(*  Title:      Pure/Isar/code.ML

    Author:     Florian Haftmann, TU Muenchen

Abstract executable content of theory.  Management of data dependent on

executable content.  Cache assumes non-concurrent processing of a single theory.

*)

signature CODE =

sig

  (*constructor sets*)

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

    -> string * ((string * sort) list * (string * typ list) list)

  (*typ instantiations*)

  val typscheme: theory -> string * typ -> (string * sort) list * typ

  val inst_thm: theory -> sort Vartab.table -> thm -> thm

  (*constants*)

  val string_of_typ: theory -> typ -> string

  val string_of_const: theory -> string -> string

  val no_args: theory -> string -> int

  val check_const: theory -> term -> string

  val read_bare_const: theory -> string -> string * typ

  val read_const: theory -> string -> string

  (*constant aliasses*)

  val add_const_alias: thm -> theory -> theory

  val triv_classes: theory -> class list

  val resubst_alias: theory -> string -> string

  (*code equations*)

  val mk_eqn: theory -> (string -> bool) -> thm * bool -> thm * bool

  val mk_eqn_warning: theory -> (string -> bool) -> thm -> (thm * bool) option

  val mk_eqn_liberal: theory -> (string -> bool) -> thm -> (thm * bool) option

  val assert_eqn: theory -> thm * bool -> thm * bool

  val assert_eqns_const: theory -> string

    -> (thm * bool) list -> (thm * bool) list

  val const_typ_eqn: thm -> string * typ

  val const_eqn: theory -> thm -> string

  val typscheme_eqn: theory -> thm -> (string * sort) list * typ

  val expand_eta: theory -> int -> thm -> thm

  val rewrite_eqn: simpset -> thm -> thm

  val rewrite_head: thm list -> thm -> thm

  val norm_args: theory -> thm list -> thm list 

  val norm_varnames: theory -> thm list -> thm list

  (*case certificates*)

  val case_cert: thm -> string * (int * string list)

  (*infrastructure*)

  val add_attribute: string * attribute parser -> theory -> theory

  val purge_data: theory -> theory

  (*executable content*)

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

  val add_datatype_cmd: string list -> theory -> theory

  val type_interpretation:

    (string * ((string * sort) list * (string * typ list) list)

      -> theory -> theory) -> theory -> theory

  val add_eqn: thm -> theory -> theory

  val add_nbe_eqn: thm -> theory -> theory

  val add_default_eqn: thm -> theory -> theory

  val add_default_eqn_attribute: attribute

  val add_default_eqn_attrib: Attrib.src

  val del_eqn: thm -> theory -> theory

  val del_eqns: string -> theory -> theory

  val add_eqnl: string * (thm * bool) list lazy -> theory -> theory

  val add_case: thm -> theory -> theory

  val add_undefined: string -> theory -> theory

  (*data retrieval*)

  val get_datatype: theory -> string -> ((string * sort) list * (string * typ list) list)

  val get_datatype_of_constr: theory -> string -> string option

  val default_typscheme: theory -> string -> (string * sort) list * typ

  val these_eqns: theory -> string -> (thm * bool) list

  val all_eqns: theory -> (thm * bool) list

  val get_case_scheme: theory -> string -> (int * (int * string list)) option

  val is_undefined: theory -> string -> bool

  val print_codesetup: theory -> unit

end;

signature CODE_DATA_ARGS =

sig

  type T

  val empty: T

  val purge: theory -> string list -> T -> T

end;

signature CODE_DATA =

sig

  type T

  val get: theory -> T

  val change: theory -> (T -> T) -> T

  val change_yield: theory -> (T -> 'a * T) -> 'a * T

end;

signature PRIVATE_CODE =

sig

  include CODE

  val declare_data: Object.T -> (theory -> string list -> Object.T -> Object.T)

    -> serial

  val get_data: serial * ('a -> Object.T) * (Object.T -> 'a)

    -> theory -> 'a

  val change_data: serial * ('a -> Object.T) * (Object.T -> 'a)

    -> theory -> ('a -> 'a) -> 'a

  val change_yield_data: serial * ('a -> Object.T) * (Object.T -> 'a)

    -> theory -> ('a -> 'b * 'a) -> 'b * 'a

end;

structure Code : PRIVATE_CODE =

struct

(* auxiliary *)

fun string_of_typ thy = setmp show_sorts true (Syntax.string_of_typ_global thy);

fun string_of_const thy c = case AxClass.inst_of_param thy c

 of SOME (c, tyco) => Sign.extern_const thy c ^ " " ^ enclose "[" "]" (Sign.extern_type thy tyco)

  | NONE => Sign.extern_const thy c;

fun no_args thy = length o fst o strip_type o Sign.the_const_type thy;

(* utilities *)

fun typscheme thy (c, ty) =

  let

    val ty' = Logic.unvarifyT ty;

    fun dest (TFree (v, sort)) = (v, sort)

      | dest ty = error ("Illegal type parameter in type scheme: " ^ Syntax.string_of_typ_global thy ty);

    val vs = map dest (Sign.const_typargs thy (c, ty'));

  in (vs, Type.strip_sorts ty') end;

fun inst_thm thy tvars' thm =

  let

    val tvars = (Term.add_tvars o Thm.prop_of) thm [];

    val inter_sort = Sorts.inter_sort (Sign.classes_of thy);

    fun mk_inst (tvar as (v, sort)) = case Vartab.lookup tvars' v

     of SOME sort' => SOME (pairself (Thm.ctyp_of thy o TVar)

