(*  Title:      Tools/Code/code_target.ML

     Author:     Florian Haftmann, TU Muenchen

 Generic infrastructure for target language data.

 *)

 signature CODE_TARGET =

 sig

   val cert_tyco: Proof.context -> string -> string

   val read_tyco: Proof.context -> string -> string

   val export_code_for: Proof.context -> Path.T option -> string -> int option -> string -> Token.T list

     -> Code_Thingol.program -> bool -> Code_Symbol.T list -> unit

   val produce_code_for: Proof.context -> string -> int option -> string -> Token.T list

     -> Code_Thingol.program -> bool -> Code_Symbol.T list -> (string * string) list * string option list

   val present_code_for: Proof.context -> string -> int option -> string -> Token.T list

     -> Code_Thingol.program -> Code_Symbol.T list * Code_Symbol.T list -> string

   val check_code_for: Proof.context -> string -> bool -> Token.T list

     -> Code_Thingol.program -> bool -> Code_Symbol.T list -> unit

   val export_code: Proof.context -> bool -> string list

     -> (((string * string) * Path.T option) * Token.T list) list -> unit

   val produce_code: Proof.context -> bool -> string list

     -> string -> int option -> string -> Token.T list -> (string * string) list * string option list

   val present_code: Proof.context -> string list -> Code_Symbol.T list

     -> string -> int option -> string -> Token.T list -> string

   val check_code: Proof.context -> bool -> string list

     -> ((string * bool) * Token.T list) list -> unit

   val generatedN: string

   val evaluator: Proof.context -> string -> Code_Thingol.program

     -> Code_Symbol.T list -> bool -> ((string * class list) list * Code_Thingol.itype) * Code_Thingol.iterm

     -> (string * string) list * string

   type serializer

   type literals = Code_Printer.literals

   val add_target: string * { serializer: serializer, literals: literals,

     check: { env_var: string, make_destination: Path.T -> Path.T, make_command: string -> string } }

     -> theory -> theory

   val extend_target: string *

       (string * (Code_Thingol.program -> Code_Thingol.program))

     -> theory -> theory

   val assert_target: Proof.context -> string -> string

   val the_literals: Proof.context -> string -> literals

   type serialization

   val parse_args: 'a parser -> Token.T list -> 'a

   val serialization: (int -> Path.T option -> 'a -> unit)

     -> (Code_Symbol.T list -> int -> 'a -> (string * string) list * (Code_Symbol.T -> string option))

     -> 'a -> serialization

   val set_default_code_width: int -> theory -> theory

   type ('a, 'b, 'c, 'd, 'e, 'f) symbol_attr_decl

   type identifier_data

   val set_identifiers: (string, string, string, string, string, string) symbol_attr_decl

     -> theory -> theory

   val set_printings: (Code_Printer.raw_const_syntax, Code_Printer.tyco_syntax, string, unit, unit, (string * string list)) symbol_attr_decl

     -> theory -> theory

   val add_reserved: string -> string -> theory -> theory

   val codegen_tool: string (*theory name*) -> string (*export_code expr*) -> unit

   val setup: theory -> theory

 end;

 structure Code_Target : CODE_TARGET =

 struct

 open Basic_Code_Symbol;

 open Basic_Code_Thingol;

 type literals = Code_Printer.literals;

 type ('a, 'b, 'c, 'd, 'e, 'f) symbol_attr_decl =

   (string * (string * 'a option) list, string * (string * 'b option) list,

     class * (string * 'c option) list, (class * class) * (string * 'd option) list,

     (class * string) * (string * 'e option) list,

     string * (string * 'f option) list) Code_Symbol.attr;

 type identifier_data = (string list * string, string list * string, string list * string, string list * string,

   string list * string, string list * string) Code_Symbol.data;

 type tyco_syntax = Code_Printer.tyco_syntax;

 type raw_const_syntax = Code_Printer.raw_const_syntax;

