(*  Title:      Tools/code/code_package.ML

    ID:         $Id$

    Author:     Florian Haftmann, TU Muenchen

Code generator interfaces and Isar setup.

*)

signature CODE_PACKAGE =

sig

  val evaluate_conv: theory

    -> (term -> term * (CodeThingol.code -> CodeThingol.typscheme * CodeThingol.iterm

       -> string list -> thm))

    -> cterm -> thm;

  val evaluate_term: theory

    -> (term -> term * (CodeThingol.code -> CodeThingol.typscheme * CodeThingol.iterm

       -> string list -> 'a))

    -> term -> 'a;

  val eval_conv: string * (unit -> thm) option ref

    -> theory -> cterm -> string list -> thm;

  val eval_term: string * (unit -> 'a) option ref

    -> theory -> term -> string list -> 'a;

  val satisfies: theory -> term -> string list -> bool;

  val satisfies_ref: (unit -> bool) option ref;

  val codegen_shell_command: string (*theory name*) -> string (*cg expr*) -> unit;

end;

structure CodePackage : CODE_PACKAGE =

struct

(** code theorems **)

fun code_depgr thy [] = CodeFuncgr.make thy []

  | code_depgr thy consts =

      let

        val gr = CodeFuncgr.make thy consts;

        val select = Graph.all_succs gr consts;

      in

        gr

        |> Graph.subgraph (member (op =) select) 

        |> Graph.map_nodes ((apsnd o map) (AxClass.overload thy))

      end;

fun code_thms thy =

  Pretty.writeln o CodeFuncgr.pretty thy o code_depgr thy;

fun code_deps thy consts =

  let

    val gr = code_depgr thy consts;

    fun mk_entry (const, (_, (_, parents))) =

      let

        val name = CodeUnit.string_of_const thy const;

        val nameparents = map (CodeUnit.string_of_const thy) parents;

      in { name = name, ID = name, dir = "", unfold = true,

        path = "", parents = nameparents }

      end;

    val prgr = Graph.fold ((fn x => fn xs => xs @ [x]) o mk_entry) gr [];

  in Present.display_graph prgr end;

(** code generation interfaces **)

(* code data *)

structure Program = CodeDataFun

(

  type T = CodeThingol.code;

  val empty = CodeThingol.empty_code;

  fun merge _ = CodeThingol.merge_code;

  fun purge _ NONE _ = CodeThingol.empty_code

    | purge NONE _ _ = CodeThingol.empty_code

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

        let

          val cs_exisiting =

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

          val dels = (Graph.all_preds code

              o map (CodeName.const thy)

              o filter (member (op =) cs_exisiting)

            ) cs;

        in Graph.del_nodes dels code end;

);

(* generic generation combinators *)

val ensure_const = CodeThingol.ensure_const;

fun perhaps_const thy algbr funcgr c trns =

  case try (CodeThingol.ensure_const thy algbr funcgr c) trns

   of SOME (c, trns) => (SOME c, trns)

    | NONE => (NONE, trns);

fun generate thy funcgr f x =

  Program.change_yield thy (CodeThingol.transact thy funcgr

    (fn thy => fn funcgr => fn algbr => f thy funcgr algbr x));

(* export_code functionality *)

fun code thy permissive cs seris =

  let

    val code = Program.get thy;

    fun mk_seri_dest file = case file

     of NONE => CodeTarget.compile

      | SOME "-" => writeln o CodeTarget.string

      | SOME f => CodeTarget.file (Path.explode f)

    val _ = map (fn (((target, module), file), args) =>

      (mk_seri_dest file (CodeTarget.serialize thy target permissive module args code cs))) seris;

  in () end;

(* evaluation machinery *)

fun evaluate eval_kind thy evaluator =

  let

    fun evaluator'' evaluator''' funcgr t =

      let

        val ((code, (vs_ty_t, deps)), _) =

          generate thy funcgr CodeThingol.ensure_value t;

      in evaluator''' code vs_ty_t deps end;

    fun evaluator' t =

      let

        val (t', evaluator''') = evaluator t;

      in (t', evaluator'' evaluator''') end;

  in eval_kind thy evaluator' end

fun evaluate_conv thy = evaluate CodeFuncgr.eval_conv thy;

fun evaluate_term thy = evaluate CodeFuncgr.eval_term thy;

fun eval_ml reff args thy code ((vs, ty), t) deps =

  CodeTarget.eval thy reff code (t, ty) args;

fun eval evaluate term_of reff thy ct args =

  let

    val _ = if null (term_frees (term_of ct)) then () else error ("Term "

      ^ quote (Syntax.string_of_term_global thy (term_of ct))

