(*  Title:      Pure/Tools/codegen_package.ML

    ID:         $Id$

    Author:     Florian Haftmann, TU Muenchen

Code generator extraction kernel. Code generator Isar setup.

*)

signature CODEGEN_PACKAGE =

sig

  include BASIC_CODEGEN_THINGOL;

  val codegen_term: theory -> term -> thm * iterm;

  val eval_term: theory -> (string (*reference name!*) * 'a option ref) * term -> 'a;

  val const_of_idf: theory -> string -> string * typ;

  val get_root_module: theory -> CodegenThingol.code;

  type appgen;

  val add_appconst: string * appgen -> theory -> theory;

  val appgen_numeral: (theory -> term -> IntInf.int) -> appgen;

  val appgen_char: (term -> int option) -> appgen;

  val appgen_case: (theory -> term

    -> ((string * typ) list * ((term * typ) * (term * term) list)) option)

    -> appgen;

  val appgen_let: appgen;

end;

structure CodegenPackage : CODEGEN_PACKAGE =

struct

open BasicCodegenThingol;

val tracing = CodegenThingol.tracing;

val succeed = CodegenThingol.succeed;

val fail = CodegenThingol.fail;

(** code extraction **)

(* theory data *)

structure Code = CodeDataFun

(struct

  val name = "Pure/code";

  type T = CodegenThingol.code;

  val empty = CodegenThingol.empty_code;

  fun merge _ = CodegenThingol.merge_code;

  fun purge _ NONE _ = CodegenThingol.empty_code

    | purge NONE _ _ = CodegenThingol.empty_code

    | purge (SOME thy) (SOME cs) code =

        let

          val cs_exisiting =

            map_filter (CodegenNames.const_rev thy) (Graph.keys code);

        in

          Graph.del_nodes

            ((Graph.all_succs code

              o map (CodegenNames.const thy)

              o filter (member CodegenConsts.eq_const cs_exisiting)

              ) cs)

            code

        end;

end);

type appgen = theory -> ((sort -> sort) * Sorts.algebra) * Consts.T

  -> CodegenFuncgr.T

  -> bool * string list option

  -> (string * typ) * term list -> CodegenThingol.transact -> iterm * CodegenThingol.transact;

type appgens = (int * (appgen * stamp)) Symtab.table;

val merge_appgens : appgens * appgens -> appgens =

  Symtab.merge (fn ((bounds1, (_, stamp1)), (bounds2, (_, stamp2))) =>

    bounds1 = bounds2 andalso stamp1 = stamp2);

structure Consttab = CodegenConsts.Consttab;

type abstypes = typ Symtab.table * CodegenConsts.const Consttab.table;

fun merge_abstypes ((typs1, consts1) : abstypes, (typs2, consts2) : abstypes) =

  (Symtab.merge (Type.eq_type Vartab.empty) (typs1, typs2),

    Consttab.merge CodegenConsts.eq_const (consts1, consts2));

structure CodegenPackageData = TheoryDataFun

(struct

  val name = "Pure/codegen_package";

  type T = appgens * abstypes;

  val empty = (Symtab.empty, (Symtab.empty, Consttab.empty));

  val copy = I;

  val extend = I;

  fun merge _ ((appgens1, abstypes1), (appgens2, abstypes2)) =

    (merge_appgens (appgens1, appgens2), merge_abstypes (abstypes1, abstypes2));

  fun print _ _ = ();

end);

val _ = Context.add_setup (Code.init #> CodegenPackageData.init);

(* extraction kernel *)

fun check_strict (false, _) has_seri x =

      false

  | check_strict (_, SOME targets) has_seri x =

      not (has_seri targets x)

  | check_strict (true, _) has_seri x =

      true;

fun get_abstype thy (tyco, tys) = case Symtab.lookup ((fst o snd o CodegenPackageData.get) thy) tyco

 of SOME ty => SOME ((map_atyps (fn TFree (n, _) => nth tys (the (Int.fromString n)))) ty)

  | NONE => NONE;

fun ensure_def_class thy (algbr as ((proj_sort, _), _)) funcgr strct class trns =

  let

    val (v, cs) = (ClassPackage.the_consts_sign thy) class;

    val superclasses = (proj_sort o Sign.super_classes thy) class;

    val classops' = map (CodegenNames.const thy o CodegenConsts.norm_of_typ thy) cs;