 (** checking and parsing of symbols **)

 fun cert_const ctxt const =

   let

     val _ = if Sign.declared_const (Proof_Context.theory_of ctxt) const then ()

       else error ("No such constant: " ^ quote const);

   in const end;

 fun read_const ctxt = Code.read_const (Proof_Context.theory_of ctxt);

 fun cert_tyco ctxt tyco =

   let

     val _ = if Sign.declared_tyname (Proof_Context.theory_of ctxt) tyco then ()

       else error ("No such type constructor: " ^ quote tyco);

   in tyco end;

 fun read_tyco ctxt =

   #1 o dest_Type o Proof_Context.read_type_name ctxt {proper = true, strict = true};

 fun cert_class ctxt class =

   let

     val _ = Axclass.get_info (Proof_Context.theory_of ctxt) class;

   in class end;

 val parse_classrel_ident = Parse.class --| @{keyword "<"} -- Parse.class;

 fun cert_inst ctxt (class, tyco) =

   (cert_class ctxt class, cert_tyco ctxt tyco);

 fun read_inst ctxt (raw_tyco, raw_class) =

   (read_tyco ctxt raw_tyco, Proof_Context.read_class ctxt raw_class);

 val parse_inst_ident = Parse.xname --| @{keyword "::"} -- Parse.class;

 fun cert_syms ctxt =

   Code_Symbol.map_attr (apfst (cert_const ctxt)) (apfst (cert_tyco ctxt))

     (apfst (cert_class ctxt)) ((apfst o pairself) (cert_class ctxt)) (apfst (cert_inst ctxt)) I;

 fun read_syms ctxt =

   Code_Symbol.map_attr (apfst (read_const ctxt)) (apfst (read_tyco ctxt))

     (apfst (Proof_Context.read_class ctxt)) ((apfst o pairself) (Proof_Context.read_class ctxt)) (apfst (read_inst ctxt)) I;

 fun check_name is_module s =

   let

     val _ = if s = "" then error "Bad empty code name" else ();

     val xs = Long_Name.explode s;

     val xs' = if is_module

         then map (Name.desymbolize true) xs

       else if length xs < 2

         then error ("Bad code name without module component: " ^ quote s)

       else

         let

           val (ys, y) = split_last xs;

           val ys' = map (Name.desymbolize true) ys;

           val y' = Name.desymbolize false y;

         in ys' @ [y'] end;

   in if xs' = xs

     then if is_module then (xs, "") else split_last xs

     else error ("Invalid code name: " ^ quote s ^ "\n"

       ^ "better try " ^ quote (Long_Name.implode xs'))

   end;

 (** serializations and serializer **)

 (* serialization: abstract nonsense to cover different destinies for generated code *)

 datatype destination = Export of Path.T option | Produce | Present of Code_Symbol.T list;

 type serialization = int -> destination -> ((string * string) list * (Code_Symbol.T -> string option)) option;

 fun serialization output _ content width (Export some_path) =

       (output width some_path content; NONE)

   | serialization _ string content width Produce =

       string [] width content |> SOME

   | serialization _ string content width (Present syms) =

      string syms width content

      |> (apfst o map o apsnd) (Pretty.output (SOME width) o Pretty.str)

      |> SOME;

 fun export some_path f = (f (Export some_path); ());

 fun produce f = the (f Produce);

 fun present syms f = space_implode "\n\n" (map snd (fst (the (f (Present syms)))));

 (* serializers: functions producing serializations *)

 type serializer = Token.T list

   -> Proof.context

   -> {

     module_name: string,

     reserved_syms: string list,

     identifiers: identifier_data,

     includes: (string * Pretty.T) list,

     class_syntax: string -> string option,

     tyco_syntax: string -> Code_Printer.tyco_syntax option,

     const_syntax: string -> Code_Printer.const_syntax option }

   -> Code_Symbol.T list

   -> Code_Thingol.program

   -> serialization;

 datatype description =

     Fundamental of { serializer: serializer,

       literals: literals,

       check: { env_var: string, make_destination: Path.T -> Path.T,

         make_command: string -> string } }

   | Extension of string *

       (Code_Thingol.program -> Code_Thingol.program);

 (** theory data **)

 datatype target = Target of {

   serial: serial,

   description: description,

   reserved: string list,

   identifiers: identifier_data,

   printings: (Code_Printer.const_syntax, Code_Printer.tyco_syntax, string, unit, unit,

