File refute_isar.ML

(*  Title:      HOL/Tools/refute_isar.ML
    ID:         $Id$
    Author:     Tjark Weber
    Copyright   2003-2007

Adds the 'refute' and 'refute_params' commands to Isabelle/Isar's outer
syntax.
*)

structure RefuteIsar: sig end =
struct

(* ------------------------------------------------------------------------- *)
(* common functions for argument parsing/scanning                            *)
(* ------------------------------------------------------------------------- *)

(* ------------------------------------------------------------------------- *)
(* both 'refute' and 'refute_params' take an optional list of arguments of   *)
(* the form [name1=value1, name2=value2, ...]                                *)
(* ------------------------------------------------------------------------- *)

	val scan_parm = OuterParse.name -- (OuterParse.$$$ "=" |-- OuterParse.name);

	val scan_parms = Scan.option
		(OuterParse.$$$ "[" |-- (OuterParse.list scan_parm) --| OuterParse.$$$ "]");

(* ------------------------------------------------------------------------- *)
(* set up the 'refute' command                                               *)
(* ------------------------------------------------------------------------- *)

(* ------------------------------------------------------------------------- *)
(* 'refute' takes an optional list of parameters, followed by an optional    *)
(* subgoal number                                                            *)
(* ------------------------------------------------------------------------- *)

	val refute_scan_args = scan_parms -- (Scan.option OuterParse.nat);

(* ------------------------------------------------------------------------- *)
(* the 'refute' command is mapped to 'Refute.refute_subgoal'                 *)
(* ------------------------------------------------------------------------- *)

	fun refute_trans args =
		Toplevel.keep (fn state =>
			let
				val (parms_opt, subgoal_opt) = args
				val parms   = Option.getOpt (parms_opt, [])
				val subgoal = Option.getOpt (subgoal_opt, 1) - 1
				val thy     = Toplevel.theory_of state
				val thm     = (snd o snd) (Proof.get_goal (Toplevel.proof_of state))
			in
				Refute.refute_subgoal thy parms thm subgoal
			end);

	fun refute_parser tokens = (refute_scan_args tokens) |>> refute_trans;

	val _ = OuterSyntax.improper_command "refute"
		"try to find a model that refutes a given subgoal"
		OuterKeyword.diag refute_parser;

(* ------------------------------------------------------------------------- *)
(* set up the 'refute_params' command                                        *)
(* ------------------------------------------------------------------------- *)

(* ------------------------------------------------------------------------- *)
(* 'refute_params' takes an optional list of parameters                      *)
(* ------------------------------------------------------------------------- *)

	val refute_params_scan_args = scan_parms;

(* ------------------------------------------------------------------------- *)
(* the 'refute_params' command is mapped to (multiple calls of)              *)
(* 'Refute.set_default_param'; then the (new) default parameters are         *)
(* displayed                                                                 *)
(* ------------------------------------------------------------------------- *)

	fun refute_params_trans args =
		let
			fun add_params thy [] =
				thy
			  | add_params thy (p::ps) =
				add_params (Refute.set_default_param p thy) ps
		in
			Toplevel.theory (fn thy =>
				let
					val thy'               = add_params thy (getOpt (args, []))
					val new_default_params = Refute.get_default_params thy'
					val output             = if new_default_params=[] then
							"none"
						else
							cat_lines (map (fn (name, value) => name ^ "=" ^ value)
								new_default_params)
				in
					writeln ("Default parameters for 'refute':\n" ^ output);
					thy'
				end)
		end;

	fun refute_params_parser tokens =
		(refute_params_scan_args tokens) |>> refute_params_trans;

	val _ = OuterSyntax.command "refute_params"
		"show/store default parameters for the 'refute' command"
		OuterKeyword.thy_decl refute_params_parser;

end;