(*  Title:      HOL/Tools/record_package.ML

    ID:         $Id$

    Author:     Wolfgang Naraschewski, Norbert Schirmer and Markus Wenzel, TU Muenchen

Extensible records with structural subtyping in HOL.

*)

signature BASIC_RECORD_PACKAGE =

sig

  val record_simproc: simproc

  val record_eq_simproc: simproc

  val record_upd_simproc: simproc

  val record_split_simproc: (term -> int) -> simproc

  val record_ex_sel_eq_simproc: simproc

  val record_split_tac: int -> tactic

  val record_split_simp_tac: thm list -> (term -> int) -> int -> tactic

  val record_split_name: string

  val record_split_wrapper: string * wrapper

  val print_record_type_abbr: bool ref

  val print_record_type_as_fields: bool ref

end;

signature RECORD_PACKAGE =

sig

  include BASIC_RECORD_PACKAGE

  val quiet_mode: bool ref

  val record_quick_and_dirty_sensitive: bool ref

  val updateN: string

  val ext_typeN: string

  val last_extT: typ -> (string * typ list) option

  val dest_recTs : typ -> (string * typ list) list

  val get_extT_fields:  theory -> typ -> ((string * typ) list * (string * typ))

  val get_recT_fields:  theory -> typ -> ((string * typ) list * (string * typ))

  val get_extension: theory -> Symtab.key -> (string * typ list) option

  val get_extinjects: theory -> thm list

  val get_simpset: theory -> simpset

  val print_records: theory -> unit

  val add_record: string list * string -> string option -> (string * string * mixfix) list

    -> theory -> theory

  val add_record_i: string list * string -> (typ list * string) option

    -> (string * typ * mixfix) list -> theory -> theory

  val setup: theory -> theory

end;

structure RecordPackage: RECORD_PACKAGE =

struct

val rec_UNIV_I = thm "rec_UNIV_I";

val rec_True_simp = thm "rec_True_simp";

val Pair_eq = thm "Product_Type.Pair_eq";

val atomize_all = thm "HOL.atomize_all";

val atomize_imp = thm "HOL.atomize_imp";

val meta_allE = thm "Pure.meta_allE";

val prop_subst = thm "prop_subst";

val Pair_sel_convs = [fst_conv,snd_conv];

(** name components **)

val rN = "r";

val wN = "w";

val moreN = "more";

val schemeN = "_scheme";

val ext_typeN = "_ext_type";

val extN ="_ext";

val casesN = "_cases";

val ext_dest = "_sel";

val updateN = "_update";

val updN = "_upd";

val schemeN = "_scheme";

val makeN = "make";

val fields_selN = "fields";

val extendN = "extend";

val truncateN = "truncate";

(*see typedef_package.ML*)

val RepN = "Rep_";

val AbsN = "Abs_";

(*** utilities ***)

fun but_last xs = fst (split_last xs);

fun varifyT midx =

  let fun varify (a, S) = TVar ((a, midx + 1), S);

  in map_type_tfree varify end;

(* messages *)

val quiet_mode = ref false;

fun message s = if ! quiet_mode then () else writeln s;

(* timing *)

fun timeit_msg s x = if !timing then (warning s; timeit x) else x ();

fun timing_msg s = if !timing then warning s else ();

(* syntax *)

fun prune n xs = Library.drop (n, xs);

fun prefix_base s = NameSpace.map_base (fn bname => s ^ bname);

val Trueprop = HOLogic.mk_Trueprop;

fun All xs t = Term.list_all_free (xs, t);

infix 9 $$;

infix 0 :== ===;

infixr 0 ==>;

val (op $$) = Term.list_comb;

val (op :==) = Logic.mk_defpair;

val (op ===) = Trueprop o HOLogic.mk_eq;

val (op ==>) = Logic.mk_implies;

(* morphisms *)

fun mk_RepN name = suffix ext_typeN (prefix_base RepN name);

fun mk_AbsN name = suffix ext_typeN (prefix_base AbsN name);

fun mk_Rep name repT absT  =

  Const (suffix ext_typeN (prefix_base RepN name),absT --> repT);

fun mk_Abs name repT absT =

  Const (mk_AbsN name,repT --> absT);

(* constructor *)

fun mk_extC (name,T) Ts  = (suffix extN name, Ts ---> T);

fun mk_ext (name,T) ts =

  let val Ts = map fastype_of ts

  in list_comb (Const (mk_extC (name,T) Ts),ts) end;

(* cases *)

fun mk_casesC (name,T,vT) Ts = (suffix casesN name, (Ts ---> vT) --> T --> vT)

fun mk_cases (name,T,vT) f =

  let val Ts = binder_types (fastype_of f)

  in Const (mk_casesC (name,T,vT) Ts) $ f end;

(* selector *)

fun mk_selC sT (c,T) = (c,sT --> T);

fun mk_sel s (c,T) =

  let val sT = fastype_of s

  in Const (mk_selC sT (c,T)) $ s end;