     (Pretty.T * string list)) Code_Symbol.data

 };

 fun make_target ((serial, description), (reserved, (identifiers, printings))) =

   Target { serial = serial, description = description, reserved = reserved,

     identifiers = identifiers, printings = printings };

 fun map_target f (Target { serial, description, reserved, identifiers, printings }) =

   make_target (f ((serial, description), (reserved, (identifiers, printings))));

 fun merge_target strict target (Target { serial = serial1, description = description,

   reserved = reserved1, identifiers = identifiers1, printings = printings1 },

     Target { serial = serial2, description = _,

       reserved = reserved2, identifiers = identifiers2, printings = printings2 }) =

   if serial1 = serial2 orelse not strict then

     make_target ((serial1, description), (merge (op =) (reserved1, reserved2),

       (Code_Symbol.merge_data (identifiers1, identifiers2),

         Code_Symbol.merge_data (printings1, printings2))))

   else

     error ("Incompatible targets: " ^ quote target);

 fun the_description (Target { description, ... }) = description;

 fun the_reserved (Target { reserved, ... }) = reserved;

 fun the_identifiers (Target { identifiers , ... }) = identifiers;

 fun the_printings (Target { printings, ... }) = printings;

 structure Targets = Theory_Data

 (

   type T = target Symtab.table * int;

   val empty = (Symtab.empty, 80);

   val extend = I;

   fun merge ((target1, width1), (target2, width2)) : T =

     (Symtab.join (merge_target true) (target1, target2), Int.max (width1, width2));

 );

 fun assert_target ctxt target =

   if Symtab.defined (fst (Targets.get (Proof_Context.theory_of ctxt))) target

   then target

   else error ("Unknown code target language: " ^ quote target);

 fun put_target (target, seri) thy =

   let

     val lookup_target = Symtab.lookup (fst (Targets.get thy));

     val _ = case seri

      of Extension (super, _) => if is_some (lookup_target super) then ()

           else error ("Unknown code target language: " ^ quote super)

       | _ => ();

     val overwriting = case (Option.map the_description o lookup_target) target

      of NONE => false

       | SOME (Extension _) => true

       | SOME (Fundamental _) => (case seri

          of Extension _ => error ("Will not overwrite existing target " ^ quote target)

           | _ => true);

     val _ = if overwriting

       then warning ("Overwriting existing target " ^ quote target)

       else ();

   in

     thy

     |> (Targets.map o apfst o Symtab.update)

         (target, make_target ((serial (), seri),

           ([], (Code_Symbol.empty_data, Code_Symbol.empty_data))))

   end;

 fun add_target (target, seri) = put_target (target, Fundamental seri);

 fun extend_target (target, (super, modify)) =

   put_target (target, Extension (super, modify));

 fun map_target_data target f thy =

   let

     val _ = assert_target (Proof_Context.init_global thy) target;

   in

     thy

     |> (Targets.map o apfst o Symtab.map_entry target o map_target o apsnd) f

   end;

 fun map_reserved target =

   map_target_data target o apfst;

 fun map_identifiers target =

   map_target_data target o apsnd o apfst;

 fun map_printings target =

   map_target_data target o apsnd o apsnd;

 fun set_default_code_width k = (Targets.map o apsnd) (K k);

 (** serializer usage **)

 (* montage *)

 fun the_fundamental ctxt =

   let

     val (targets, _) = Targets.get (Proof_Context.theory_of ctxt);

     fun fundamental target = case Symtab.lookup targets target

      of SOME data => (case the_description data

          of Fundamental data => data

           | Extension (super, _) => fundamental super)

       | NONE => error ("Unknown code target language: " ^ quote target);

   in fundamental end;

 fun the_literals ctxt = #literals o the_fundamental ctxt;

 fun collapse_hierarchy ctxt =

   let

     val (targets, _) = Targets.get (Proof_Context.theory_of ctxt);

     fun collapse target =

       let

         val data = case Symtab.lookup targets target

          of SOME data => data

           | NONE => error ("Unknown code target language: " ^ quote target);

       in case the_description data

        of Fundamental _ => (I, data)

         | Extension (super, modify) => let

             val (modify', data') = collapse super

           in (modify' #> modify, merge_target false target (data', data)) end

       end;