          (tvar, (v, inter_sort (sort, sort'))))

      | NONE => NONE;

    val insts = map_filter mk_inst tvars;

  in Thm.instantiate (insts, []) thm end;

fun expand_eta thy k thm =

  let

    val (lhs, rhs) = (Logic.dest_equals o Thm.plain_prop_of) thm;

    val (head, args) = strip_comb lhs;

    val l = if k = ~1

      then (length o fst o strip_abs) rhs

      else Int.max (0, k - length args);

    val used = Name.make_context (map (fst o fst) (Term.add_vars lhs []));

    fun get_name _ 0 = pair []

      | get_name (Abs (v, ty, t)) k =

          Name.variants [v]

          ##>> get_name t (k - 1)

          #>> (fn ([v'], vs') => (v', ty) :: vs')

      | get_name t k = 

          let

            val (tys, _) = (strip_type o fastype_of) t

          in case tys

           of [] => raise TERM ("expand_eta", [t])

            | ty :: _ =>

                Name.variants [""]

                #-> (fn [v] => get_name (t $ Var ((v, 0), ty)) (k - 1)

                #>> (fn vs' => (v, ty) :: vs'))

          end;

    val (vs, _) = get_name rhs l used;

    fun expand (v, ty) thm = Drule.fun_cong_rule thm

      (Thm.cterm_of thy (Var ((v, 0), ty)));

  in

    thm

    |> fold expand vs

    |> Conv.fconv_rule Drule.beta_eta_conversion

  end;

fun eqn_conv conv =

  let

    fun lhs_conv ct = if can Thm.dest_comb ct

      then (Conv.combination_conv lhs_conv conv) ct

      else Conv.all_conv ct;

  in Conv.combination_conv (Conv.arg_conv lhs_conv) conv end;

fun head_conv conv =

  let

    fun lhs_conv ct = if can Thm.dest_comb ct

      then (Conv.fun_conv lhs_conv) ct

      else conv ct;

  in Conv.fun_conv (Conv.arg_conv lhs_conv) end;

val rewrite_eqn = Conv.fconv_rule o eqn_conv o Simplifier.rewrite;

val rewrite_head = Conv.fconv_rule o head_conv o MetaSimplifier.rewrite false;

fun norm_args thy thms =

  let

    val num_args_of = length o snd o strip_comb o fst o Logic.dest_equals;

    val k = fold (curry Int.max o num_args_of o Thm.prop_of) thms 0;

  in

    thms

    |> map (expand_eta thy k)

    |> map (Conv.fconv_rule Drule.beta_eta_conversion)

  end;

fun canonical_tvars thy thm =

  let

    val ctyp = Thm.ctyp_of thy;

    val purify_tvar = unprefix "'" #> Name.desymbolize false #> prefix "'";

    fun tvars_subst_for thm = (fold_types o fold_atyps)

      (fn TVar (v_i as (v, _), sort) => let

            val v' = purify_tvar v

          in if v = v' then I

          else insert (op =) (v_i, (v', sort)) end

        | _ => I) (prop_of thm) [];

    fun mk_inst (v_i, (v', sort)) (maxidx, acc) =

      let

        val ty = TVar (v_i, sort)

      in

        (maxidx + 1, (ctyp ty, ctyp (TVar ((v', maxidx), sort))) :: acc)

      end;

    val maxidx = Thm.maxidx_of thm + 1;

    val (_, inst) = fold mk_inst (tvars_subst_for thm) (maxidx + 1, []);

  in Thm.instantiate (inst, []) thm end;

fun canonical_vars thy thm =

  let

    val cterm = Thm.cterm_of thy;

    val purify_var = Name.desymbolize false;

    fun vars_subst_for thm = fold_aterms

      (fn Var (v_i as (v, _), ty) => let

            val v' = purify_var v

          in if v = v' then I

          else insert (op =) (v_i, (v', ty)) end

        | _ => I) (prop_of thm) [];

    fun mk_inst (v_i as (v, i), (v', ty)) (maxidx, acc) =

      let

        val t = Var (v_i, ty)

      in

        (maxidx + 1, (cterm t, cterm (Var ((v', maxidx), ty))) :: acc)

      end;

    val maxidx = Thm.maxidx_of thm + 1;

    val (_, inst) = fold mk_inst (vars_subst_for thm) (maxidx + 1, []);

  in Thm.instantiate ([], inst) thm end;

fun canonical_absvars thm =

  let

    val t = Thm.plain_prop_of thm;

    val purify_var = Name.desymbolize false;

    val t' = Term.map_abs_vars purify_var t;

  in Thm.rename_boundvars t t' thm end;

fun norm_varnames thy thms =

  let

    fun burrow_thms f [] = []

      | burrow_thms f thms =

          thms

          |> Conjunction.intr_balanced

          |> f

          |> Conjunction.elim_balanced (length thms)

  in

    thms

    |> map (canonical_vars thy)

    |> map canonical_absvars

    |> map Drule.zero_var_indexes

    |> burrow_thms (canonical_tvars thy)

    |> Drule.zero_var_indexes_list

  end;