(* updates *)

fun mk_updC sfx sT (c,T) = (suffix sfx c, T --> sT --> sT);

fun mk_upd sfx c v s =

  let val sT = fastype_of s;

      val vT = fastype_of v;

  in Const (mk_updC sfx sT (c, vT)) $ v $ s end;

(* types *)

fun dest_recT (typ as Type (c_ext_type, Ts as (T::_))) =

      (case try (unsuffix ext_typeN) c_ext_type of

        NONE => raise TYPE ("RecordPackage.dest_recT", [typ], [])

      | SOME c => ((c, Ts), List.last Ts))

  | dest_recT typ = raise TYPE ("RecordPackage.dest_recT", [typ], []);

fun is_recT T =

  (case try dest_recT T of NONE => false | SOME _ => true);

fun dest_recTs T =

  let val ((c, Ts), U) = dest_recT T

  in (c, Ts) :: dest_recTs U

  end handle TYPE _ => [];

fun last_extT T =

  let val ((c, Ts), U) = dest_recT T

  in (case last_extT U of

        NONE => SOME (c,Ts)

      | SOME l => SOME l)

  end handle TYPE _ => NONE

fun rec_id i T =

  let val rTs = dest_recTs T

      val rTs' = if i < 0 then rTs else Library.take (i,rTs)

  in Library.foldl (fn (s,(c,T)) => s ^ c) ("",rTs') end;

(*** extend theory by record definition ***)

(** record info **)

(* type record_info and parent_info  *)

type record_info =

 {args: (string * sort) list,

  parent: (typ list * string) option,

  fields: (string * typ) list,

  extension: (string * typ list),

  induct: thm

 };

fun make_record_info args parent fields extension induct =

 {args = args, parent = parent, fields = fields, extension = extension,

  induct = induct}: record_info;

type parent_info =

 {name: string,

  fields: (string * typ) list,

  extension: (string * typ list),

  induct: thm

};

fun make_parent_info name fields extension induct =

 {name = name, fields = fields, extension = extension, induct = induct}: parent_info;

(* data kind 'HOL/record' *)

type record_data =

 {records: record_info Symtab.table,

  sel_upd:

   {selectors: unit Symtab.table,

    updates: string Symtab.table,

    simpset: Simplifier.simpset},

  equalities: thm Symtab.table,

  extinjects: thm list,

  extsplit: thm Symtab.table, (* maps extension name to split rule *)

  splits: (thm*thm*thm*thm) Symtab.table,    (* !!,!,EX - split-equalities,induct rule *)

  extfields: (string*typ) list Symtab.table, (* maps extension to its fields *)

  fieldext: (string*typ list) Symtab.table   (* maps field to its extension *)

};

fun make_record_data

      records sel_upd equalities extinjects extsplit splits extfields fieldext =

 {records = records, sel_upd = sel_upd,

  equalities = equalities, extinjects=extinjects, extsplit = extsplit, splits = splits,

  extfields = extfields, fieldext = fieldext }: record_data;

structure RecordsData = TheoryDataFun

(struct

  val name = "HOL/records";

  type T = record_data;

  val empty =

    make_record_data Symtab.empty

      {selectors = Symtab.empty, updates = Symtab.empty, simpset = HOL_basic_ss}

       Symtab.empty [] Symtab.empty Symtab.empty Symtab.empty Symtab.empty;

  val copy = I;

  val extend = I;

  fun merge _

   ({records = recs1,

     sel_upd = {selectors = sels1, updates = upds1, simpset = ss1},

     equalities = equalities1,

     extinjects = extinjects1,

     extsplit = extsplit1,

     splits = splits1,

     extfields = extfields1,

     fieldext = fieldext1},

    {records = recs2,

     sel_upd = {selectors = sels2, updates = upds2, simpset = ss2},

     equalities = equalities2,

     extinjects = extinjects2,

     extsplit = extsplit2,

     splits = splits2,

     extfields = extfields2,

     fieldext = fieldext2}) =

    make_record_data

      (Symtab.merge (K true) (recs1, recs2))

      {selectors = Symtab.merge (K true) (sels1, sels2),

        updates = Symtab.merge (K true) (upds1, upds2),

        simpset = Simplifier.merge_ss (ss1, ss2)}

      (Symtab.merge Thm.eq_thm (equalities1, equalities2))

      (gen_merge_lists Thm.eq_thm extinjects1 extinjects2)

      (Symtab.merge Thm.eq_thm (extsplit1,extsplit2))

      (Symtab.merge (fn ((a,b,c,d),(w,x,y,z))

                     => Thm.eq_thm (a,w) andalso Thm.eq_thm (b,x) andalso

                        Thm.eq_thm (c,y) andalso Thm.eq_thm (d,z))

                    (splits1, splits2))

      (Symtab.merge (K true) (extfields1,extfields2))

