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

(************************************************************************)
(*         *   The Coq Proof Assistant / The Coq Development Team       *)
(*  v      *   INRIA, CNRS and contributors - Copyright 1999-2019       *)
(* <O___,, *       (see CREDITS file for the list of authors)           *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)

(* File created by Vincent Siles, Oct 2007, extended into a generic
   support for generation of inductive schemes by Hugo Herbelin, Nov 2009 *)

(* This file provides support for registering inductive scheme builders,
   declaring schemes and generating schemes on demand *)

open Names
open Mod_subst
open Libobject
open Nameops
open Declarations
open Constr
open CErrors
open Util
open Pp

(**********************************************************************)
(* Registering schemes in the environment *)

(** flag for internal message display *)
type internal_flag =
  | UserAutomaticRequest (* kernel action, a message is displayed *)
  | InternalTacticRequest  (* kernel action, no message is displayed *)
  | UserIndividualRequest   (* user action, a message is displayed *)

type mutual_scheme_object_function =
  internal_flag -> MutInd.t -> constr array Evd.in_evar_universe_context * Evd.side_effects
type individual_scheme_object_function =
  internal_flag -> inductive -> constr Evd.in_evar_universe_context * Evd.side_effects

type 'a scheme_kind = string

let scheme_map = Summary.ref Indmap.empty ~name:"Schemes"

let pr_scheme_kind = Pp.str

let cache_one_scheme kind (ind,const) =
  let map = try Indmap.find ind !scheme_map with Not_found -> String.Map.empty in
  scheme_map := Indmap.add ind (String.Map.add kind const map) !scheme_map

let cache_scheme (_,(kind,l)) =
  Array.iter (cache_one_scheme kind) l

let subst_one_scheme subst (ind,const) =
  (* Remark: const is a def: the result of substitution is a constant *)
  (subst_ind subst ind,subst_constant subst const)

let subst_scheme (subst,(kind,l)) =
  (kind,Array.Smart.map (subst_one_scheme subst) l)

let discharge_scheme (_,(kind,l)) =
  Some (kind, l)

let inScheme : string * (inductive * Constant.t) array -> obj =
  declare_object @@ superglobal_object "SCHEME"
    ~cache:cache_scheme
    ~subst:(Some subst_scheme)
    ~discharge:discharge_scheme

(**********************************************************************)
(* The table of scheme building functions *)

type individual
type mutual

type scheme_object_function =
  | MutualSchemeFunction of mutual_scheme_object_function
  | IndividualSchemeFunction of individual_scheme_object_function

let scheme_object_table =
  (Hashtbl.create 17 : (string, string * scheme_object_function) Hashtbl.t)

let declare_scheme_object s aux f =
  let () =
    if not (Id.is_valid ("ind" ^ s)) then
      user_err Pp.(str ("Illegal induction scheme suffix: " ^ s))
  in
  let key = if String.is_empty aux then s else aux in
  try
    let _ = Hashtbl.find scheme_object_table key in
(*    let aux_msg = if aux="" then "" else " (with key "^aux^")" in*)
    user_err ~hdr:"IndTables.declare_scheme_object"
      (str "Scheme object " ++ str key ++ str " already declared.")
  with Not_found ->
    Hashtbl.add scheme_object_table key (s,f);
    key

let declare_mutual_scheme_object s ?(aux="") f =
  declare_scheme_object s aux (MutualSchemeFunction f)

let declare_individual_scheme_object s ?(aux="") f =
  declare_scheme_object s aux (IndividualSchemeFunction f)

(**********************************************************************)
(* Defining/retrieving schemes *)

let declare_scheme kind indcl =
  Lib.add_anonymous_leaf (inScheme (kind,indcl))

let () = Declare.set_declare_scheme declare_scheme

let is_visible_name id =
  try ignore (Nametab.locate (Libnames.qualid_of_ident id)); true
  with Not_found -> false

let compute_name internal id =
  match internal with
  | UserAutomaticRequest | UserIndividualRequest -> id
  | InternalTacticRequest ->
      Namegen.next_ident_away_from (add_prefix "internal_" id) is_visible_name

let define internal role id c poly univs =
  let id = compute_name internal id in
  let ctx = UState.minimize univs in
  let c = UnivSubst.nf_evars_and_universes_opt_subst (fun _ -> None) (UState.subst ctx) c in
  let univs = UState.univ_entry ~poly ctx in
  let entry = Declare.pure_definition_entry ~univs c in
  let kn, eff = Declare.declare_private_constant ~role ~kind:Decls.(IsDefinition Scheme) ~name:id entry in
  let () = match internal with
    | InternalTacticRequest -> ()
    | _-> Declare.definition_message id
  in
  kn, eff

let define_individual_scheme_base kind suff f mode idopt (mind,i as ind) =
  let (c, ctx), eff = f mode ind in
  let mib = Global.lookup_mind mind in
  let id = match idopt with
    | Some id -> id
    | None -> add_suffix mib.mind_packets.(i).mind_typename suff in
  let role = Evd.Schema (ind, kind) in
  let const, neff = define mode role id c (Declareops.inductive_is_polymorphic mib) ctx in
  declare_scheme kind [|ind,const|];
  const, Evd.concat_side_effects neff eff

let define_individual_scheme kind mode names (mind,i as ind) =
  match Hashtbl.find scheme_object_table kind with
  | _,MutualSchemeFunction f -> assert false
  | s,IndividualSchemeFunction f ->
      define_individual_scheme_base kind s f mode names ind

let define_mutual_scheme_base kind suff f mode names mind =
  let (cl, ctx), eff = f mode mind in
  let mib = Global.lookup_mind mind in
  let ids = Array.init (Array.length mib.mind_packets) (fun i ->
      try Int.List.assoc i names
      with Not_found -> add_suffix mib.mind_packets.(i).mind_typename suff) in
  let fold i effs id cl =
    let role = Evd.Schema ((mind, i), kind)in
    let cst, neff = define mode role id cl (Declareops.inductive_is_polymorphic mib) ctx in
    (Evd.concat_side_effects neff effs, cst)
  in
  let (eff, consts) = Array.fold_left2_map_i fold eff ids cl in
  let schemes = Array.mapi (fun i cst -> ((mind,i),cst)) consts in
  declare_scheme kind schemes;
  consts, eff

let define_mutual_scheme kind mode names mind =
  match Hashtbl.find scheme_object_table kind with
  | _,IndividualSchemeFunction _ -> assert false
  | s,MutualSchemeFunction f ->
      define_mutual_scheme_base kind s f mode names mind

let find_scheme_on_env_too kind ind =
  let s = String.Map.find kind (Indmap.find ind !scheme_map) in
  s, Evd.empty_side_effects

let find_scheme ?(mode=InternalTacticRequest) kind (mind,i as ind) =
  try find_scheme_on_env_too kind ind
  with Not_found ->
  match Hashtbl.find scheme_object_table kind with
  | s,IndividualSchemeFunction f ->
      define_individual_scheme_base kind s f mode None ind
  | s,MutualSchemeFunction f ->
      let ca, eff = define_mutual_scheme_base kind s f mode [] mind in
      ca.(i), eff

let check_scheme kind ind =
  try let _ = find_scheme_on_env_too kind ind in true
  with Not_found -> false