(* const aliasses *)

structure ConstAlias = TheoryDataFun

(

  type T = ((string * string) * thm) list * class list;

  val empty = ([], []);

  val copy = I;

  val extend = I;

  fun merge _ ((alias1, classes1), (alias2, classes2)) : T =

    (Library.merge (eq_snd Thm.eq_thm_prop) (alias1, alias2),

      Library.merge (op =) (classes1, classes2));

);

fun add_const_alias thm thy =

  let

    val lhs_rhs = case try Logic.dest_equals (Thm.prop_of thm)

     of SOME lhs_rhs => lhs_rhs

      | _ => error ("Not an equation: " ^ Display.string_of_thm thm);

    val c_c' = case try (pairself (AxClass.unoverload_const thy o dest_Const)) lhs_rhs

     of SOME c_c' => c_c'

      | _ => error ("Not an equation with two constants: " ^ Display.string_of_thm thm);

    val some_class = the_list (AxClass.class_of_param thy (snd c_c'));

  in thy |>

    ConstAlias.map (fn (alias, classes) =>

      ((c_c', thm) :: alias, fold (insert (op =)) some_class classes))

  end;

fun resubst_alias thy =

  let

    val alias = fst (ConstAlias.get thy);

    val subst_inst_param = Option.map fst o AxClass.inst_of_param thy;

    fun subst_alias c =

      get_first (fn ((c', c''), _) => if c = c'' then SOME c' else NONE) alias;

  in

    perhaps subst_inst_param

    #> perhaps subst_alias

  end;

val triv_classes = snd o ConstAlias.get;

(* reading constants as terms *)

fun check_bare_const thy t = case try dest_Const t

 of SOME c_ty => c_ty

  | NONE => error ("Not a constant: " ^ Syntax.string_of_term_global thy t);

fun check_const thy = AxClass.unoverload_const thy o check_bare_const thy;

fun read_bare_const thy = check_bare_const thy o Syntax.read_term_global thy;

fun read_const thy = AxClass.unoverload_const thy o read_bare_const thy;

(* constructor sets *)

fun constrset_of_consts thy cs =

  let

    val _ = map (fn (c, _) => if (is_some o AxClass.class_of_param thy) c

      then error ("Is a class parameter: " ^ string_of_const thy c) else ()) cs;

    fun no_constr (c, ty) = error ("Not a datatype constructor: " ^ string_of_const thy c

      ^ " :: " ^ string_of_typ thy ty);

    fun last_typ c_ty ty =

      let

        val frees = OldTerm.typ_tfrees ty;

        val (tyco, vs) = ((apsnd o map) (dest_TFree) o dest_Type o snd o strip_type) ty

          handle TYPE _ => no_constr c_ty

        val _ = if has_duplicates (eq_fst (op =)) vs then no_constr c_ty else ();

        val _ = if length frees <> length vs then no_constr c_ty else ();

      in (tyco, vs) end;

    fun ty_sorts (c, ty) =

      let

        val ty_decl = (Logic.unvarifyT o Sign.the_const_type thy) c;

        val (tyco, _) = last_typ (c, ty) ty_decl;

        val (_, vs) = last_typ (c, ty) ty;

      in ((tyco, map snd vs), (c, (map fst vs, ty))) end;

    fun add ((tyco', sorts'), c) ((tyco, sorts), cs) =

      let

        val _ = if tyco' <> tyco

          then error "Different type constructors in constructor set"

          else ();

        val sorts'' = map2 (curry (Sorts.inter_sort (Sign.classes_of thy))) sorts' sorts

      in ((tyco, sorts), c :: cs) end;

    fun inst vs' (c, (vs, ty)) =

      let

        val the_v = the o AList.lookup (op =) (vs ~~ vs');

        val ty' = map_atyps (fn TFree (v, _) => TFree (the_v v)) ty;

      in (c, (fst o strip_type) ty') end;

    val c' :: cs' = map ty_sorts cs;

    val ((tyco, sorts), cs'') = fold add cs' (apsnd single c');

    val vs = Name.names Name.context Name.aT sorts;

    val cs''' = map (inst vs) cs'';

  in (tyco, (vs, rev cs''')) end;

(* code equations *)

exception BAD_THM of string;

fun bad_thm msg = raise BAD_THM msg;

fun error_thm f thm = f thm handle BAD_THM msg => error msg;

fun warning_thm f thm = SOME (f thm) handle BAD_THM msg => (warning msg; NONE)

fun try_thm f thm = SOME (f thm) handle BAD_THM _ => NONE;

fun is_linear thm =

  let val (_, args) = (strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of) thm

  in not (has_duplicates (op =) ((fold o fold_aterms)

    (fn Var (v, _) => cons v | _ => I) args [])) end;

fun gen_assert_eqn thy is_constr_head is_constr_pat (thm, proper) =

  let

    val (lhs, rhs) = (Logic.dest_equals o Thm.plain_prop_of) thm

      handle TERM _ => bad_thm ("Not an equation: " ^ Display.string_of_thm thm)

           | THM _ => bad_thm ("Not an equation: " ^ Display.string_of_thm thm);

    fun vars_of t = fold_aterms (fn Var (v, _) => insert (op =) v

      | Free _ => bad_thm ("Illegal free variable in equation\n"