      (Symtab.merge (K true) (fieldext1,fieldext2));

  fun print thy ({records = recs, ...}: record_data) =

    let

      val prt_typ = Sign.pretty_typ thy;

      fun pretty_parent NONE = []

        | pretty_parent (SOME (Ts, name)) =

            [Pretty.block [prt_typ (Type (name, Ts)), Pretty.str " +"]];

      fun pretty_field (c, T) = Pretty.block

        [Pretty.str (Sign.extern_const thy c), Pretty.str " ::",

          Pretty.brk 1, Pretty.quote (prt_typ T)];

      fun pretty_record (name, {args, parent, fields, ...}: record_info) =

        Pretty.block (Pretty.fbreaks (Pretty.block

          [prt_typ (Type (name, map TFree args)), Pretty.str " = "] ::

          pretty_parent parent @ map pretty_field fields));

    in map pretty_record (Symtab.dest recs) |> Pretty.chunks |> Pretty.writeln end;

end);

val print_records = RecordsData.print;

(* access 'records' *)

val get_record = Symtab.lookup o #records o RecordsData.get;

fun put_record name info thy =

  let

    val {records, sel_upd, equalities, extinjects,extsplit,splits,extfields,fieldext} =

          RecordsData.get thy;

    val data = make_record_data (Symtab.update (name, info) records)

      sel_upd equalities extinjects extsplit splits extfields fieldext;

  in RecordsData.put data thy end;

(* access 'sel_upd' *)

val get_sel_upd = #sel_upd o RecordsData.get;

val is_selector = Symtab.defined o #selectors o get_sel_upd;

val get_updates = Symtab.lookup o #updates o get_sel_upd;

fun get_simpset thy = Simplifier.theory_context thy (#simpset (get_sel_upd thy));

fun put_sel_upd names simps thy =

  let

    val sels = map (rpair ()) names;

    val upds = map (suffix updateN) names ~~ names;

    val {records, sel_upd = {selectors, updates, simpset},

      equalities, extinjects, extsplit, splits, extfields,fieldext} = RecordsData.get thy;

    val data = make_record_data records

      {selectors = Symtab.extend (selectors, sels),

        updates = Symtab.extend (updates, upds),

        simpset = Simplifier.addsimps (simpset, simps)}

       equalities extinjects extsplit splits extfields fieldext;

  in RecordsData.put data thy end;

(* access 'equalities' *)

fun add_record_equalities name thm thy =

  let

    val {records, sel_upd, equalities, extinjects, extsplit, splits, extfields,fieldext} =

          RecordsData.get thy;

    val data = make_record_data records sel_upd

           (Symtab.update_new (name, thm) equalities) extinjects extsplit

           splits extfields fieldext;

  in RecordsData.put data thy end;

val get_equalities =Symtab.lookup o #equalities o RecordsData.get;

(* access 'extinjects' *)

fun add_extinjects thm thy =

  let

    val {records, sel_upd, equalities, extinjects, extsplit, splits, extfields,fieldext} =

          RecordsData.get thy;

    val data = make_record_data records sel_upd equalities (extinjects@[thm]) extsplit

                 splits extfields fieldext;

  in RecordsData.put data thy end;

fun get_extinjects thy = #extinjects (RecordsData.get thy);

(* access 'extsplit' *)

fun add_extsplit name thm thy =

  let

    val {records, sel_upd, equalities, extinjects, extsplit, splits, extfields,fieldext} =

          RecordsData.get thy;

    val data = make_record_data records sel_upd

      equalities extinjects (Symtab.update_new (name, thm) extsplit) splits

      extfields fieldext;

  in RecordsData.put data thy end;

val get_extsplit = Symtab.lookup o #extsplit o RecordsData.get;

(* access 'splits' *)

fun add_record_splits name thmP thy =

  let

    val {records, sel_upd, equalities, extinjects, extsplit, splits, extfields,fieldext} =

          RecordsData.get thy;

    val data = make_record_data records sel_upd

      equalities extinjects extsplit (Symtab.update_new (name, thmP) splits)

      extfields fieldext;

  in RecordsData.put data thy end;

val get_splits = Symtab.lookup o #splits o RecordsData.get;

(* extension of a record name *)

val get_extension =

  Option.map #extension oo (Symtab.lookup o #records o RecordsData.get);

(* access 'extfields' *)

fun add_extfields name fields thy =

  let

    val {records, sel_upd, equalities, extinjects, extsplit,splits, extfields, fieldext} =

          RecordsData.get thy;

    val data = make_record_data records sel_upd

         equalities extinjects extsplit splits

         (Symtab.update_new (name, fields) extfields) fieldext;

  in RecordsData.put data thy end;

val get_extfields = Symtab.lookup o #extfields o RecordsData.get;

fun get_extT_fields thy T =

  let

    val ((name,Ts),moreT) = dest_recT T;

    val recname = let val (nm::recn::rst) = rev (NameSpace.unpack name)

                  in NameSpace.pack (rev (nm::rst)) end;

    val midx = maxidx_of_typs (moreT::Ts);

    val varifyT = varifyT midx;

    val {records,extfields,...} = RecordsData.get thy;

    val (flds,(more,_)) = split_last (Symtab.lookup_list extfields name);

    val args = map varifyT (snd (#extension (the (Symtab.lookup records recname))));

    val subst = fold (Sign.typ_match thy) (but_last args ~~ but_last Ts) (Vartab.empty);

    val flds' = map (apsnd ((Envir.norm_type subst) o varifyT)) flds;

  in (flds',(more,moreT)) end;

fun get_recT_fields thy T =

  let

    val (root_flds,(root_more,root_moreT)) = get_extT_fields thy T;

    val (rest_flds,rest_more) =

           if is_recT root_moreT then get_recT_fields thy root_moreT

           else ([],(root_more,root_moreT));

  in (root_flds@rest_flds,rest_more) end;

