k.cl_context);
	    let pars, _ = Implicit_quantifiers.combine_params Idset.empty (* need no avoid *)
	      (fun avoid (clname, (id, _, t)) -> 
		match clname with 
		    Some (cl, b) -> 
		      let t = 
			if b then 
			  let _k = class_info cl in
			    CHole (Util.dummy_loc, Some Evd.InternalHole) (* (Evd.ImplicitArg (IndRef k.cl_impl, (1, None)))) *)
			else CHole (Util.dummy_loc, None)
		      in t, avoid
		  | None -> failwith ("new instance: under-applied typeclass"))
	      par (List.rev k.cl_context)
	    in Topconstr.CAppExpl (loc, (None, id), pars)

      | Explicit -> cl
  in
  let ctx_bound = Idset.union bound (Implicit_quantifiers.ids_of_list fvs) in
  let gen_ids = Implicit_quantifiers.free_vars_of_constr_expr ~bound:ctx_bound tclass [] in
  let bound = Idset.union (Implicit_quantifiers.ids_of_list gen_ids) ctx_bound in
  on_free_vars (List.rev (gen_ids @ fvs));
  let gen_ctx = Implicit_quantifiers.binder_list_of_ids gen_ids in
  let ctx, avoid = Classes.name_typeclass_binders bound ctx in
  let ctx = List.append ctx (List.rev gen_ctx) in
  let k, ctx', imps, subst = 
    let c = Command.generalize_constr_expr tclass ctx in
    let c', imps = interp_type_evars_impls ~evdref:isevars env c in
    let ctx, c = Classes.decompose_named_assum c' in
    let cl, args = Typeclasses.dest_class_app c in
      cl, ctx, imps, substitution_of_constrs (List.map snd cl.cl_context) (List.rev (Array.to_list args))
  in
  let id = 
    match snd instid with
	Name id -> 
	  let sp = Lib.make_path id in
	    if Nametab.exists_cci sp then
	      errorlabstrm "new_instance" (Nameops.pr_id id ++ Pp.str " already exists");
	    id
      | Anonymous -> 
	  let i = Nameops.add_suffix (Classes.id_of_class k) "_instance_0" in
	    Termops.next_global_ident_away false i (Termops.ids_of_context env)
  in
  let env' = Classes.push_named_context ctx' env in
  isevars := Evarutil.nf_evar_defs !isevars;
  isevars := resolve_typeclasses ~onlyargs:false ~fail:true env' !isevars;
  let sigma = Evd.evars_of !isevars in
  let substctx = Typeclasses.nf_substitution sigma subst in
  let subst, _propsctx = 
    let props = 
      List.map (fun (x, l, d) -> 
	x, Topconstr.abstract_constr_expr d (Classes.binders_of_lidents l))
	props
    in
      if List.length props > List.length k.cl_props then 
	Classes.mismatched_props env' (List.map snd props) k.cl_props;
      let props, rest = 
	List.fold_left
	  (fun (props, rest) (id,_,_) -> 
	    try 
	      let ((loc, mid), c) = List.find (fun ((_,id'), c) -> id' = id) rest in
	      let rest' = List.filter (fun ((_,id'), c) -> id' <> id) rest in
		Constrintern.add_glob loc (ConstRef (List.assoc mid k.cl_projs));
		c :: props, rest'
	    with Not_found -> (CHole (Util.dummy_loc, None) :: props), rest)
	  ([], props) k.cl_props
      in
	if rest <> [] then 
	  unbound_method env' k.cl_impl (fst (List.hd rest))
	else
	  type_ctx_instance isevars env' k.cl_props props substctx
  in
  let inst_constr, ty_constr = instance_constructor k (List.rev_map snd subst) in
    isevars := Evarutil.nf_evar_defs !isevars;
    let term = Evarutil.nf_isevar !isevars (it_mkNamedLambda_or_LetIn inst_constr ctx')
    and termtype = Evarutil.nf_isevar !isevars (it_mkNamedProd_or_LetIn ty_constr ctx') 
    in
      isevars := undefined_evars !isevars;
      Evarutil.check_evars env Evd.empty !isevars termtype;
(*   let imps =  *)
(*     Util.list_map_i  *)
(*       (fun i binder -> *)
(* 	match binder with *)
(* 	ExplByPos (i, Some na), (true, true)) *)
(*       1 ctx *)
(*   in *)
      let hook gr = 
	let cst = match gr with ConstRef kn -> kn | _ -> assert false in
	let inst = Typeclasses.new_instance k pri global cst in
	  Impargs.declare_manual_implicits false gr false imps;
	  Typeclasses.add_instance inst
      in
      let evm = Subtac_utils.evars_of_term (Evd.evars_of !isevars) Evd.empty term in
      let obls, constr, typ = Eterm.eterm_obligations env id !isevars evm 0 term termtype in
	ignore(Subtac_obligations.add_definition id constr typ ~kind:(Global,false,Instance) ~hook obls);
	id