          ^ Display.string_of_thm thm)

      | _ => I) t [];

    fun tvars_of t = fold_term_types (fn _ =>

      fold_atyps (fn TVar (v, _) => insert (op =) v

        | TFree _ => bad_thm 

      ("Illegal free type variable in equation\n" ^ Display.string_of_thm thm))) t [];

    val lhs_vs = vars_of lhs;

    val rhs_vs = vars_of rhs;

    val lhs_tvs = tvars_of lhs;

    val rhs_tvs = tvars_of rhs;

    val _ = if null (subtract (op =) lhs_vs rhs_vs)

      then ()

      else bad_thm ("Free variables on right hand side of equation\n"

        ^ Display.string_of_thm thm);

    val _ = if null (subtract (op =) lhs_tvs rhs_tvs)

      then ()

      else bad_thm ("Free type variables on right hand side of equation\n"

        ^ Display.string_of_thm thm)    val (head, args) = (strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of) thm;

    val (c, ty) = case head

     of Const (c_ty as (_, ty)) => (AxClass.unoverload_const thy c_ty, ty)

      | _ => bad_thm ("Equation not headed by constant\n" ^ Display.string_of_thm thm);

    fun check _ (Abs _) = bad_thm

          ("Abstraction on left hand side of equation\n"

            ^ Display.string_of_thm thm)

      | check 0 (Var _) = ()

      | check _ (Var _) = bad_thm

          ("Variable with application on left hand side of equation\n"

            ^ Display.string_of_thm thm)

      | check n (t1 $ t2) = (check (n+1) t1; check 0 t2)

      | check n (Const (c_ty as (c, ty))) = if n = (length o fst o strip_type) ty

          then if not proper orelse is_constr_pat (AxClass.unoverload_const thy c_ty)

            then ()

            else bad_thm (quote c ^ " is not a constructor, on left hand side of equation\n"

              ^ Display.string_of_thm thm)

          else bad_thm

            ("Partially applied constant " ^ quote c ^ " on left hand side of equation\n"

               ^ Display.string_of_thm thm);

    val _ = map (check 0) args;

    val _ = if not proper orelse is_linear thm then ()

      else bad_thm ("Duplicate variables on left hand side of equation\n"

        ^ Display.string_of_thm thm);

    val _ = if (is_none o AxClass.class_of_param thy) c

      then ()

      else bad_thm ("Polymorphic constant as head in equation\n"

        ^ Display.string_of_thm thm)

    val _ = if not (is_constr_head c)

      then ()

      else bad_thm ("Constructor as head in equation\n"

        ^ Display.string_of_thm thm)

    val ty_decl = Sign.the_const_type thy c;

    val _ = if Sign.typ_equiv thy (Type.strip_sorts ty_decl, Type.strip_sorts ty)

      then () else bad_thm ("Type\n" ^ string_of_typ thy ty

           ^ "\nof equation\n"

           ^ Display.string_of_thm thm

           ^ "\nis incompatible with declared function type\n"

           ^ string_of_typ thy ty_decl)

  in (thm, proper) end;

fun assert_eqn thy is_constr = error_thm (gen_assert_eqn thy is_constr is_constr);

val const_typ_eqn = dest_Const o fst o strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of;

(*those following are permissive wrt. to overloaded constants!*)

fun mk_eqn thy is_constr_head = error_thm (gen_assert_eqn thy is_constr_head (K true)) o

  apfst (LocalDefs.meta_rewrite_rule (ProofContext.init thy));

fun mk_eqn_warning thy is_constr_head = Option.map (fn (thm, _) => (thm, is_linear thm))

  o warning_thm (gen_assert_eqn thy is_constr_head (K true))

  o rpair false o LocalDefs.meta_rewrite_rule (ProofContext.init thy);

fun mk_eqn_liberal thy is_constr_head = Option.map (fn (thm, _) => (thm, is_linear thm))

  o try_thm (gen_assert_eqn thy is_constr_head (K true))

  o rpair false o LocalDefs.meta_rewrite_rule (ProofContext.init thy);

fun const_typ_eqn_unoverload thy thm =

  let

    val (c, ty) = const_typ_eqn thm;

    val c' = AxClass.unoverload_const thy (c, ty);

  in (c', ty) end;

fun typscheme_eqn thy = typscheme thy o const_typ_eqn_unoverload thy;

fun const_eqn thy = fst o const_typ_eqn_unoverload thy;