(* access 'fieldext' *)

fun add_fieldext extname_types fields thy =

  let

    val {records, sel_upd, equalities, extinjects, extsplit, splits, extfields, fieldext} =

           RecordsData.get thy;

    val fieldext' =

      fold (fn field => Symtab.update_new (field, extname_types)) fields fieldext;

    val data=make_record_data records sel_upd equalities extinjects extsplit

              splits extfields fieldext';

  in RecordsData.put data thy end;

val get_fieldext = Symtab.lookup o #fieldext o RecordsData.get;

(* parent records *)

fun add_parents thy NONE parents = parents

  | add_parents thy (SOME (types, name)) parents =

      let

        val sign = Theory.sign_of thy;

        fun err msg = error (msg ^ " parent record " ^ quote name);

        val {args, parent, fields, extension, induct} =

          (case get_record thy name of SOME info => info | NONE => err "Unknown");

        val _ = if length types <> length args then err "Bad number of arguments for" else ();

        fun bad_inst ((x, S), T) =

          if Sign.of_sort sign (T, S) then NONE else SOME x

        val bads = List.mapPartial bad_inst (args ~~ types);

        val inst = map fst args ~~ types;

        val subst = Term.map_type_tfree (the o AList.lookup (op =) inst o fst);

        val parent' = Option.map (apfst (map subst)) parent;

        val fields' = map (apsnd subst) fields;

        val extension' = apsnd (map subst) extension;

      in

        conditional (not (null bads)) (fn () =>

          err ("Ill-sorted instantiation of " ^ commas bads ^ " in"));

        add_parents thy parent'

          (make_parent_info name fields' extension' induct::parents)

      end;

(** concrete syntax for records **)

(* parse translations *)

fun gen_field_tr mark sfx (t as Const (c, _) $ Const (name, _) $ arg) =

      if c = mark then Syntax.const (suffix sfx name) $ arg

      else raise TERM ("gen_field_tr: " ^ mark, [t])

  | gen_field_tr mark _ t = raise TERM ("gen_field_tr: " ^ mark, [t]);

fun gen_fields_tr sep mark sfx (tm as Const (c, _) $ t $ u) =

      if c = sep then gen_field_tr mark sfx t :: gen_fields_tr sep mark sfx u

      else [gen_field_tr mark sfx tm]

  | gen_fields_tr _ mark sfx tm = [gen_field_tr mark sfx tm];

fun record_update_tr [t, u] =

      foldr (op $) t (rev (gen_fields_tr "_updates" "_update" updateN u))

  | record_update_tr ts = raise TERM ("record_update_tr", ts);

fun update_name_tr (Free (x, T) :: ts) = Free (suffix updateN x, T) $$ ts

  | update_name_tr (Const (x, T) :: ts) = Const (suffix updateN x, T) $$ ts

  | update_name_tr (((c as Const ("_constrain", _)) $ t $ ty) :: ts) =

      (c $ update_name_tr [t] $ (Syntax.const "fun" $ ty $ Syntax.const "dummy")) $$ ts

  | update_name_tr ts = raise TERM ("update_name_tr", ts);

fun dest_ext_field mark (t as (Const (c,_) $ Const (name,_) $ arg)) =

     if c = mark then (name,arg) else raise TERM ("dest_ext_field: " ^ mark, [t])

  | dest_ext_field _ t = raise TERM ("dest_ext_field", [t])

fun dest_ext_fields sep mark (trm as (Const (c,_) $ t $ u)) =

     if c = sep then dest_ext_field mark t::dest_ext_fields sep mark u

     else [dest_ext_field mark trm]

  | dest_ext_fields _ mark t = [dest_ext_field mark t]

fun gen_ext_fields_tr sep mark sfx more context t =

  let

    val thy = Context.theory_of context;

    val msg = "error in record input: ";

    val fieldargs = dest_ext_fields sep mark t;

    fun splitargs (field::fields) ((name,arg)::fargs) =

          if can (unsuffix name) field

          then let val (args,rest) = splitargs fields fargs

               in (arg::args,rest) end

          else raise TERM (msg ^ "expecting field " ^ field ^ " but got " ^ name, [t])

      | splitargs [] (fargs as (_::_)) = ([],fargs)

      | splitargs (_::_) [] = raise TERM (msg ^ "expecting more fields", [t])

      | splitargs _ _ = ([],[]);

    fun mk_ext (fargs as (name,arg)::_) =

         (case get_fieldext thy (Sign.intern_const thy name) of

            SOME (ext,_) => (case get_extfields thy ext of

                               SOME flds

                                 => let val (args,rest) =

                                               splitargs (map fst (but_last flds)) fargs;

                                        val more' = mk_ext rest;

                                    in list_comb (Syntax.const (suffix sfx ext),args@[more'])