    val class' = CodegenNames.class thy class;

    fun defgen_class trns =

      trns

      |> fold_map (ensure_def_class thy algbr funcgr strct) superclasses

      ||>> (fold_map (exprgen_type thy algbr funcgr strct) o map snd) cs

      |-> (fn (superclasses, classoptyps) => succeed

        (CodegenThingol.Class (superclasses,

          (unprefix "'" v, classops' ~~ classoptyps))))

  in

    trns

    |> tracing (fn _ => "generating class " ^ quote class)

    |> CodegenThingol.ensure_def defgen_class true

        ("generating class " ^ quote class) class'

    |> pair class'

  end

and ensure_def_tyco thy algbr funcgr strct tyco trns =

  let

    fun defgen_datatype trns =

      case CodegenData.get_datatype thy tyco

       of SOME (vs, cos) =>

            trns

            |> fold_map (exprgen_tyvar_sort thy algbr funcgr strct) vs

            ||>> fold_map (fn (c, tys) =>

              fold_map (exprgen_type thy algbr funcgr strct) tys

              #-> (fn tys' =>

                pair ((CodegenNames.const thy o CodegenConsts.norm_of_typ thy)

                  (c, tys ---> Type (tyco, map TFree vs)), tys'))) cos

            |-> (fn (vs, cos) => succeed (CodegenThingol.Datatype (vs, cos)))

        | NONE =>

            trns

            |> fail ("No such datatype: " ^ quote tyco)

    val tyco' = CodegenNames.tyco thy tyco;

    val strict = check_strict strct (CodegenSerializer.tyco_has_serialization thy) tyco';

  in

    trns

    |> tracing (fn _ => "generating type constructor " ^ quote tyco)

    |> CodegenThingol.ensure_def defgen_datatype strict

        ("generating type constructor " ^ quote tyco) tyco'

    |> pair tyco'

  end

and exprgen_tyvar_sort thy (algbr as ((proj_sort, _), _)) funcgr strct (v, sort) trns =

  trns

  |> fold_map (ensure_def_class thy algbr funcgr strct) (proj_sort sort)

  |-> (fn sort => pair (unprefix "'" v, sort))

and exprgen_type thy algbr funcgr strct (TVar _) trns =

      error "TVar encountered in typ during code generation"

  | exprgen_type thy algbr funcgr strct (TFree vs) trns =

      trns

      |> exprgen_tyvar_sort thy algbr funcgr strct vs

      |-> (fn (v, sort) => pair (ITyVar v))

  | exprgen_type thy algbr funcgr strct (Type ("fun", [t1, t2])) trns =

      trns

      |> exprgen_type thy algbr funcgr strct t1

      ||>> exprgen_type thy algbr funcgr strct t2

      |-> (fn (t1', t2') => pair (t1' `-> t2'))

  | exprgen_type thy algbr funcgr strct (Type (tyco, tys)) trns =

      case get_abstype thy (tyco, tys)

       of SOME ty =>

            trns

            |> exprgen_type thy algbr funcgr strct ty

        | NONE =>

            trns

            |> ensure_def_tyco thy algbr funcgr strct tyco

            ||>> fold_map (exprgen_type thy algbr funcgr strct) tys

            |-> (fn (tyco, tys) => pair (tyco `%% tys));

exception CONSTRAIN of (string * typ) * typ;

fun exprgen_typinst thy (algbr as ((proj_sort, algebra), consts)) funcgr strct (ty_ctxt, sort_decl) trns =

  let

    val pp = Sign.pp thy;

    datatype inst =

        Inst of (class * string) * inst list list

      | Contxt of (string * sort) * (class list * int);

    fun classrel (l as Contxt (v_sort, (classes, n)), _) class  =

          Contxt (v_sort, (class :: classes, n))

      | classrel (Inst ((_, tyco), lss), _) class =

          Inst ((class, tyco), lss);

    fun constructor tyco iss class =

      Inst ((class, tyco), (map o map) fst iss);

    fun variable (TFree (v, sort)) =

      let

        val sort' = proj_sort sort;

      in map_index (fn (n, class) => (Contxt ((v, sort'), ([], n)), class)) sort' end;

    val insts = Sorts.of_sort_derivation pp algebra

      {classrel = classrel, constructor = constructor, variable = variable}

      (ty_ctxt, proj_sort sort_decl);