(* case cerificates *)

fun case_certificate thm =

  let

    val ((head, raw_case_expr), cases) = (apfst Logic.dest_equals

      o apsnd Logic.dest_conjunctions o Logic.dest_implies o Thm.prop_of) thm;

    val _ = case head of Free _ => true

      | Var _ => true

      | _ => raise TERM ("case_cert", []);

    val ([(case_var, _)], case_expr) = Term.strip_abs_eta 1 raw_case_expr;

    val (Const (case_const, _), raw_params) = strip_comb case_expr;

    val n = find_index (fn Free (v, _) => v = case_var | _ => false) raw_params;

    val _ = if n = ~1 then raise TERM ("case_cert", []) else ();

    val params = map (fst o dest_Var) (nth_drop n raw_params);

    fun dest_case t =

      let

        val (head' $ t_co, rhs) = Logic.dest_equals t;

        val _ = if head' = head then () else raise TERM ("case_cert", []);

        val (Const (co, _), args) = strip_comb t_co;

        val (Var (param, _), args') = strip_comb rhs;

        val _ = if args' = args then () else raise TERM ("case_cert", []);

      in (param, co) end;

    fun analyze_cases cases =

      let

        val co_list = fold (AList.update (op =) o dest_case) cases [];

      in map (the o AList.lookup (op =) co_list) params end;

    fun analyze_let t =

      let

        val (head' $ arg, Var (param', _) $ arg') = Logic.dest_equals t;

        val _ = if head' = head then () else raise TERM ("case_cert", []);

        val _ = if arg' = arg then () else raise TERM ("case_cert", []);

        val _ = if [param'] = params then () else raise TERM ("case_cert", []);

      in [] end;

    fun analyze (cases as [let_case]) =

          (analyze_cases cases handle Bind => analyze_let let_case)

      | analyze cases = analyze_cases cases;

  in (case_const, (n, analyze cases)) end;

fun case_cert thm = case_certificate thm

  handle Bind => error "bad case certificate"

       | TERM _ => error "bad case certificate";

(** code attributes **)

structure CodeAttr = TheoryDataFun (

  type T = (string * attribute parser) list;

  val empty = [];

  val copy = I;

  val extend = I;

  fun merge _ = AList.merge (op = : string * string -> bool) (K true);

);

fun add_attribute (attr as (name, _)) =

  let

    fun add_parser ("", parser) attrs = attrs |> rev |> AList.update (op =) ("", parser) |> rev

      | add_parser (name, parser) attrs = (name, Args.$$$ name |-- parser) :: attrs;

  in CodeAttr.map (fn attrs => if not (name = "") andalso AList.defined (op =) attrs name

    then error ("Code attribute " ^ name ^ " already declared") else add_parser attr attrs)

  end;

val _ = Context.>> (Context.map_theory

  (Attrib.setup (Binding.name "code")

    (Scan.peek (fn context =>

      List.foldr op || Scan.fail (map snd (CodeAttr.get (Context.theory_of context)))))

    "declare theorems for code generation"));

(** logical and syntactical specification of executable code **)

(* code equations *)

type eqns = bool * (thm * bool) list lazy;

  (*default flag, theorems with proper flag (perhaps lazy)*)

fun pretty_lthms ctxt r = case Lazy.peek r

 of SOME thms => map (ProofContext.pretty_thm ctxt o fst) (Exn.release thms)

  | NONE => [Pretty.str "[...]"];

fun certificate thy f r =

  case Lazy.peek r

   of SOME thms => (Lazy.value o f thy) (Exn.release thms)

    | NONE => let

        val thy_ref = Theory.check_thy thy;

      in Lazy.lazy (fn () => (f (Theory.deref thy_ref) o Lazy.force) r) end;

fun add_drop_redundant thy (thm, proper) thms =

  let

    val args_of = snd o strip_comb o map_types Type.strip_sorts

      o fst o Logic.dest_equals o Thm.plain_prop_of;

    val args = args_of thm;

    val incr_idx = Logic.incr_indexes ([], Thm.maxidx_of thm + 1);

    fun matches_args args' = length args <= length args' andalso

      Pattern.matchess thy (args, (map incr_idx o curry Library.take (length args)) args');

    fun drop (thm', proper') = if (proper orelse not proper')

      andalso matches_args (args_of thm') then 

        (warning ("Code generator: dropping redundant code equation\n" ^ Display.string_of_thm thm'); true)

      else false;

  in (thm, proper) :: filter_out drop thms end;

fun add_thm thy _ thm (false, thms) = (false, Lazy.map_force (add_drop_redundant thy thm) thms)

  | add_thm thy true thm (true, thms) = (true, Lazy.map_force (fn thms => thms @ [thm]) thms)

  | add_thm thy false thm (true, thms) = (false, Lazy.value [thm]);

fun add_lthms lthms _ = (false, lthms);

fun del_thm thm = (apsnd o Lazy.map_force) (remove (eq_fst Thm.eq_thm_prop) (thm, true));

(* specification data *)

datatype spec = Spec of {

  concluded_history: bool,

  eqns: ((bool * eqns) * (serial * eqns) list) Symtab.table

    (*with explicit history*),

  dtyps: ((serial * ((string * sort) list * (string * typ list) list)) list) Symtab.table

    (*with explicit history*),

  cases: (int * (int * string list)) Symtab.table * unit Symtab.table

};

fun make_spec ((concluded_history, eqns), (dtyps, cases)) =

  Spec { concluded_history = concluded_history, eqns = eqns, dtyps = dtyps, cases = cases };

fun map_spec f (Spec { concluded_history = concluded_history, eqns = eqns,

  dtyps = dtyps, cases = cases }) =

  make_spec (f ((concluded_history, eqns), (dtyps, cases)));

fun merge_spec (Spec { concluded_history = _, eqns = eqns1, dtyps = dtyps1, cases = (cases1, undefs1) },