                                    end

                             | NONE => raise TERM(msg ^ "no fields defined for "

                                                   ^ ext,[t]))

          | NONE => raise TERM (msg ^ name ^" is no proper field",[t]))

      | mk_ext [] = more

  in mk_ext fieldargs end;

fun gen_ext_type_tr sep mark sfx more context t =

  let

    val thy = Context.theory_of context;

    val msg = "error in record-type input: ";

    val fieldargs = dest_ext_fields sep mark t;

    fun splitargs (field::fields) ((name,arg)::fargs) =

          if can (unsuffix name) field

          then let val (args,rest) = splitargs fields fargs

               in (arg::args,rest) end

          else raise TERM (msg ^ "expecting field " ^ field ^ " but got " ^ name, [t])

      | splitargs [] (fargs as (_::_)) = ([],fargs)

      | splitargs (_::_) [] = raise TERM (msg ^ "expecting more fields", [t])

      | splitargs _ _ = ([],[]);

    fun get_sort xs n = AList.lookup (op =) xs n |> the_default (Sign.defaultS thy);

    fun to_type t = Sign.certify_typ thy

                       (Sign.intern_typ thy

                         (Syntax.typ_of_term (get_sort (Syntax.raw_term_sorts t)) I t));

    fun mk_ext (fargs as (name,arg)::_) =

         (case get_fieldext thy (Sign.intern_const thy name) of

            SOME (ext,alphas) =>

              (case get_extfields thy ext of

                 SOME flds

                  => (let

                       val flds' = but_last flds;

                       val types = map snd flds';

                       val (args,rest) = splitargs (map fst flds') fargs;

                       val argtypes = map to_type args;

                       val midx =  fold (fn T => fn i => Int.max (maxidx_of_typ T, i)) 

                                    argtypes 0;

                       val varifyT = varifyT midx;

                       val vartypes = map varifyT types;

                       val subst = fold (Sign.typ_match thy) (vartypes ~~ argtypes)

                                            Vartab.empty;

                       val alphas' = map ((Syntax.term_of_typ (! Syntax.show_sorts)) o

                                          Envir.norm_type subst o varifyT)

                                         (but_last alphas);

                       val more' = mk_ext rest;

                     in list_comb (Syntax.const (suffix sfx ext),alphas'@[more'])

                     end handle TYPE_MATCH => raise

                           TERM (msg ^ "type is no proper record (extension)", [t]))

               | NONE => raise TERM (msg ^ "no fields defined for " ^ ext,[t]))

          | NONE => raise TERM (msg ^ name ^" is no proper field",[t]))

      | mk_ext [] = more

  in mk_ext fieldargs end;

fun gen_adv_record_tr sep mark sfx unit context [t] =

      gen_ext_fields_tr sep mark sfx unit context t

  | gen_adv_record_tr _ _ _ _ _ ts = raise TERM ("gen_record_tr", ts);

fun gen_adv_record_scheme_tr sep mark sfx context [t, more] =

      gen_ext_fields_tr sep mark sfx more context t

  | gen_adv_record_scheme_tr _ _ _ _ ts = raise TERM ("gen_record_scheme_tr", ts);

fun gen_adv_record_type_tr sep mark sfx unit context [t] =

      gen_ext_type_tr sep mark sfx unit context t

  | gen_adv_record_type_tr _ _ _ _ _ ts = raise TERM ("gen_record_tr", ts);

fun gen_adv_record_type_scheme_tr sep mark sfx context [t, more] =

      gen_ext_type_tr sep mark sfx more context t

  | gen_adv_record_type_scheme_tr _ _ _ _ ts = raise TERM ("gen_record_scheme_tr", ts);

val adv_record_tr = gen_adv_record_tr "_fields" "_field" extN HOLogic.unit;

val adv_record_scheme_tr = gen_adv_record_scheme_tr "_fields" "_field" extN;

val adv_record_type_tr =

      gen_adv_record_type_tr "_field_types" "_field_type" ext_typeN

        (Syntax.term_of_typ false (HOLogic.unitT));

val adv_record_type_scheme_tr =

      gen_adv_record_type_scheme_tr "_field_types" "_field_type" ext_typeN;

val parse_translation =

 [("_record_update", record_update_tr),

  ("_update_name", update_name_tr)];

val adv_parse_translation =

 [("_record",adv_record_tr),

  ("_record_scheme",adv_record_scheme_tr),

  ("_record_type",adv_record_type_tr),

  ("_record_type_scheme",adv_record_type_scheme_tr)];

(* print translations *)

val print_record_type_abbr = ref true;

val print_record_type_as_fields = ref true;

fun gen_field_upds_tr' mark sfx (tm as Const (name_field, _) $ t $ u) =

    (case try (unsuffix sfx) name_field of

      SOME name =>

        apfst (cons (Syntax.const mark $ Syntax.free name $ t)) (gen_field_upds_tr' mark sfx u)

     | NONE => ([], tm))

  | gen_field_upds_tr' _ _ tm = ([], tm);

fun record_update_tr' tm =

  let val (ts, u) = gen_field_upds_tr' "_update" updateN tm in

    Syntax.const "_record_update" $ u $

      foldr1 (fn (v, w) => Syntax.const "_updates" $ v $ w) (rev ts)

  end;

fun gen_field_tr' sfx tr' name =

  let val name_sfx = suffix sfx name

  in (name_sfx, fn [t, u] => tr' (Syntax.const name_sfx $ t $ u) | _ => raise Match) end;

fun record_tr' sep mark record record_scheme unit context t =

  let

    val thy = Context.theory_of context;

    fun field_lst t =

      (case strip_comb t of

        (Const (ext,_),args as (_::_))

