aboutsummaryrefslogtreecommitdiffhomepage
path: root/plugins/ltac/taccoerce.ml
blob: 117a16b0af04d73a4447e5d279dd6be5db5f9ff5 (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
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
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
(************************************************************************)
(*  v      *   The Coq Proof Assistant  /  The Coq Development Team     *)
(* <O___,, *   INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2016     *)
(*   \VV/  **************************************************************)
(*    //   *      This file is distributed under the terms of the       *)
(*         *       GNU Lesser General Public License Version 2.1        *)
(************************************************************************)

open API
open Util
open Names
open Term
open EConstr
open Pattern
open Misctypes
open Genarg
open Stdarg
open Geninterp

exception CannotCoerceTo of string

let (wit_constr_context : (Empty.t, Empty.t, EConstr.constr) Genarg.genarg_type) =
  let wit = Genarg.create_arg "constr_context" in
  let () = register_val0 wit None in
  wit

(* includes idents known to be bound and references *)
let (wit_constr_under_binders : (Empty.t, Empty.t, constr_under_binders) Genarg.genarg_type) =
  let wit = Genarg.create_arg "constr_under_binders" in
  let () = register_val0 wit None in
  wit

(** All the types considered here are base types *)
let val_tag wit = match val_tag wit with
| Val.Base t -> t
| _ -> assert false

let has_type : type a. Val.t -> a typed_abstract_argument_type -> bool = fun v wit ->
  let Val.Dyn (t, _) = v in
  match Val.eq t (val_tag wit) with
  | None -> false
  | Some Refl -> true

let prj : type a. a Val.typ -> Val.t -> a option = fun t v ->
  let Val.Dyn (t', x) = v in
  match Val.eq t t' with
  | None -> None
  | Some Refl -> Some x

let in_gen wit v = Val.Dyn (val_tag wit, v)
let out_gen wit v = match prj (val_tag wit) v with None -> assert false | Some x -> x

module Value =
struct

type t = Val.t

let normalize v = v

let of_constr c = in_gen (topwit wit_constr) c

let to_constr v =
  let v = normalize v in
  if has_type v (topwit wit_constr) then
    let c = out_gen (topwit wit_constr) v in
    Some c
  else if has_type v (topwit wit_constr_under_binders) then
    let vars, c = out_gen (topwit wit_constr_under_binders) v in
    match vars with [] -> Some c | _ -> None
  else None

let of_uconstr c = in_gen (topwit wit_uconstr) c

let to_uconstr v =
  let v = normalize v in
  if has_type v (topwit wit_uconstr) then
    Some (out_gen (topwit wit_uconstr) v)
  else None

let of_int i = in_gen (topwit wit_int) i

let to_int v =
  let v = normalize v in
  if has_type v (topwit wit_int) then
    Some (out_gen (topwit wit_int) v)
  else None

let to_list v = prj Val.typ_list v

let to_option v = prj Val.typ_opt v

let to_pair v = prj Val.typ_pair v

end

let is_variable env id =
  Id.List.mem id (Termops.ids_of_named_context (Environ.named_context env))

(* Transforms an id into a constr if possible, or fails with Not_found *)
let constr_of_id env id =
  EConstr.mkVar (let _ = Environ.lookup_named id env in id)

(* Gives the constr corresponding to a Constr_context tactic_arg *)
let coerce_to_constr_context v =
  let v = Value.normalize v in
  if has_type v (topwit wit_constr_context) then
    out_gen (topwit wit_constr_context) v
  else raise (CannotCoerceTo "a term context")

(* Interprets an identifier which must be fresh *)
let coerce_var_to_ident fresh env sigma v =
  let v = Value.normalize v in
  let fail () = raise (CannotCoerceTo "a fresh identifier") in
  if has_type v (topwit wit_intro_pattern) then
    match out_gen (topwit wit_intro_pattern) v with
    | _, IntroNaming (IntroIdentifier id) -> id
    | _ -> fail ()
  else if has_type v (topwit wit_var) then
    out_gen (topwit wit_var) v
  else match Value.to_constr v with
  | None -> fail ()
  | Some c ->
    (* We need it fresh for intro e.g. in "Tac H = clear H; intro H" *)
    if isVar sigma c && not (fresh && is_variable env (destVar sigma c)) then
      destVar sigma c
    else fail ()