  Spec { concluded_history = _, eqns = eqns2, dtyps = dtyps2, cases = (cases2, undefs2) }) =

  let

    fun merge_eqns ((_, history1), (_, history2)) =

      let

        val raw_history = AList.merge (op = : serial * serial -> bool)

          (K true) (history1, history2)

        val filtered_history = filter_out (fst o snd) raw_history

        val history = if null filtered_history

          then raw_history else filtered_history;

      in ((false, (snd o hd) history), history) end;

    val eqns = Symtab.join (K merge_eqns) (eqns1, eqns2);

    val dtyps = Symtab.join (K (AList.merge (op =) (K true))) (dtyps1, dtyps2);

    val cases = (Symtab.merge (K true) (cases1, cases2),

      Symtab.merge (K true) (undefs1, undefs2));

  in make_spec ((false, eqns), (dtyps, cases)) end;

(* code setup data *)

fun the_spec (Spec x) = x;

fun the_eqns (Spec { eqns, ... }) = eqns;

fun the_dtyps (Spec { dtyps, ... }) = dtyps;

fun the_cases (Spec { cases, ... }) = cases;

fun history_concluded (Spec { concluded_history, ... }) = concluded_history;

val map_concluded_history = map_spec o apfst o apfst;

val map_eqns = map_spec o apfst o apsnd;

val map_dtyps = map_spec o apsnd o apfst;

val map_cases = map_spec o apsnd o apsnd;

(* data slots dependent on executable content *)

(*private copy avoids potential conflict of table exceptions*)

structure Datatab = TableFun(type key = int val ord = int_ord);

local

type kind = {

  empty: Object.T,

  purge: theory -> string list -> Object.T -> Object.T

};

val kinds = ref (Datatab.empty: kind Datatab.table);

val kind_keys = ref ([]: serial list);

fun invoke f k = case Datatab.lookup (! kinds) k

 of SOME kind => f kind

  | NONE => sys_error "Invalid code data identifier";

in

fun declare_data empty purge =

  let

    val k = serial ();

    val kind = {empty = empty, purge = purge};

    val _ = change kinds (Datatab.update (k, kind));

    val _ = change kind_keys (cons k);

  in k end;

fun invoke_init k = invoke (fn kind => #empty kind) k;

fun invoke_purge_all thy cs =

  fold (fn k => Datatab.map_entry k

    (invoke (fn kind => #purge kind thy cs) k)) (! kind_keys);

end; (*local*)

(** theory store **)

local

type data = Object.T Datatab.table;

val empty_data = Datatab.empty : data;

structure Code_Data = TheoryDataFun

(

  type T = spec * data ref;

  val empty = (make_spec ((false, Symtab.empty),

    (Symtab.empty, (Symtab.empty, Symtab.empty))), ref empty_data);

  fun copy (spec, data) = (spec, ref (! data));

  val extend = copy;

  fun merge pp ((spec1, data1), (spec2, data2)) =

    (merge_spec (spec1, spec2), ref empty_data);

);

fun thy_data f thy = f ((snd o Code_Data.get) thy);

fun get_ensure_init kind data_ref =

  case Datatab.lookup (! data_ref) kind

   of SOME x => x

    | NONE => let val y = invoke_init kind

        in (change data_ref (Datatab.update (kind, y)); y) end;

in

(* access to executable content *)

val the_exec = fst o Code_Data.get;

fun complete_class_params thy cs =

  fold (fn c => case AxClass.inst_of_param thy c

   of NONE => insert (op =) c

    | SOME (c', _) => insert (op =) c' #> insert (op =) c) cs [];

fun map_exec_purge touched f thy =

  Code_Data.map (fn (exec, data) => (f exec, ref (case touched

   of SOME cs => invoke_purge_all thy (complete_class_params thy cs) (! data)

    | NONE => empty_data))) thy;

val purge_data = (Code_Data.map o apsnd) (K (ref empty_data));

(* tackling equation history *)

fun get_eqns thy c =

  Symtab.lookup ((the_eqns o the_exec) thy) c

  |> Option.map (Lazy.force o snd o snd o fst)

  |> these;

fun continue_history thy = if (history_concluded o the_exec) thy

  then thy

    |> (Code_Data.map o apfst o map_concluded_history) (K false)

    |> SOME

  else NONE;

fun conclude_history thy = if (history_concluded o the_exec) thy

  then NONE

  else thy

    |> (Code_Data.map o apfst)

        ((map_eqns o Symtab.map) (fn ((changed, current), history) =>

          ((false, current),

            if changed then (serial (), current) :: history else history))

        #> map_concluded_history (K true))

    |> SOME;

val _ = Context.>> (Context.map_theory (Code_Data.init

  #> Theory.at_begin continue_history

  #> Theory.at_end conclude_history));