         => (case try (unsuffix extN) (Sign.intern_const thy ext) of

               SOME ext'

               => (case get_extfields thy ext' of

                     SOME flds

                     => (let

                          val (f::fs) = but_last (map fst flds);

                          val flds' = Sign.extern_const thy f :: map NameSpace.base fs;

                          val (args',more) = split_last args;

                         in (flds'~~args')@field_lst more end

                         handle Library.UnequalLengths => [("",t)])

                   | NONE => [("",t)])

             | NONE => [("",t)])

       | _ => [("",t)])

    val (flds,(_,more)) = split_last (field_lst t);

    val flds' = map (fn (n,t)=>Syntax.const mark$Syntax.const n$t) flds;

    val flds'' = foldr1 (fn (x,y) => Syntax.const sep$x$y) flds';

  in if null flds then raise Match

     else if unit more

          then Syntax.const record$flds''

          else Syntax.const record_scheme$flds''$more

  end

fun gen_record_tr' name =

  let val name_sfx = suffix extN name;

      val unit = (fn Const ("Unity",_) => true | _ => false);

      fun tr' context ts = record_tr' "_fields" "_field" "_record" "_record_scheme" unit context

                       (list_comb (Syntax.const name_sfx,ts))

  in (name_sfx,tr')

  end

fun print_translation names =

  map (gen_field_tr' updateN record_update_tr') names;

(* record_type_abbr_tr' tries to reconstruct the record name type abbreviation from *)

(* the (nested) extension types.                                                    *)

fun record_type_abbr_tr' default_tr' abbr alphas zeta lastExt schemeT context tm =

  let

      val thy = Context.theory_of context;

      (* tm is term representation of a (nested) field type. We first reconstruct the      *)

      (* type from tm so that we can continue on the type level rather then the term level.*)

      fun get_sort xs n = AList.lookup (op =) xs n |> the_default (Sign.defaultS thy);

      (* WORKAROUND:

       * If a record type occurs in an error message of type inference there

       * may be some internal frees donoted by ??:

       * (Const "_tfree",_)$Free ("??'a",_).

       * This will unfortunately be translated to Type ("??'a",[]) instead of

       * TFree ("??'a",_) by typ_of_term, which will confuse unify below.

       * fixT works around.

       *)

      fun fixT (T as Type (x,[])) =

            if String.isPrefix "??'" x then TFree (x,Sign.defaultS thy) else T

        | fixT (Type (x,xs)) = Type (x,map fixT xs)

        | fixT T = T;

      val T = fixT (Sign.intern_typ thy

                      (Syntax.typ_of_term (get_sort (Syntax.raw_term_sorts tm)) I tm));

      val midx = maxidx_of_typ T;

      val varifyT = varifyT midx;

      fun mk_type_abbr subst name alphas =

          let val abbrT = Type (name, map (fn a => varifyT (TFree (a, Sign.defaultS thy))) alphas);

          in Syntax.term_of_typ (! Syntax.show_sorts)

               (Sign.extern_typ thy (Envir.norm_type subst abbrT)) end;

      fun match rT T = (Sign.typ_match thy (varifyT rT,T) 

                                                Vartab.empty);

   in if !print_record_type_abbr

      then (case last_extT T of

             SOME (name,_)

              => if name = lastExt

                 then

                  (let

                     val subst = match schemeT T

                   in

                    if HOLogic.is_unitT (Envir.norm_type subst (varifyT (TFree(zeta,Sign.defaultS thy))))

                    then mk_type_abbr subst abbr alphas

                    else mk_type_abbr subst (suffix schemeN abbr) (alphas@[zeta])

                   end handle TYPE_MATCH => default_tr' context tm)

                 else raise Match (* give print translation of specialised record a chance *)

            | _ => raise Match)

       else default_tr' context tm

  end

fun record_type_tr' sep mark record record_scheme context t =

  let

    val thy = Context.theory_of context;

    fun get_sort xs n = AList.lookup (op =) xs n |> the_default (Sign.defaultS thy);

    val T = Sign.intern_typ thy (Syntax.typ_of_term (get_sort (Syntax.raw_term_sorts t)) I t)

    val varifyT = varifyT (Term.maxidx_of_typ T)

    fun term_of_type T = Syntax.term_of_typ (!Syntax.show_sorts) (Sign.extern_typ thy T);

    fun field_lst T =

      (case T of

        Type (ext,args)

         => (case try (unsuffix ext_typeN) ext of

               SOME ext'

