src/Pure/Isar/skip_proof.ML

added future_scheduler (from thy_info.ML);
prove: Goal.prove_promise if future_schedule;

(*  Title:      Pure/Isar/skip_proof.ML
    ID:         $Id$
    Author:     Markus Wenzel, TU Muenchen

Skipping proofs -- quick_and_dirty mode.
*)

val future_scheduler = ref false;

signature SKIP_PROOF =
sig
  val make_thm: theory -> term -> thm
  val cheat_tac: theory -> tactic
  val prove: Proof.context -> string list -> term list -> term ->
    ({prems: thm list, context: Proof.context} -> tactic) -> thm
  val prove_global: theory -> string list -> term list -> term ->
    ({prems: thm list, context: Proof.context} -> tactic) -> thm
end;

structure SkipProof: SKIP_PROOF =
struct

(* oracle setup *)

val (_, skip_proof) = Context.>>> (Context.map_theory_result
  (Thm.add_oracle ("skip_proof", fn (thy, prop) =>
    if ! quick_and_dirty then Thm.cterm_of thy prop
    else error "Proof may be skipped in quick_and_dirty mode only!")));


(* basic cheating *)

fun make_thm thy prop = skip_proof (thy, prop);

fun cheat_tac thy st =
  ALLGOALS (Tactic.rtac (make_thm thy (Var (("A", 0), propT)))) st;

fun prove ctxt xs asms prop tac =
  (if ! future_scheduler then Goal.prove_promise else Goal.prove) ctxt xs asms prop
    (fn args => fn st =>
      if ! quick_and_dirty
      then setmp quick_and_dirty true (cheat_tac (ProofContext.theory_of ctxt)) st
      else tac args st);

fun prove_global thy xs asms prop tac =
  Drule.standard (prove (ProofContext.init thy) xs asms prop tac);

end;