(* Title: Pure/par_tactical.ML
Author: Makarius
Parallel tacticals.
*)
signature BASIC_PAR_TACTICAL =
sig
val PARALLEL_CHOICE: tactic list -> tactic
val PARALLEL_GOALS: tactic -> tactic
val PARALLEL_ALLGOALS: (int -> tactic) -> tactic
end;
signature PAR_TACTICAL =
sig
include BASIC_PAR_TACTICAL
end;
structure Par_Tactical: PAR_TACTICAL =
struct
(* parallel choice of single results *)
fun PARALLEL_CHOICE tacs st =
(case Par_List.get_some (fn tac => SINGLE tac st) tacs of
NONE => Seq.empty
| SOME st' => Seq.single st');
(* parallel refinement of non-schematic goal by single results *)
local
exception FAILED of unit;
fun retrofit st' =
rotate_prems ~1 #>
Thm.bicompose NONE {flatten = false, match = false, incremented = false}
(false, Goal.conclude st', Thm.nprems_of st') 1;
in
fun PARALLEL_GOALS tac st =
if not (Multithreading.enabled ()) orelse Thm.nprems_of st <= 1 then DETERM tac st
else
let val subgoals = map (Thm.adjust_maxidx_cterm ~1) (Drule.strip_imp_prems (Thm.cprop_of st)) in
if exists (fn sg => Thm.maxidx_of_cterm sg >= 0) subgoals then DETERM tac st
else
let
fun try_tac g =
(case SINGLE tac g of
NONE => raise FAILED ()
| SOME g' => g');
val results = Par_List.map (try_tac o Goal.init) subgoals;
in EVERY (map retrofit (rev results)) st end
handle FAILED () => Seq.empty
end;
end;
val PARALLEL_ALLGOALS = PARALLEL_GOALS o ALLGOALS;
end;
structure Basic_Par_Tactical: BASIC_PAR_TACTICAL = Par_Tactical;
open Basic_Par_Tactical;