               => (case get_extfields thy ext' of

                     SOME flds

                     => (case get_fieldext thy (fst (hd flds)) of

                           SOME (_,alphas)

                           => (let

                                val (f::fs) = but_last flds;

                                val flds' = apfst (Sign.extern_const thy) f

                                            ::map (apfst NameSpace.base) fs;

                                val (args',more) = split_last args;

                                val alphavars = map varifyT (but_last alphas);

                                val subst= fold (Sign.typ_match thy) (alphavars~~args')

                                                    Vartab.empty;

                                val flds'' =map (apsnd (Envir.norm_type subst o varifyT))

                                                flds';

                              in flds''@field_lst more end

                              handle TYPE_MATCH     => [("",T)]

                                   | Library.UnequalLengths => [("",T)])

                         | NONE => [("",T)])

                   | NONE => [("",T)])

             | NONE => [("",T)])

        | _ => [("",T)])

    val (flds,(_,moreT)) = split_last (field_lst T);

    val flds' = map (fn (n,T)=>Syntax.const mark$Syntax.const n$term_of_type T) flds;

    val flds'' = foldr1 (fn (x,y) => Syntax.const sep$x$y) flds';

  in if not (!print_record_type_as_fields) orelse null flds then raise Match

     else if moreT = HOLogic.unitT

          then Syntax.const record$flds''

          else Syntax.const record_scheme$flds''$term_of_type moreT

  end

fun gen_record_type_tr' name =

  let val name_sfx = suffix ext_typeN name;

      fun tr' context ts = record_type_tr' "_field_types" "_field_type"

                       "_record_type" "_record_type_scheme" context

                       (list_comb (Syntax.const name_sfx,ts))

  in (name_sfx,tr')

  end

fun gen_record_type_abbr_tr' abbr alphas zeta lastExt schemeT name =

  let val name_sfx = suffix ext_typeN name;

      val default_tr' = record_type_tr' "_field_types" "_field_type"

                               "_record_type" "_record_type_scheme"

      fun tr' context ts =

          record_type_abbr_tr' default_tr' abbr alphas zeta lastExt schemeT context

                               (list_comb (Syntax.const name_sfx,ts))

  in (name_sfx, tr') end;

(** record simprocs **)

val record_quick_and_dirty_sensitive = ref false;

fun quick_and_dirty_prove stndrd thy asms prop tac =

  if !record_quick_and_dirty_sensitive andalso !quick_and_dirty

  then Goal.prove (ProofContext.init thy) [] []

        (Logic.list_implies (map Logic.varify asms,Logic.varify prop))

        (K (SkipProof.cheat_tac HOL.thy))

        (* standard can take quite a while for large records, thats why

         * we varify the proposition manually here.*)

  else let val prf = Goal.prove (ProofContext.init thy) [] asms prop tac;

       in if stndrd then standard prf else prf end;

fun quick_and_dirty_prf noopt opt () =

      if !record_quick_and_dirty_sensitive andalso !quick_and_dirty

      then noopt ()

      else opt ();

fun prove_split_simp thy ss T prop =

  let

    val {sel_upd={simpset,...},extsplit,...} = RecordsData.get thy;

    val extsplits =

            Library.foldl (fn (thms,(n,_)) => the_list (Symtab.lookup extsplit n) @ thms)

                    ([],dest_recTs T);

    val thms = (case get_splits thy (rec_id (~1) T) of

                   SOME (all_thm,_,_,_) =>

                     all_thm::(case extsplits of [thm] => [] | _ => extsplits)

                              (* [thm] is the same as all_thm *)

                 | NONE => extsplits)

  in

    quick_and_dirty_prove true thy [] prop

      (fn _ => simp_tac (Simplifier.inherit_context ss simpset addsimps thms) 1)

  end;

local

fun eq (s1:string) (s2:string) = (s1 = s2);

fun has_field extfields f T =

     exists (fn (eN,_) => exists (eq f o fst) (Symtab.lookup_list extfields eN))

       (dest_recTs T);

in

(* record_simproc *)

(* Simplifies selections of an record update:

 *  (1)  S (r(|S:=k|)) = k respectively

 *  (2)  S (r(|X:=k|)) = S r

 * The simproc skips multiple updates at once, eg:

 *  S (r (|S:=k,X:=2,Y:=3|)) = k

 * But be careful in (2) because of the extendibility of records.

 * - If S is a more-selector we have to make sure that the update on component

 *   X does not affect the selected subrecord.

 * - If X is a more-selector we have to make sure that S is not in the updated

 *   subrecord.