(* Interprets, if possible, a constr to an identifier which may not
   be fresh but suitable to be given to the fresh tactic. Works for
   vars, constants, inductive, constructors and sorts. *)
let coerce_to_ident_not_fresh env sigma v =
let g = sigma in
let id_of_name = function
  | Name.Anonymous -> Id.of_string "x"
  | Name.Name x -> x in
  let v = Value.normalize v in
  let fail () = raise (CannotCoerceTo "an identifier") in
  if has_type v (topwit wit_intro_pattern) then
    match out_gen (topwit wit_intro_pattern) v with
    | _, IntroNaming (IntroIdentifier id) -> id
    | _ -> fail ()
  else if has_type v (topwit wit_var) then
    out_gen (topwit wit_var) v
  else
    match Value.to_constr v with
    | None -> fail ()
    | Some c ->
       match EConstr.kind sigma c with
       | Var id -> id 
       | Meta m -> id_of_name (Evd.meta_name g m)
       | Evar (kn,_) ->
        begin match Evd.evar_ident kn g with
        | None -> fail ()
        | Some id -> id
        end
       | Const (cst,_) -> Label.to_id (Constant.label cst)
       | Construct (cstr,_) ->
	  let ref = Globnames.ConstructRef cstr in
	  let basename = Nametab.basename_of_global ref in
	  basename
       | Ind (ind,_) ->
	  let ref = Globnames.IndRef ind in
	  let basename = Nametab.basename_of_global ref in
	  basename
       | Sort s ->
	  begin
	    match ESorts.kind sigma s with
	    | Prop _ -> Label.to_id (Label.make "Prop")
	    | Type _ -> Label.to_id (Label.make "Type")
	  end
       | _ -> fail()


let coerce_to_intro_pattern env sigma v =
  let v = Value.normalize v in
  if has_type v (topwit wit_intro_pattern) then
    snd (out_gen (topwit wit_intro_pattern) v)
  else if has_type v (topwit wit_var) then
    let id = out_gen (topwit wit_var) v in
    IntroNaming (IntroIdentifier id)
  else match Value.to_constr v with
  | Some c when isVar sigma c ->
      (* This happens e.g. in definitions like "Tac H = clear H; intro H" *)
      (* but also in "destruct H as (H,H')" *)
      IntroNaming (IntroIdentifier (destVar sigma c))
  | _ -> raise (CannotCoerceTo "an introduction pattern")

let coerce_to_intro_pattern_naming env sigma v =
  match coerce_to_intro_pattern env sigma v with
  | IntroNaming pat -> pat
  | _ -> raise (CannotCoerceTo "a naming introduction pattern")

let coerce_to_hint_base v =
  let v = Value.normalize v in
  if has_type v (topwit wit_intro_pattern) then
    match out_gen (topwit wit_intro_pattern) v with
    | _, IntroNaming (IntroIdentifier id) -> Id.to_string id
    | _ -> raise (CannotCoerceTo "a hint base name")
  else raise (CannotCoerceTo "a hint base name")

let coerce_to_int v =
  let v = Value.normalize v in
  if has_type v (topwit wit_int) then
    out_gen (topwit wit_int) v
  else raise (CannotCoerceTo "an integer")

let coerce_to_constr env v =
  let v = Value.normalize v in
  let fail () = raise (CannotCoerceTo "a term") in
  if has_type v (topwit wit_intro_pattern) then
    match out_gen (topwit wit_intro_pattern) v with
    | _, IntroNaming (IntroIdentifier id) ->
      (try ([], constr_of_id env id) with Not_found -> fail ())
    | _ -> fail ()
  else if has_type v (topwit wit_constr) then
    let c = out_gen (topwit wit_constr) v in
    ([], c)
  else if has_type v (topwit wit_constr_under_binders) then
    out_gen (topwit wit_constr_under_binders) v
  else if has_type v (topwit wit_var) then
    let id = out_gen (topwit wit_var) v in
    (try [], constr_of_id env id with Not_found -> fail ())
  else fail ()

let coerce_to_uconstr env v =
  let v = Value.normalize v in
  if has_type v (topwit wit_uconstr) then
    out_gen (topwit wit_uconstr) v
  else
    raise (CannotCoerceTo "an untyped term")

let coerce_to_closed_constr env v =
  let ids,c = coerce_to_constr env v in
  let () = if not (List.is_empty ids) then raise (CannotCoerceTo "a term") in
  c