    fun mk_dict (Inst (inst, instss)) trns =

          trns

          |> ensure_def_inst thy algbr funcgr strct inst

          ||>> (fold_map o fold_map) mk_dict instss

          |-> (fn (inst, instss) => pair (Instance (inst, instss)))

      | mk_dict (Contxt ((v, sort), (classes, k))) trns =

          trns

          |> fold_map (ensure_def_class thy algbr funcgr strct) classes

          |-> (fn classes => pair (Context (classes, (unprefix "'" v,

                if length sort = 1 then ~1 else k))))

  in

    trns

    |> fold_map mk_dict insts

  end

and exprgen_typinst_const thy (algbr as (_, consts)) funcgr strct (c, ty_ctxt) trns =

  let

    val c' = CodegenConsts.norm_of_typ thy (c, ty_ctxt)

    val idf = CodegenNames.const thy c';

    val ty_decl = Consts.declaration consts idf;

    val insts = (op ~~ o apsnd (map (snd o dest_TVar)) oo pairself)

      (curry (Consts.typargs consts) idf) (ty_ctxt, ty_decl);

    val _ = if exists not (map (Sign.of_sort thy) insts)

      then raise CONSTRAIN ((c, ty_decl), ty_ctxt) else ();

  in

    trns

    |> fold_map (exprgen_typinst thy algbr funcgr strct) insts

  end

and ensure_def_inst thy (algbr as ((proj_sort, _), _)) funcgr strct (class, tyco) trns =

  let

    val (vs, classop_defs) = ((apsnd o map) Const o ClassPackage.the_inst_sign thy)

      (class, tyco);

    val classops = (map (CodegenConsts.norm_of_typ thy) o snd

      o ClassPackage.the_consts_sign thy) class;

    val arity_typ = Type (tyco, (map TFree vs));

    val superclasses = (proj_sort o Sign.super_classes thy) class

    fun gen_superarity superclass trns =

      trns

      |> ensure_def_class thy algbr funcgr strct superclass

      ||>> exprgen_typinst thy algbr funcgr strct (arity_typ, [superclass])

      |-> (fn (superclass, [Instance (inst, iss)]) => pair (superclass, (inst, iss)));

    fun gen_classop_def (classop, t) trns =

      trns

      |> ensure_def_const thy algbr funcgr strct classop

      ||>> exprgen_term thy algbr funcgr strct t;

    fun defgen_inst trns =

      trns

      |> ensure_def_class thy algbr funcgr strct class

      ||>> ensure_def_tyco thy algbr funcgr strct tyco

      ||>> fold_map (exprgen_tyvar_sort thy algbr funcgr strct) vs

      ||>> fold_map gen_superarity superclasses

      ||>> fold_map gen_classop_def (classops ~~ classop_defs)

      |-> (fn ((((class, tyco), arity), superarities), classops) =>

             succeed (CodegenThingol.Classinst ((class, (tyco, arity)), (superarities, classops))));

    val inst = CodegenNames.instance thy (class, tyco);

  in

    trns

    |> tracing (fn _ => "generating instance " ^ quote class ^ " / " ^ quote tyco)

    |> CodegenThingol.ensure_def defgen_inst true

         ("generating instance " ^ quote class ^ " / " ^ quote tyco) inst

    |> pair inst

  end

and ensure_def_const thy (algbr as (_, consts)) funcgr strct (c, tys) trns =

  let

    val c' = CodegenNames.const thy (c, tys);

    fun defgen_datatypecons trns =

      trns

      |> ensure_def_tyco thy algbr funcgr strct

          ((the o CodegenData.get_datatype_of_constr thy) (c, tys))

      |-> (fn _ => succeed CodegenThingol.Bot);

    fun defgen_classop trns =

      trns

      |> ensure_def_class thy algbr funcgr strct ((the o AxClass.class_of_param thy) c)

      |-> (fn _ => succeed CodegenThingol.Bot);

    fun defgen_fun trns =

      case CodegenFuncgr.get_funcs funcgr

        (perhaps (Consttab.lookup ((snd o snd o CodegenPackageData.get) thy)) (c, tys))

       of eq_thms as eq_thm :: _ =>

            let

              val msg = cat_lines ("generating code for theorems " :: map string_of_thm eq_thms);

              val ty = (Logic.unvarifyT o CodegenData.typ_func thy) eq_thm;

              val vs = (map dest_TFree o Consts.typargs consts) (c', ty);