 *)

val record_simproc =

  Simplifier.simproc HOL.thy "record_simp" ["x"]

    (fn thy => fn ss => fn t =>

      (case t of (sel as Const (s, Type (_,[domS,rangeS])))$

                   ((upd as Const (u,Type(_,[_,Type (_,[rT,_])]))) $ k $ r)=>

        if is_selector thy s then

          (case get_updates thy u of SOME u_name =>

            let

              val {sel_upd={updates,...},extfields,...} = RecordsData.get thy;

              fun mk_eq_terms ((upd as Const (u,Type(_,[kT,_]))) $ k $ r) =

                  (case Symtab.lookup updates u of

                     NONE => NONE

                   | SOME u_name

                     => if u_name = s

                        then let

                               val rv = ("r",rT)

                               val rb = Bound 0

                               val kv = ("k",kT)

                               val kb = Bound 1

                             in SOME (upd$kb$rb,kb,[kv,rv],true) end

                        else if has_field extfields u_name rangeS

                             orelse has_field extfields s kT

                             then NONE

                             else (case mk_eq_terms r of

                                     SOME (trm,trm',vars,update_s)

                                     => let

                                          val kv = ("k",kT)

                                          val kb = Bound (length vars)

                                        in SOME (upd$kb$trm,trm',kv::vars,update_s) end

                                   | NONE

                                     => let

                                          val rv = ("r",rT)

                                          val rb = Bound 0

                                          val kv = ("k",kT)

                                          val kb = Bound 1

                                        in SOME (upd$kb$rb,rb,[kv,rv],false) end))

                | mk_eq_terms r = NONE

            in

              (case mk_eq_terms (upd$k$r) of

                 SOME (trm,trm',vars,update_s)

                 => if update_s

                    then SOME (prove_split_simp thy ss domS

                                 (list_all(vars,(equals rangeS$(sel$trm)$trm'))))

                    else SOME (prove_split_simp thy ss domS

                                 (list_all(vars,(equals rangeS$(sel$trm)$(sel$trm')))))

               | NONE => NONE)

            end

          | NONE => NONE)

        else NONE

      | _ => NONE));

(* record_upd_simproc *)

(* simplify multiple updates:

 *  (1)  "r(|M:=3,N:=1,M:=2,N:=4|) == r(|M:=2,N:=4|)"

 *  (2)  "r(|M:= M r|) = r"

 * For (2) special care of "more" updates has to be taken:

 *    r(|more := m; A := A r|)

 * If A is contained in the fields of m we cannot remove the update A := A r!

 * (But r(|more := r; A := A (r(|more := r|))|) = r(|more := r|)

*)

val record_upd_simproc =

  Simplifier.simproc HOL.thy "record_upd_simp" ["x"]

    (fn thy => fn ss => fn t =>

      (case t of ((upd as Const (u, Type(_,[_,Type(_,[rT,_])]))) $ k $ r) =>

         let datatype ('a,'b) calc = Init of 'b | Inter of 'a

             val {sel_upd={selectors,updates,...},extfields,...} = RecordsData.get thy;

             (*fun mk_abs_var x t = (x, fastype_of t);*)

             fun sel_name u = NameSpace.base (unsuffix updateN u);

             fun seed s (upd as Const (more,Type(_,[mT,_]))$ k $ r) =

                  if has_field extfields s mT then upd else seed s r

               | seed _ r = r;

             fun grow u uT k kT vars (sprout,skeleton) =

                   if sel_name u = moreN

                   then let val kv = ("k", kT);

                            val kb = Bound (length vars);

                        in ((Const (u,uT)$k$sprout,Const (u,uT)$kb$skeleton),kv::vars) end

                   else ((sprout,skeleton),vars);

             fun is_upd_same (sprout,skeleton) u ((sel as Const (s,_))$r) =

                   if (unsuffix updateN u) = s andalso (seed s sprout) = r

                   then SOME (sel,seed s skeleton)

                   else NONE

               | is_upd_same _ _ _ = NONE

             fun init_seed r = ((r,Bound 0), [("r", rT)]);

             (* mk_updterm returns either

              *  - Init (orig-term, orig-term-skeleton, vars) if no optimisation can be made,

              *     where vars are the bound variables in the skeleton

              *  - Inter (orig-term-skeleton,simplified-term-skeleton,

              *           vars, (term-sprout, skeleton-sprout))

              *     where "All vars. orig-term-skeleton = simplified-term-skeleton" is

              *     the desired simplification rule,

              *     the sprouts accumulate the "more-updates" on the way from the seed

              *     to the outermost update. It is only relevant to calculate the

              *     possible simplification for (2)

              * The algorithm first walks down the updates to the seed-record while

              * memorising the updates in the already-table. While walking up the

              * updates again, the optimised term is constructed.

              *)

             fun mk_updterm upds already

                 (t as ((upd as Const (u,uT as (Type (_,[kT,_])))) $ k $ r)) =

                 if Symtab.defined upds u

                 then let

                         fun rest already = mk_updterm upds already

                      in if u mem_string already

                         then (case (rest already r) of

                                 Init ((sprout,skel),vars) =>

                                 let

                                   val kv = (sel_name u, kT);

                                   val kb = Bound (length vars);

                                   val (sprout',vars')= grow u uT k kT (kv::vars) (sprout,skel);

                                 in Inter (upd$kb$skel,skel,vars',sprout') end

                               | Inter (trm,trm',vars,sprout) =>

                                 let

                                   val kv = (sel_name u, kT);

                                   val kb = Bound (length vars);

                                   val (sprout',vars') = grow u uT k kT (kv::vars) sprout;

                                 in Inter(upd$kb$trm,trm',kv::vars',sprout') end)

                         else

                          (case rest (u::already) r of