(* access to data dependent on abstract executable content *)

fun get_data (kind, _, dest) = thy_data (get_ensure_init kind #> dest);

fun change_data (kind, mk, dest) =

  let

    fun chnge data_ref f =

      let

        val data = get_ensure_init kind data_ref;

        val data' = f (dest data);

      in (change data_ref (Datatab.update (kind, mk data')); data') end;

  in thy_data chnge end;

fun change_yield_data (kind, mk, dest) =

  let

    fun chnge data_ref f =

      let

        val data = get_ensure_init kind data_ref;

        val (x, data') = f (dest data);

      in (x, (change data_ref (Datatab.update (kind, mk data')); data')) end;

  in thy_data chnge end;

end; (*local*)

fun print_codesetup thy =

  let

    val ctxt = ProofContext.init thy;

    val exec = the_exec thy;

    fun pretty_eqn (s, (_, lthms)) =

      (Pretty.block o Pretty.fbreaks) (

        Pretty.str s :: pretty_lthms ctxt lthms

      );

    fun pretty_dtyp (s, []) =

          Pretty.str s

      | pretty_dtyp (s, cos) =

          (Pretty.block o Pretty.breaks) (

            Pretty.str s

            :: Pretty.str "="

            :: separate (Pretty.str "|") (map (fn (c, []) => Pretty.str (string_of_const thy c)

                 | (c, tys) =>

                     (Pretty.block o Pretty.breaks)

                        (Pretty.str (string_of_const thy c)

                          :: Pretty.str "of"

                          :: map (Pretty.quote o Syntax.pretty_typ_global thy) tys)) cos)

          );

    val eqns = the_eqns exec

      |> Symtab.dest

      |> (map o apfst) (string_of_const thy)

      |> (map o apsnd) (snd o fst)

      |> sort (string_ord o pairself fst);

    val dtyps = the_dtyps exec

      |> Symtab.dest

      |> map (fn (dtco, (_, (vs, cos)) :: _) =>

          (Syntax.string_of_typ_global thy (Type (dtco, map TFree vs)), cos))

      |> sort (string_ord o pairself fst)

  in

    (Pretty.writeln o Pretty.chunks) [

      Pretty.block (

        Pretty.str "code equations:"

        :: Pretty.fbrk

        :: (Pretty.fbreaks o map pretty_eqn) eqns

      ),

      Pretty.block (

        Pretty.str "datatypes:"

        :: Pretty.fbrk

        :: (Pretty.fbreaks o map pretty_dtyp) dtyps

      )

    ]

  end;

(** theorem transformation and certification **)

fun common_typ_eqns thy [] = []

  | common_typ_eqns thy [thm] = [thm]

  | common_typ_eqns thy (thms as thm :: _) = (*FIXME is too general*)

      let

        fun incr_thm thm max =

          let

            val thm' = incr_indexes max thm;

            val max' = Thm.maxidx_of thm' + 1;

          in (thm', max') end;

        val (thms', maxidx) = fold_map incr_thm thms 0;

        val ty1 :: tys = map (snd o const_typ_eqn) thms';

        fun unify ty env = Sign.typ_unify thy (ty1, ty) env

          handle Type.TUNIFY =>

            error ("Type unificaton failed, while unifying code equations\n"

            ^ (cat_lines o map Display.string_of_thm) thms

            ^ "\nwith types\n"

            ^ (cat_lines o map (string_of_typ thy)) (ty1 :: tys));

        val (env, _) = fold unify tys (Vartab.empty, maxidx)

        val instT = Vartab.fold (fn (x_i, (sort, ty)) =>

          cons (Thm.ctyp_of thy (TVar (x_i, sort)), Thm.ctyp_of thy ty)) env [];

      in map (Thm.instantiate (instT, [])) thms' end;

(** interfaces and attributes **)

fun get_datatype thy tyco =

  case these (Symtab.lookup ((the_dtyps o the_exec) thy) tyco)

   of (_, spec) :: _ => spec

    | [] => Sign.arity_number thy tyco

        |> Name.invents Name.context Name.aT

        |> map (rpair [])

        |> rpair [];

fun get_datatype_of_constr thy c =

  case (snd o strip_type o Sign.the_const_type thy) c

   of Type (tyco, _) => if member (op =) ((map fst o snd o get_datatype thy) tyco) c

       then SOME tyco else NONE

    | _ => NONE;

fun is_constr thy = is_some o get_datatype_of_constr thy;

val assert_eqn = fn thy => assert_eqn thy (is_constr thy);

fun assert_eqns_const thy c eqns =

  let

    fun cert (eqn as (thm, _)) = if c = const_eqn thy thm

      then eqn else error ("Wrong head of code equation,\nexpected constant "

        ^ string_of_const thy c ^ "\n" ^ Display.string_of_thm thm)

  in map (cert o assert_eqn thy) eqns end;

fun change_eqns delete c f = (map_exec_purge (SOME [c]) o map_eqns

  o (if delete then Symtab.map_entry c else Symtab.map_default (c, ((false, (true, Lazy.value [])), [])))

    o apfst) (fn (_, eqns) => (true, f eqns));

fun gen_add_eqn default (eqn as (thm, _)) thy =

  let val c = const_eqn thy thm

  in change_eqns false c (add_thm thy default eqn) thy end;

fun add_eqn thm thy =

  gen_add_eqn false (mk_eqn thy (is_constr thy) (thm, true)) thy;

fun add_warning_eqn thm thy =

  case mk_eqn_warning thy (is_constr thy) thm

   of SOME eqn => gen_add_eqn false eqn thy

    | NONE => thy;