              val dest_eqthm =

                apfst (snd o strip_comb) o Logic.dest_equals o Logic.unvarify o prop_of;

              fun exprgen_eq (args, rhs) trns =

                trns

                |> fold_map (exprgen_term thy algbr funcgr strct) args

                ||>> exprgen_term thy algbr funcgr strct rhs;

            in

              trns

              |> CodegenThingol.message msg (fn trns => trns

              |> fold_map (exprgen_eq o dest_eqthm) eq_thms

              ||>> fold_map (exprgen_tyvar_sort thy algbr funcgr strct) vs

              ||>> exprgen_type thy algbr funcgr strct ty

              |-> (fn ((eqs, vs), ty) => succeed (CodegenThingol.Fun (eqs, (vs, ty)))))

            end

        | [] =>

              trns

              |> fail ("No defining equations found for "

                   ^ (quote o CodegenConsts.string_of_const thy) (c, tys));

    val defgen =

      if CodegenNames.has_nsp CodegenNames.nsp_fun c'

      then defgen_fun

      else if CodegenNames.has_nsp CodegenNames.nsp_classop c'

      then defgen_classop

      else if CodegenNames.has_nsp CodegenNames.nsp_dtco c'

      then defgen_datatypecons

      else error ("Illegal shallow name space for constant: " ^ quote c');

    val strict = check_strict strct (CodegenSerializer.const_has_serialization thy) c';

  in

    trns

    |> tracing (fn _ => "generating constant "

        ^ (quote o CodegenConsts.string_of_const thy) (c, tys))

    |> CodegenThingol.ensure_def defgen strict ("generating constant "

         ^ CodegenConsts.string_of_const thy (c, tys)) c'

    |> pair c'

  end

and exprgen_term thy algbr funcgr strct (Const (c, ty)) trns =

      trns

      |> select_appgen thy algbr funcgr strct ((c, ty), [])

  | exprgen_term thy algbr funcgr strct (Var _) trns =

      error "Var encountered in term during code generation"

  | exprgen_term thy algbr funcgr strct (Free (v, ty)) trns =

      trns

      |> exprgen_type thy algbr funcgr strct ty

      |-> (fn _ => pair (IVar v))

  | exprgen_term thy algbr funcgr strct (Abs (raw_v, ty, raw_t)) trns =

      let

        val (v, t) = Syntax.variant_abs (CodegenNames.purify_var raw_v, ty, raw_t);

      in

        trns

        |> exprgen_type thy algbr funcgr strct ty

        ||>> exprgen_term thy algbr funcgr strct t

        |-> (fn (ty, t) => pair ((v, ty) `|-> t))

      end

  | exprgen_term thy algbr funcgr strct (t as _ $ _) trns =

      case strip_comb t

       of (Const (c, ty), ts) =>

            trns

            |> select_appgen thy algbr funcgr strct ((c, ty), ts)

            |-> (fn t => pair t)

        | (t', ts) =>

            trns

            |> exprgen_term thy algbr funcgr strct t'

            ||>> fold_map (exprgen_term thy algbr funcgr strct) ts

            |-> (fn (t, ts) => pair (t `$$ ts))

and appgen_default thy algbr funcgr strct ((c, ty), ts) trns =

  trns

  |> ensure_def_const thy algbr funcgr strct (CodegenConsts.norm_of_typ thy (c, ty))

  ||>> exprgen_type thy algbr funcgr strct ty

  ||>> exprgen_typinst_const thy algbr funcgr strct (c, ty)

  ||>> fold_map (exprgen_term thy algbr funcgr strct) ts

  |-> (fn (((c, ty), iss), ts) =>

         pair (IConst (c, (iss, ty)) `$$ ts))

and select_appgen thy algbr funcgr strct ((c, ty), ts) trns =

  case Symtab.lookup (fst (CodegenPackageData.get thy)) c

   of SOME (i, (appgen, _)) =>

        if length ts < i then

          let

            val tys = Library.take (i - length ts, ((fst o strip_type) ty));

            val vs = Name.names (Name.declare c Name.context) "a" tys;

          in

            trns

            |> fold_map (exprgen_type thy algbr funcgr strct) tys

            ||>> appgen thy algbr funcgr strct ((c, ty), ts @ map Free vs)

            |-> (fn (tys, t) => pair (map2 (fn (v, _) => pair v) vs tys `|--> t))

          end

        else if length ts > i then

          trns

          |> appgen thy algbr funcgr strct ((c, ty), Library.take (i, ts))

          ||>> fold_map (exprgen_term thy algbr funcgr strct) (Library.drop (i, ts))

          |-> (fn (t, ts) => pair (t `$$ ts))

        else

          trns

          |> appgen thy algbr funcgr strct ((c, ty), ts)

    | NONE =>

        trns

        |> appgen_default thy algbr funcgr strct ((c, ty), ts);