      ^ " to be evaluated contains free variables");

  in evaluate thy (fn t => (t, eval_ml reff args thy)) ct end;

fun eval_conv reff = eval evaluate_conv Thm.term_of reff;

fun eval_term reff = eval evaluate_term I reff;

val satisfies_ref : (unit -> bool) option ref = ref NONE;

val satisfies = eval_term ("CodePackage.satisfies_ref", satisfies_ref);

(* code antiquotation *)

fun code_antiq (ctxt, args) = 

  let

    val thy = Context.theory_of ctxt;

    val (ts, (ctxt', args')) = Scan.repeat1 Args.term (ctxt, args);

    val cs = map (CodeUnit.check_const thy) ts;

    val (cs', code') = generate thy (CodeFuncgr.make thy cs)

      (fold_map ooo ensure_const) cs;

    val code'' = CodeTarget.sml_of thy code' cs' ^ " ()";

  in (("codevals", code''), (ctxt', args')) end;

(* const expressions *)

local

fun consts_of thy some_thyname =

  let

    val this_thy = Option.map ThyInfo.get_theory some_thyname |> the_default thy;

    val raw_cs = Symtab.fold (fn (c, (_, NONE)) => cons c | _ => I)

      ((snd o #constants o Consts.dest o #consts o Sign.rep_sg) this_thy) [];

    val cs = map (CodeUnit.subst_alias thy) raw_cs;

    fun belongs_here thyname c =

      not (exists (fn thy' => Sign.declared_const thy' c) (Theory.parents_of this_thy))

  in case some_thyname

   of NONE => cs

    | SOME thyname => filter (belongs_here thyname) cs

  end;

fun read_const_expr thy "*" = ([], consts_of thy NONE)

  | read_const_expr thy s = if String.isSuffix ".*" s

      then ([], consts_of thy (SOME (unsuffix ".*" s)))

      else ([CodeUnit.read_const thy s], []);

in

fun read_const_exprs thy select exprs =

  case (pairself flat o split_list o map (read_const_expr thy)) exprs

   of (consts, []) => (false, consts)

    | (consts, consts') => (true, consts @ select consts');

end; (*local*)

fun filter_generatable thy consts =

  let

    val (consts', funcgr) = CodeFuncgr.make_consts thy consts;

    val (consts'', _) = generate thy funcgr (fold_map ooo perhaps_const) consts';

    val consts''' = map_filter (fn (const, SOME _) => SOME const | (_, NONE) => NONE)

      (consts' ~~ consts'');

  in consts''' end;

fun generate_const_exprs thy raw_cs =

  let

    val (perm1, cs) = read_const_exprs thy

      (filter_generatable thy) raw_cs;

    val (perm2, cs') = case generate thy (CodeFuncgr.make thy cs)

      (fold_map ooo ensure_const) cs

     of ([], _) => (true, NONE)

      | (cs, _) => (false, SOME cs);

  in (perm1 orelse perm2, cs') end;

(** code properties **)

fun mk_codeprops thy all_cs sel_cs =

  let

    fun select (thmref, thm) = case try (Thm.unvarify o Drule.zero_var_indexes) thm

     of NONE => NONE

      | SOME thm => let

          val t = (ObjectLogic.drop_judgment thy o Thm.prop_of) thm;

          val cs = fold_aterms (fn Const (c, ty) =>

            cons (AxClass.unoverload_const thy (c, ty)) | _ => I) t [];

        in if exists (member (op =) sel_cs) cs

          andalso forall (member (op =) all_cs) cs

          then SOME (thmref, thm) else NONE end;

    fun mk_codeprop (thmref, thm) =

      let

        val t = ObjectLogic.drop_judgment thy (Thm.prop_of thm);

        val ty_judg = fastype_of t;

        val tfrees1 = fold_aterms (fn Const (c, ty) =>

          Term.add_tfreesT ty | _ => I) t [];

        val vars = Term.add_frees t [];

        val tfrees2 = fold (Term.add_tfreesT o snd) vars [];

        val tfrees' = subtract (op =) tfrees2 tfrees1 |> map TFree;

        val ty = map Term.itselfT tfrees' @ map snd vars ---> ty_judg;

        val tfree_vars = map Logic.mk_type tfrees';

        val c = Facts.string_of_ref thmref

          |> NameSpace.explode

          |> (fn [x] => [x] | (x::xs) => xs)

          |> space_implode "_"

        val propdef = (((c, ty), tfree_vars @ map Free vars), t);

      in if c = "" then NONE else SOME (thmref, propdef) end;

  in

    Facts.dest_static (PureThy.facts_of thy)

    |> maps Facts.selections

    |> map_filter select

    |> map_filter mk_codeprop

  end;

fun add_codeprops all_cs sel_cs thy =

  let

    val codeprops = mk_codeprops thy all_cs sel_cs;

    fun lift_name_yield f x = (Name.context, x) |> f ||> snd;

    fun add (thmref, (((raw_c, ty), ts), t)) (names, thy) =

      let

        val _ = warning ("Adding theorem " ^ quote (Facts.string_of_ref thmref)

