(* Handle user-input during the specify- and the solve-phase. 

    author: Walther Neuper

    0603

    (c) due to copyright terms

 In case a term is input, which contains an "error pattern" (provided by a mathauthor),

 several "fill patterns" can be presented as help for the next step.)

 *)

 signature ERROR_FILL_PATTERN =

 sig

   type errpatID = Rule_Def.errpatID

   type errpat = errpatID * term list * thm list

   val errpats2str : errpat list -> string

   val find_fillpatterns : Calc.T -> Error_Fill_Def.errpatID ->

     (Error_Fill_Def.fillpatID * term * thm * Selem.subs option) list

   val fetchErrorpatterns : Tactic.input -> Error_Fill_Def.errpatID list

   val is_exactly_equal : Calc.T -> string -> string * Tactic.input

   val check_for : term * term -> term * (term * term) list ->

     (Error_Fill_Def.errpatID * term list * 'a list) list * Rule_Set.T ->

       Error_Fill_Def.errpatID option

 (* ---- for tests only: shifted from below to remove the Warning "unused" at fun.def. --------- *)

   (*  NONE *)

 (*/-------------------------------------------------------- ! aktivate for Test_Isac BEGIN ---\* )

   val check_err_patt : term * term -> UnparseC.subst -> Error_Fill_Def.errpatID * term -> Rule_Set.T -> Error_Fill_Def.errpatID option

   val get_fillform :

      'a * (term * term) list -> 'b * term -> Error_Fill_Def.errpatID -> Error_Fill_Def.fillpat -> (Error_Fill_Def.fillpatID * term * 'b * 'a) option

   val get_fillpats :

      'a * (term * term) list -> term -> Error_Fill_Def.errpatID -> thm -> (Error_Fill_Def.fillpatID * term * thm * 'a) list

 ( *\--- ! aktivate for Test_Isac END ----------------------------------------------------------/*)

 end

 (**)

 structure Error_Fill_Pattern(**): ERROR_FILL_PATTERN(**) =

 struct

 (**)

 type errpatID = Rule_Def.errpatID

 (* check if (agreed result, input formula) matches the error pattern "pat" modulo simplifier rls *)

 fun check_err_patt (res, inf) subst (errpatID, pat) rls =

   let 

     val (res', _, _, rewritten) =

       Rewrite.rew_sub (ThyC.Isac()) 1 subst Rewrite_Ord.e_rew_ord Rule_Set.empty false [] (HOLogic.Trueprop $ pat) res;

   in

     if rewritten then 

       let

         val norm_res = case Rewrite.rewrite_set_inst_ (ThyC.Isac()) false subst rls  res' of

           NONE => res'

         | SOME (norm_res, _) => norm_res

         val norm_inf = case Rewrite.rewrite_set_inst_ (ThyC.Isac()) false subst rls inf of

           NONE => inf

         | SOME (norm_inf, _) => norm_inf

       in if norm_res = norm_inf then SOME errpatID else NONE

       end

     else NONE

   end;

 (*

   check if (agreed result, input formula) matches SOME error pattern modulo simplifier rls;

   (prog, env) for retrieval of casual substitution for bdv in the pattern.

 *)

 fun check_for (res, inf) (prog, env) (errpats, rls) =

   let

     val (_, subst) = Rtools.get_bdv_subst prog env

     fun scan (_, [], _) = NONE

       | scan (errpatID, errpat :: errpats, _) =

           case check_err_patt (res, inf) subst (errpatID, errpat) rls of

             NONE => scan (errpatID, errpats, [])

           | SOME errpatID => SOME errpatID

     fun scans [] = NONE

       | scans (group :: groups) =

           case scan group of

             NONE => scans groups

           | SOME errpatID => SOME errpatID

   in scans errpats end;

 (* fill-in patterns an forms.