fun add_default_eqn thm thy =

  case mk_eqn_liberal thy (is_constr thy) thm

   of SOME eqn => gen_add_eqn true eqn thy

    | NONE => thy;

fun add_nbe_eqn thm thy =

  gen_add_eqn false (mk_eqn thy (is_constr thy) (thm, false)) thy;

fun add_eqnl (c, lthms) thy =

  let

    val lthms' = certificate thy (fn thy => assert_eqns_const thy c) lthms;

  in change_eqns false c (add_lthms lthms') thy end;

val add_default_eqn_attribute = Thm.declaration_attribute

  (fn thm => Context.mapping (add_default_eqn thm) I);

val add_default_eqn_attrib = Attrib.internal (K add_default_eqn_attribute);

fun del_eqn thm thy = case mk_eqn_liberal thy (is_constr thy) thm

 of SOME (thm, _) => change_eqns true (const_eqn thy thm) (del_thm thm) thy

  | NONE => thy;

fun del_eqns c = change_eqns true c (K (false, Lazy.value []));

fun get_case_scheme thy = Symtab.lookup ((fst o the_cases o the_exec) thy);

val is_undefined = Symtab.defined o snd o the_cases o the_exec;

structure TypeInterpretation = InterpretationFun(type T = string * serial val eq = eq_snd (op =) : T * T -> bool);

fun add_datatype raw_cs thy =

  let

    val cs = map (fn c_ty as (_, ty) => (AxClass.unoverload_const thy c_ty, ty)) raw_cs;

    val (tyco, vs_cos) = constrset_of_consts thy cs;

    val old_cs = (map fst o snd o get_datatype thy) tyco;

    fun drop_outdated_cases cases = fold Symtab.delete_safe

      (Symtab.fold (fn (c, (_, (_, cos))) =>

        if exists (member (op =) old_cs) cos

          then insert (op =) c else I) cases []) cases;

  in

    thy

    |> fold (del_eqns o fst) cs

    |> map_exec_purge NONE

        ((map_dtyps o Symtab.map_default (tyco, [])) (cons (serial (), vs_cos))

        #> (map_cases o apfst) drop_outdated_cases)

    |> TypeInterpretation.data (tyco, serial ())

  end;

fun type_interpretation f =  TypeInterpretation.interpretation

  (fn (tyco, _) => fn thy => f (tyco, get_datatype thy tyco) thy);

fun add_datatype_cmd raw_cs thy =

  let

    val cs = map (read_bare_const thy) raw_cs;

  in add_datatype cs thy end;

fun add_case thm thy =

  let

    val (c, (k, case_pats)) = case_cert thm;

    val _ = case filter_out (is_constr thy) case_pats

     of [] => ()

      | cs => error ("Non-constructor(s) in case certificate: " ^ commas (map quote cs));

    val entry = (1 + Int.max (1, length case_pats), (k, case_pats))

  in (map_exec_purge (SOME [c]) o map_cases o apfst) (Symtab.update (c, entry)) thy end;

fun add_undefined c thy =

  (map_exec_purge (SOME [c]) o map_cases o apsnd) (Symtab.update (c, ())) thy;

val _ = Context.>> (Context.map_theory

  (let

    fun mk_attribute f = Thm.declaration_attribute (fn thm => Context.mapping (f thm) I);

    fun add_simple_attribute (name, f) =

      add_attribute (name, Scan.succeed (mk_attribute f));

    fun add_del_attribute (name, (add, del)) =

      add_attribute (name, Args.del |-- Scan.succeed (mk_attribute del)

        || Scan.succeed (mk_attribute add))

  in

    TypeInterpretation.init

    #> add_del_attribute ("", (add_warning_eqn, del_eqn))

    #> add_simple_attribute ("nbe", add_nbe_eqn)

  end));

fun these_eqns thy c =

  get_eqns thy c

  |> (map o apfst) (Thm.transfer thy)

  |> burrow_fst (common_typ_eqns thy);

fun all_eqns thy =

  Symtab.dest ((the_eqns o the_exec) thy)

  |> maps (Lazy.force o snd o snd o fst o snd);

fun default_typscheme thy c =

  let

    fun the_const_typscheme c = (curry (typscheme thy) c o snd o dest_Const

      o TermSubst.zero_var_indexes o curry Const "" o Sign.the_const_type thy) c;

    fun strip_sorts (vs, ty) = (map (fn (v, _) => (v, [])) vs, ty);

  in case AxClass.class_of_param thy c

   of SOME class => ([(Name.aT, [class])], snd (the_const_typscheme c))

    | NONE => if is_constr thy c

        then strip_sorts (the_const_typscheme c)

        else case get_eqns thy c

         of (thm, _) :: _ => (typscheme_eqn thy o Drule.zero_var_indexes) thm

          | [] => strip_sorts (the_const_typscheme c) end;

end; (*struct*)

(** type-safe interfaces for data depedent on executable content **)

functor CodeDataFun(Data: CODE_DATA_ARGS): CODE_DATA =

struct

type T = Data.T;

exception Data of T;

fun dest (Data x) = x

val kind = Code.declare_data (Data Data.empty)

  (fn thy => fn cs => fn Data x => Data (Data.purge thy cs x));