Source file `Strategy.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
(**************************************************************************)
(*                                                                        *)
(*  This file is part of WP plug-in of Frama-C.                           *)
(*                                                                        *)
(*  Copyright (C) 2007-2023                                               *)
(*    CEA (Commissariat a l'energie atomique et aux energies              *)
(*         alternatives)                                                  *)
(*                                                                        *)
(*  you can redistribute it and/or modify it under the terms of the GNU   *)
(*  Lesser General Public License as published by the Free Software       *)
(*  Foundation, version 2.1.                                              *)
(*                                                                        *)
(*  It is distributed in the hope that it will be useful,                 *)
(*  but WITHOUT ANY WARRANTY; without even the implied warranty of        *)
(*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *)
(*  GNU Lesser General Public License for more details.                   *)
(*                                                                        *)
(*  See the GNU Lesser General Public License version 2.1                 *)
(*  for more details (enclosed in the file licenses/LGPLv2.1).            *)
(*                                                                        *)
(**************************************************************************)

(* -------------------------------------------------------------------------- *)
(* --- Lookup Selection                                                   --- *)
(* -------------------------------------------------------------------------- *)

open Lang
open Lang.F
open Tactical
open Conditions

type lookup = {
  target : Lang.F.term ;
  mutable marked : Tset.t ;
}

let lookup_term env e =
  let rec walk env e =
    if e == env.target then raise Exit ;
    if not (Tset.mem e env.marked) then
      begin
        env.marked <- Tset.add e env.marked ;
        Lang.F.lc_iter (walk env) e ;
      end
  in
  try walk env e ; false
  with Exit -> true

let occurs_x x a = F.Vars.mem x (F.vars a)
let occurs_y x p = F.Vars.mem x (F.varsp p)
let occurs_e a b = lookup_term { target = a ; marked = Tset.empty } b
let occurs_p a p = occurs_e a (F.e_prop p)
let occurs_q p q = occurs_e (F.e_prop p) (F.e_prop q)

let lookup_step env queue s =
  match s.condition with
  | State _ -> Empty
  | When p | Have p | Init p | Core p | Type p ->
    let p = Lang.F.e_prop p in
    if p == env.target then Clause(Step s) else
    if lookup_term env p then Inside(Step s,env.target) else Empty
  | Branch(c,sa,sb) ->
    let p = Lang.F.e_prop c in
    if lookup_term env p then Inside(Step s,env.target) else
      ( Queue.add sa queue ; Queue.add sb queue ; Empty )
  | Either cs ->
    List.iter (fun s -> Queue.add s queue) cs ; Empty

exception Found of selection

let lookup_sequence env queue seq =
  Conditions.iter
    (fun s ->
       match lookup_step env queue s with
       | Empty -> ()
       | sel -> raise (Found sel)
    ) seq

let select_e (sequence,goal) e =
  let g = Lang.F.e_prop goal in
  if g == e then Clause(Goal goal) else
    let env = { target = e ; marked = Tset.empty } in
    if lookup_term env g then Inside(Goal goal,e) else
      try
        let queue = Queue.create () in
        lookup_sequence env queue sequence ;
        while not (Queue.is_empty queue) do
          lookup_sequence env queue (Queue.pop queue)
        done ; Empty
      with Found sel -> sel

let select_p seq p = select_e seq (F.e_prop p)

(* -------------------------------------------------------------------------- *)
(* --- Elementary Tactics                                                 --- *)
(* -------------------------------------------------------------------------- *)

type argument = ARG: 'a field * 'a -> argument

type strategy = {
  priority : float ;
  tactical : tactical ;
  selection : selection ;
  arguments : argument list ;
} and t = strategy

let highest a b = Stdlib.compare b.priority a.priority

class pool =
  object
    val pool : strategy Vector.t = Vector.create ()
    method add = Vector.add pool
    method sort =
      let hs = Vector.to_array pool in
      Array.stable_sort highest hs ; hs
  end

class type heuristic =
  object
    method id : string
    method title : string
    method descr : string
    method search : (strategy -> unit) -> sequent -> unit
  end

module Tmap = Map.Make(String)
let registry = ref Tmap.empty

let register s =
  let id = s#id in
  if Tmap.mem id !registry then
    Wp_parameters.error "Strategy #%s already registered (skipped)" id
  else
    registry := Tmap.add id (s :> heuristic) !registry

let export s = register s ; (s :> heuristic)

let lookup ~id = Tmap.find id !registry

let iter f = Tmap.iter (fun _ s -> f s) !registry

let arg fd v = ARG(fd,v)
let set_arg (tactical : #tactical) =
  function ARG(fd,v) -> tactical#set_field fd v
let set_args tactical arguments =
  List.iter (set_arg tactical) arguments

let make tactical ?(priority=1.0) ?(arguments=[]) selection =
  { priority ; tactical ; selection ; arguments }

(* -------------------------------------------------------------------------- *)