(* entrance points into extraction kernel *)

fun ensure_def_const' thy algbr funcgr strct c trns =

  ensure_def_const thy algbr funcgr strct c trns

  handle CONSTRAIN ((c, ty), ty_decl) => error (

    "Constant " ^ c ^ " with most general type\n"

    ^ Sign.string_of_typ thy ty

    ^ "\noccurs with type\n"

    ^ Sign.string_of_typ thy ty_decl);

fun exprgen_term' thy algbr funcgr strct t trns =

  exprgen_term thy algbr funcgr strct t trns

  handle CONSTRAIN ((c, ty), ty_decl) => error ("In term " ^ (quote o Sign.string_of_term thy) t

    ^ ",\nconstant " ^ c ^ " with most general type\n"

    ^ Sign.string_of_typ thy ty

    ^ "\noccurs with type\n"

    ^ Sign.string_of_typ thy ty_decl);

(* parametrized application generators, for instantiation in object logic *)

(* (axiomatic extensions of extraction kernel *)

fun appgen_numeral int_of_numeral thy algbr funcgr strct (app as (c, ts)) trns =

  case try (int_of_numeral thy) (list_comb (Const c, ts))

   of SOME i =>

        trns

        |> appgen_default thy algbr funcgr strct app

        |-> (fn t => pair (CodegenThingol.INum (i, t)))

    | NONE =>

        trns

        |> appgen_default thy algbr funcgr strct app;

fun appgen_char char_to_index thy algbr funcgr strct (app as ((_, ty), _)) trns =

  case (char_to_index o list_comb o apfst Const) app

   of SOME i =>

        trns

        |> exprgen_type thy algbr funcgr strct ty

        ||>> appgen_default thy algbr funcgr strct app

        |-> (fn (_, t0) => pair (IChar (chr i, t0)))

    | NONE =>

        trns

        |> appgen_default thy algbr funcgr strct app;

fun appgen_case dest_case_expr thy algbr funcgr strct (app as (c_ty, ts)) trns =

  let

    val SOME ([], ((st, sty), ds)) = dest_case_expr thy (list_comb (Const c_ty, ts));

    fun clausegen (dt, bt) trns =

      trns

      |> exprgen_term thy algbr funcgr strct dt

      ||>> exprgen_term thy algbr funcgr strct bt;

  in

    trns

    |> exprgen_term thy algbr funcgr strct st

    ||>> exprgen_type thy algbr funcgr strct sty

    ||>> fold_map clausegen ds

    ||>> appgen_default thy algbr funcgr strct app

    |-> (fn (((se, sty), ds), e0) => pair (ICase (((se, sty), ds), e0)))

  end;

fun appgen_let thy algbr funcgr strct (app as (_, [st, ct])) trns =

  trns

  |> exprgen_term thy algbr funcgr strct ct

  ||>> exprgen_term thy algbr funcgr strct st

  ||>> appgen_default thy algbr funcgr strct app

  |-> (fn (((v, ty) `|-> be, se), e0) =>

            pair (ICase (((se, ty), case be

              of ICase (((IVar w, _), ds), _) => if v = w then ds else [(IVar v, be)]

               | _ => [(IVar v, be)]

            ), e0))

        | (_, e0) => pair e0);

fun add_appconst (c, appgen) thy =

  let

    val i = (length o fst o strip_type o Sign.the_const_type thy) c;

    val _ = Code.change thy (K CodegenThingol.empty_code);

  in

    (CodegenPackageData.map o apfst)

      (Symtab.update (c, (i, (appgen, stamp ())))) thy

  end;