          ^ " as code property " ^ quote raw_c);

        val ([raw_c'], names') = Name.variants [raw_c] names;

        val (const as Const (c, _), thy') = thy |> Sign.declare_const [] (raw_c', ty, NoSyn);

        val eq = Logic.mk_equals (list_comb (const, ts), t);

        val ([def], thy'') = thy' |> PureThy.add_defs_i false [((Thm.def_name raw_c', eq), [])];

      in ((c, def), (names', thy'')) end;

  in

    thy

    |> Sign.sticky_prefix "codeprop"

    |> lift_name_yield (fold_map add codeprops)

    ||> Sign.restore_naming thy

    |-> (fn c_thms => fold (Code.add_func o snd) c_thms #> pair c_thms)

  end;

(** interfaces and Isar setup **)

local

structure P = OuterParse

and K = OuterKeyword

fun code_cmd raw_cs seris thy =

  let

    val (permissive, cs) = generate_const_exprs thy raw_cs;

    val _ = code thy permissive cs seris;

  in () end;

fun code_thms_cmd thy =

  code_thms thy o snd o read_const_exprs thy (fst o CodeFuncgr.make_consts thy);

fun code_deps_cmd thy =

  code_deps thy o snd o read_const_exprs thy (fst o CodeFuncgr.make_consts thy);

fun code_props_cmd raw_cs seris thy =

  let

    val (_, all_cs) = generate_const_exprs thy ["*"];

    val (permissive, cs) = generate_const_exprs thy raw_cs;

    val (c_thms, thy') = add_codeprops (map (the o CodeName.const_rev thy) (these all_cs))

      (map (the o CodeName.const_rev thy) (these cs)) thy;

    val prop_cs = (filter_generatable thy' o map fst) c_thms;

    val _ = if null seris then () else (generate thy' (CodeFuncgr.make thy' prop_cs)

      (fold_map ooo ensure_const) prop_cs; ());

    val _ = if null seris then () else code thy' permissive

      (SOME (map (CodeName.const thy') prop_cs)) seris;

  in thy' end;

val (inK, module_nameK, fileK) = ("in", "module_name", "file");

fun code_exprP cmd =

  (Scan.repeat P.term

  -- Scan.repeat (P.$$$ inK |-- P.name

     -- Scan.option (P.$$$ module_nameK |-- P.name)

     -- Scan.option (P.$$$ fileK |-- P.name)

     -- Scan.optional (P.$$$ "(" |-- P.arguments --| P.$$$ ")") []

  ) >> (fn (raw_cs, seris) => cmd raw_cs seris));

val _ = OuterSyntax.keywords [inK, module_nameK, fileK];

val (codeK, code_thmsK, code_depsK, code_propsK) =

  ("export_code", "code_thms", "code_deps", "code_props");

in

val _ =

  OuterSyntax.command codeK "generate executable code for constants"

    K.diag (P.!!! (code_exprP code_cmd) >> (fn f => Toplevel.keep (f o Toplevel.theory_of)));

fun codegen_shell_command thyname cmd = Toplevel.program (fn _ =>

  (use_thy thyname; case Scan.read OuterLex.stopper (P.!!! (code_exprP code_cmd)) ((filter OuterLex.is_proper o OuterSyntax.scan) cmd)

   of SOME f => (writeln "Now generating code..."; f (theory thyname))

    | NONE => error ("Bad directive " ^ quote cmd)))

  handle TOPLEVEL_ERROR => OS.Process.exit OS.Process.failure;

val _ =

  OuterSyntax.improper_command code_thmsK "print system of defining equations for code" OuterKeyword.diag

    (Scan.repeat P.term

      >> (fn cs => Toplevel.no_timing o Toplevel.unknown_theory

        o Toplevel.keep ((fn thy => code_thms_cmd thy cs) o Toplevel.theory_of)));

val _ =

  OuterSyntax.improper_command code_depsK "visualize dependencies of defining equations for code" OuterKeyword.diag

    (Scan.repeat P.term

      >> (fn cs => Toplevel.no_timing o Toplevel.unknown_theory

        o Toplevel.keep ((fn thy => code_deps_cmd thy cs) o Toplevel.theory_of)));

val _ =

  OuterSyntax.command code_propsK "generate characteristic properties for executable constants"

    K.thy_decl (P.!!! (code_exprP code_props_cmd) >> Toplevel.theory);

val _ = ML_Context.value_antiq "code" code_antiq;

end; (*local*)

end; (*struct*)