   returns thm required by "fun in_fillform *)

 fun get_fillform (subs_opt, subst) (thm, form) errpatID (fillpatID, pat, erpaID) =

   let

     val (form', _, _, rewritten) =

       Rewrite.rew_sub (ThyC.Isac()) 1 subst Rewrite_Ord.e_rew_ord Rule_Set.empty false [] (HOLogic.Trueprop $ pat) form;

   in (*the fillpat of the thm must be dedicated to errpatID*)

     if errpatID = erpaID andalso rewritten then

       SOME (fillpatID, HOLogic.mk_eq (form, form'), thm, subs_opt) 

     else NONE

   end

 fun get_fillpats subst form errpatID thm =

   let

     val thmDeriv = Thm.get_name_hint thm

     val (part, thyID) = Rtools.thy_containing_thm thmDeriv

     val theID = [part, thyID, "Theorems", ThmC.cut_id thmDeriv]

     val fillpats = case Specify.get_the theID of

       Thy_Html.Hthm {fillpats, ...} => fillpats

     | _ => error "get_fillpats: uncovered case of get_the"

     val some = map (get_fillform subst (thm, form) errpatID) fillpats

   in some |> filter is_some |> map the end

 fun find_fillpatterns (pt, pos as (p, _): Pos.pos') errpatID =

   let 

     val f_curr = Ctree.get_curr_formula (pt, pos);

     val pp = Ctree.par_pblobj pt p

     val (errpats, prog) = case Specify.get_met (Ctree.get_obj Ctree.g_metID pt pp) of

       {errpats, scr = Rule.Prog prog, ...} => (errpats, prog)

     | _ => error "find_fillpatterns: uncovered case of get_met"

     val {env, ...} = Ctree.get_istate_LI pt pos |> Istate.the_pstate

     val subst = Rtools.get_bdv_subst prog env

     val errpatthms = errpats

       |> filter ((curry op = errpatID) o (#1: Error_Fill_Def.errpat -> Error_Fill_Def.errpatID))

       |> map (#3: Error_Fill_Def.errpat -> thm list)

       |> flat

   in map (get_fillpats subst f_curr errpatID) errpatthms |> flat end

 (* check if an input formula is exactly equal to the rewrite from a rule

    which is stored at the pos where the input is stored of "ok". *)

 fun is_exactly_equal (pt, pos as (p, _)) istr =

   case TermC.parseNEW (ThyC.get_theory "Isac_Knowledge" |> ThyC.to_ctxt) istr of

     NONE => ("syntax error in '" ^ istr ^ "'", Tactic.Tac "")

   | SOME ifo => 

       let

         val p' = Pos.lev_on p;

         val tac = Ctree.get_obj Ctree.g_tac pt p';

       in 

         case Applicable.applicable_in pos pt tac of

           Applicable.Notappl msg => (msg, Tactic.Tac "")

         | Applicable.Appl rew =>

             let

               val res = case rew of

                Tactic.Rewrite_Inst' (_, _, _, _, _, _, _, (res, _)) => res

               |Tactic.Rewrite' (_, _, _, _, _, _, (res, _)) => res

               | t => error ("is_exactly_equal: uncovered case for " ^ Tactic.string_of t)

             in 

               if not (ifo = res) then

                 ("input does not exactly fill the gaps", Tactic.Tac "")

               else ("ok", tac)

             end

       end

 (* fetch errpatIDs from an arbitrary tactic *)

 fun fetchErrorpatterns tac =

   let

     val rlsID =

       case tac of

        Tactic.Rewrite_Set rlsID => rlsID

       |Tactic.Rewrite_Set_Inst (_, rlsID) => rlsID

       | _ => "empty"

     val (part, thyID) = Rtools.thy_containing_rls "Isac_Knowledge" rlsID;

     val rls = case Specify.get_the [part, thyID, "Rulesets", rlsID] of

       Thy_Html.Hrls {thy_rls = (_, rls), ...} => rls

     | _ => error "fetchErrorpatterns: uncovered case of get_the"

   in case rls of

     Rule_Def.Repeat {errpatts, ...} => errpatts

   | Rule_Set.Sequence {errpatts, ...} => errpatts

   | Rule_Set.Rrls {errpatts, ...} => errpatts

   | Rule_Set.Empty => []

   end

 type errpatID = Rule_Def.errpatID

 type errpat =

   errpatID    (* one identifier for a list of patterns                       

                  DESIGN ?TODO: errpatID list for hierarchy of errpats ?      *)

   * term list (* error patterns                                              *)

   * thm list  (* thms related to error patterns; note that respective lhs 

                  do not match (which reflects student's error).

                  fillpatterns are stored with these thms.                    *)

 fun errpat2str (id, tms, thms) =

   "(\"" ^ id ^ "\",\n" ^ UnparseC.terms tms ^ ",\n" ^ ThmC.string_of_thms thms

 fun errpats2str errpats = (strs2str' o (map errpat2str)) errpats

 (**)end(**)