(** abstype and constsubst interface **)

fun gen_abstyp prep_const prep_typ (raw_abstyp, raw_substtyp) raw_absconsts thy =

  let

    val abstyp = Type.no_tvars (prep_typ thy raw_abstyp);

    val substtyp = Type.no_tvars (prep_typ thy raw_substtyp);

    val absconsts = (map o pairself) (prep_const thy) raw_absconsts;

    val Type (abstyco, tys) = abstyp handle BIND => error ("bad type: " ^ Sign.string_of_typ thy abstyp);

    val typarms = map (fst o dest_TFree) tys handle MATCH => error ("bad type: " ^ Sign.string_of_typ thy abstyp);

    fun mk_index v = 

      let

        val k = find_index (fn w => v = w) typarms;

      in if k = ~1

        then error ("free type variable: " ^ quote v)

        else TFree (string_of_int k, [])

      end;

    val typpat = map_atyps (fn TFree (v, _) => mk_index v) substtyp;

    fun apply_typpat (Type (tyco, tys)) =

          let

            val tys' = map apply_typpat tys;

          in if tyco = abstyco then

            (map_atyps (fn TFree (n, _) => nth tys' (the (Int.fromString n)))) typpat

          else

            Type (tyco, tys')

          end

      | apply_typpat ty = ty;

    val string_of_typ = setmp show_sorts true (Sign.string_of_typ thy);

    fun add_consts (c1, c2) =

      let

        val _ = if CodegenNames.has_nsp CodegenNames.nsp_fun (CodegenNames.const thy c2)

          then ()

          else error ("not a function: " ^ CodegenConsts.string_of_const thy c2);

        val funcgr = CodegenFuncgr.mk_funcgr thy [c1, c2] [];

        val ty_map = CodegenFuncgr.get_func_typs funcgr;

        val ty1 = (apply_typpat o the o AList.lookup CodegenConsts.eq_const ty_map) c1;

        val ty2 = (the o AList.lookup CodegenConsts.eq_const ty_map) c2;

        val _ = if Sign.typ_equiv thy (ty1, ty2) then () else

          error ("Incompatiable type signatures of " ^ CodegenConsts.string_of_const thy c1

            ^ " and " ^ CodegenConsts.string_of_const thy c2 ^ ":\n"

            ^ string_of_typ ty1 ^ "\n" ^ string_of_typ ty2);

      in Consttab.update (c1, c2) end;

    val _ = Code.change thy (K CodegenThingol.empty_code);

  in

    thy

    |> (CodegenPackageData.map o apsnd) (fn (abstypes, abscs) =>

          (abstypes

          |> Symtab.update (abstyco, typpat),

          abscs

          |> fold add_consts absconsts)

       )

  end;

fun gen_constsubst prep_const raw_constsubsts thy =

  let

    val constsubsts = (map o pairself) (prep_const thy) raw_constsubsts;

    val string_of_typ = setmp show_sorts true (Sign.string_of_typ thy);

    fun add_consts (c1, c2) =

      let

        val _ = if CodegenNames.has_nsp CodegenNames.nsp_fun (CodegenNames.const thy c2)

          then ()

          else error ("not a function: " ^ CodegenConsts.string_of_const thy c2);

        val funcgr = CodegenFuncgr.mk_funcgr thy [c1, c2] [];

        val ty_map = CodegenFuncgr.get_func_typs funcgr;

        val ty1 = (the o AList.lookup CodegenConsts.eq_const ty_map) c1;

        val ty2 = (the o AList.lookup CodegenConsts.eq_const ty_map) c2;

        val _ = if Sign.typ_equiv thy (ty1, ty2) then () else

          error ("Incompatiable type signatures of " ^ CodegenConsts.string_of_const thy c1

            ^ " and " ^ CodegenConsts.string_of_const thy c2 ^ ":\n"

            ^ string_of_typ ty1 ^ "\n" ^ string_of_typ ty2);

      in Consttab.update (c1, c2) end;

    val _ = Code.change thy (K CodegenThingol.empty_code);

  in

    thy

    |> (CodegenPackageData.map o apsnd o apsnd) (fold add_consts constsubsts)

  end;

val abstyp = gen_abstyp CodegenConsts.norm Sign.certify_typ;

val abstyp_e = gen_abstyp CodegenConsts.read_const (fn thy => Sign.read_typ (thy, K NONE));

val constsubst = gen_constsubst CodegenConsts.norm;

val constsubst_e = gen_constsubst CodegenConsts.read_const;

(** code generation interfaces **)

fun generate thy (cs, rhss) targets init gen it =

  let

    val raw_funcgr = CodegenFuncgr.mk_funcgr thy cs rhss;

    val cs' = map_filter (Consttab.lookup ((snd o snd o CodegenPackageData.get) thy))