let coerce_to_evaluable_ref env sigma v =
  let fail () = raise (CannotCoerceTo "an evaluable reference") in
  let v = Value.normalize v in
  let ev =
  if has_type v (topwit wit_intro_pattern) then
    match out_gen (topwit wit_intro_pattern) v with
    | _, IntroNaming (IntroIdentifier id) when is_variable env id -> EvalVarRef id
    | _ -> fail ()
  else if has_type v (topwit wit_var) then
    let id = out_gen (topwit wit_var) v in
    if Id.List.mem id (Termops.ids_of_context env) then EvalVarRef id
    else fail ()
  else if has_type v (topwit wit_ref) then
    let open Globnames in
    let r = out_gen (topwit wit_ref) v in
    match r with
    | VarRef var -> EvalVarRef var
    | ConstRef c -> EvalConstRef c
    | IndRef _ | ConstructRef _ -> fail ()
  else
    match Value.to_constr v with
    | Some c when isConst sigma c -> EvalConstRef (fst (destConst sigma c))
    | Some c when isVar sigma c -> EvalVarRef (destVar sigma c)
    | _ -> fail ()
  in if Tacred.is_evaluable env ev then ev else fail ()

let coerce_to_constr_list env v =
  let v = Value.to_list v in
  match v with
  | Some l ->
    let map v = coerce_to_closed_constr env v in
    List.map map l
  | None -> raise (CannotCoerceTo "a term list")

let coerce_to_intro_pattern_list ?loc env sigma v =
  match Value.to_list v with
  | None -> raise (CannotCoerceTo "an intro pattern list")
  | Some l ->
    let map v = Loc.tag ?loc @@ coerce_to_intro_pattern env sigma v in
    List.map map l

let coerce_to_hyp env sigma v =
  let fail () = raise (CannotCoerceTo "a variable") in
  let v = Value.normalize v in
  if has_type v (topwit wit_intro_pattern) then
    match out_gen (topwit wit_intro_pattern) v with
    | _, IntroNaming (IntroIdentifier id) when is_variable env id -> id
    | _ -> fail ()
  else if has_type v (topwit wit_var) then
    let id = out_gen (topwit wit_var) v in
    if is_variable env id then id else fail ()
  else match Value.to_constr v with
  | Some c when isVar sigma c -> destVar sigma c
  | _ -> fail ()

let coerce_to_hyp_list env sigma v =
  let v = Value.to_list v in
  match v with
  | Some l ->
    let map n = coerce_to_hyp env sigma n in
    List.map map l
  | None -> raise (CannotCoerceTo "a variable list")

(* Interprets a qualified name *)
let coerce_to_reference env sigma v =
  let v = Value.normalize v in
  match Value.to_constr v with
  | Some c ->
    begin
      try fst (Termops.global_of_constr sigma c)
      with Not_found -> raise (CannotCoerceTo "a reference")
    end
  | None -> raise (CannotCoerceTo "a reference")

(* Quantified named or numbered hypothesis or hypothesis in context *)
(* (as in Inversion) *)
let coerce_to_quantified_hypothesis sigma v =
  let v = Value.normalize v in
  if has_type v (topwit wit_intro_pattern) then
    let v = out_gen (topwit wit_intro_pattern) v in
    match v with
    | _, IntroNaming (IntroIdentifier id) -> NamedHyp id
    | _ -> raise (CannotCoerceTo "a quantified hypothesis")
  else if has_type v (topwit wit_var) then
    let id = out_gen (topwit wit_var) v in
    NamedHyp id
  else if has_type v (topwit wit_int) then
    AnonHyp (out_gen (topwit wit_int) v)
  else match Value.to_constr v with
  | Some c when isVar sigma c -> NamedHyp (destVar sigma c)
  | _ -> raise (CannotCoerceTo "a quantified hypothesis")

(* Quantified named or numbered hypothesis or hypothesis in context *)
(* (as in Inversion) *)
let coerce_to_decl_or_quant_hyp env sigma v =
  let v = Value.normalize v in
  if has_type v (topwit wit_int) then
    AnonHyp (out_gen (topwit wit_int) v)
  else
    try coerce_to_quantified_hypothesis sigma v
    with CannotCoerceTo _ ->
      raise (CannotCoerceTo "a declared or quantified hypothesis")

let coerce_to_int_or_var_list v =
  match Value.to_list v with
  | None -> raise (CannotCoerceTo "an int list")
  | Some l ->
    let map n = ArgArg (coerce_to_int n) in
    List.map map l