      (CodegenFuncgr.Constgraph.keys raw_funcgr);

    val funcgr = CodegenFuncgr.mk_funcgr thy cs' [];

    val qnaming = NameSpace.qualified_names NameSpace.default_naming;

    val algebr = ClassPackage.operational_algebra thy;

    val consttab = Consts.empty

      |> fold (fn (c, ty) => Consts.declare qnaming

           ((CodegenNames.const thy c, ty), true))

           (CodegenFuncgr.get_func_typs funcgr);

    val algbr = (algebr, consttab);

  in   

    Code.change_yield thy (CodegenThingol.start_transact init (gen thy algbr funcgr

        (true, targets) it))

    |> (fn (x, modl) => x)

  end;

fun codegen_term thy t =

  let

    fun const_typ (c, ty) =

      let

        val const = CodegenConsts.norm_of_typ thy (c, ty);

        val funcgr = CodegenFuncgr.mk_funcgr thy [const] [];

      in case CodegenFuncgr.get_funcs funcgr const

       of (thm :: _) => CodegenData.typ_func thy thm

        | [] => Sign.the_const_type thy c

      end;

    val ct = Thm.cterm_of thy t;

    val (thm, ct') = CodegenData.preprocess_cterm thy

      (const_typ) ct;

    val t' = Thm.term_of ct';

    val cs_rhss = CodegenConsts.consts_of thy t';

  in

    (thm, generate thy cs_rhss (SOME []) NONE exprgen_term' t')

  end;

fun const_of_idf thy =

  CodegenConsts.typ_of_inst thy o the o CodegenNames.const_rev thy;

fun get_root_module thy =

  Code.get thy;

fun eval_term thy (ref_spec, t) =

  let

    val _ = Term.fold_atyps (fn _ =>

      error ("Term" ^ Sign.string_of_term thy t ^ "is polymorhpic"))

      (Term.fastype_of t);

    val (_, t') = codegen_term thy t;

  in

    CodegenSerializer.eval_term thy (ref_spec, t') (Code.get thy)

  end;

(** toplevel interface and setup **)

local

structure P = OuterParse

and K = OuterKeyword

fun code raw_cs seris thy =

  let

    val cs = map (CodegenConsts.read_const thy) raw_cs;

    val targets = case map fst seris

     of [] => NONE

      | xs => SOME xs;

    val seris' = map_filter (fn (target, args as _ :: _) =>

      SOME (CodegenSerializer.get_serializer thy (target, args)) | _ => NONE) seris;

    fun generate' thy = case cs

     of [] => []

      | _ =>

          generate thy (cs, []) targets NONE (fold_map oooo ensure_def_const') cs;

    fun serialize' [] code seri =

          seri NONE code 

      | serialize' cs code seri =

          seri (SOME cs) code;

    val cs = generate' thy;

    val code = Code.get thy;

  in

    (map (serialize' cs code) seris'; ())

  end;

val (codeK, code_abstypeK, code_constsubstK) =

  ("code_gen", "code_abstype", "code_constsubst");

in

val codeP =

  OuterSyntax.improper_command codeK "generate and serialize executable code for constants" K.diag (

    Scan.repeat P.term

    -- Scan.repeat (P.$$$ "(" |--

        P.name -- P.arguments

        --| P.$$$ ")")

    >> (fn (raw_cs, seris) => Toplevel.keep (code raw_cs seris o Toplevel.theory_of))

  );

val code_abstypeP =

  OuterSyntax.command code_abstypeK "axiomatic abstypes for code generation" K.thy_decl (

    (P.typ -- P.typ -- Scan.optional (P.$$$ "where" |-- Scan.repeat1

        (P.term --| (P.$$$ "\\<equiv>" || P.$$$ "==") -- P.term)) [])

    >> (Toplevel.theory o uncurry abstyp_e)

  );

val code_constsubstP =

  OuterSyntax.command code_constsubstK "axiomatic constant substitutions for code generation" K.thy_decl (

    Scan.repeat1 (P.term --| (P.$$$ "\\<equiv>" || P.$$$ "==") -- P.term)

    >> (Toplevel.theory o constsubst_e)

  );

val _ = OuterSyntax.add_parsers [codeP, code_abstypeP, code_constsubstP];

end; (* local *)

end; (* struct *)