   in collapse end;

 local

 fun activate_target ctxt target =

   let

     val thy = Proof_Context.theory_of ctxt;

     val (_, default_width) = Targets.get thy;

     val (modify, data) = collapse_hierarchy ctxt target;

   in (default_width, data, modify) end;

 fun project_program ctxt syms_hidden syms1 program2 =

   let

     val syms2 = subtract (op =) syms_hidden syms1;

     val program3 = Code_Symbol.Graph.restrict (not o member (op =) syms_hidden) program2;

     val syms4 = Code_Symbol.Graph.all_succs program3 syms2;

     val unimplemented = Code_Thingol.unimplemented program3;

     val _ =

       if null unimplemented then ()

       else error ("No code equations for " ^

         commas (map (Proof_Context.markup_const ctxt) unimplemented));

     val program4 = Code_Symbol.Graph.restrict (member (op =) syms4) program3;

   in (syms4, program4) end;

 fun prepare_serializer ctxt (serializer : serializer) reserved identifiers

     printings module_name args proto_program syms =

   let

     val syms_hidden = Code_Symbol.symbols_of printings;

     val (syms_all, program) = project_program ctxt syms_hidden syms proto_program;

     fun select_include (name, (content, cs)) =

       if null cs orelse exists (fn c => member (op =) syms_all (Constant c)) cs

       then SOME (name, content) else NONE;

     val includes = map_filter select_include (Code_Symbol.dest_module_data printings);

   in

     (serializer args ctxt {

       module_name = module_name,

       reserved_syms = reserved,

       identifiers = identifiers,

       includes = includes,

       const_syntax = Code_Symbol.lookup_constant_data printings,

       tyco_syntax = Code_Symbol.lookup_type_constructor_data printings,

       class_syntax = Code_Symbol.lookup_type_class_data printings },

       (subtract (op =) syms_hidden syms, program))

   end;

 fun mount_serializer ctxt target some_width module_name args program syms =

   let

     val (default_width, data, modify) = activate_target ctxt target;

     val serializer = case the_description data

      of Fundamental seri => #serializer seri;

     val (prepared_serializer, (prepared_syms, prepared_program)) =

       prepare_serializer ctxt serializer

         (the_reserved data) (the_identifiers data) (the_printings data)

         module_name args (modify program) syms

     val width = the_default default_width some_width;

   in (fn program => fn syms => prepared_serializer syms program width, (prepared_syms, prepared_program)) end;

 fun invoke_serializer ctxt target some_width raw_module_name args program all_public syms =

   let

     val module_name = if raw_module_name = "" then ""

       else (check_name true raw_module_name; raw_module_name)

     val (mounted_serializer, (prepared_syms, prepared_program)) =

       mount_serializer ctxt target some_width module_name args program syms;

   in mounted_serializer prepared_program (if all_public then [] else prepared_syms) end;

 fun assert_module_name "" = error "Empty module name not allowed here"

   | assert_module_name module_name = module_name;

 fun using_master_directory ctxt =

   Option.map (Path.append (File.pwd ()) o Path.append (Thy_Load.master_directory (Proof_Context.theory_of ctxt)));

 in

 val generatedN = "Generated_Code";

 fun export_code_for ctxt some_path target some_width module_name args =

   export (using_master_directory ctxt some_path)

   ooo invoke_serializer ctxt target some_width module_name args;

 fun produce_code_for ctxt target some_width module_name args =

   let

     val serializer = invoke_serializer ctxt target some_width (assert_module_name module_name) args;

   in fn program => fn all_public => fn syms =>

     produce (serializer program all_public syms) |> apsnd (fn deresolve => map deresolve syms)

   end;

 fun present_code_for ctxt target some_width module_name args =

   let

     val serializer = invoke_serializer ctxt target some_width (assert_module_name module_name) args;

   in fn program => fn (syms, selects) =>

     present selects (serializer program false syms)

   end;

 fun check_code_for ctxt target strict args program all_public syms =

   let

     val { env_var, make_destination, make_command } =

       (#check o the_fundamental ctxt) target;

     fun ext_check p =

       let

         val destination = make_destination p;

         val _ = export (SOME destination) (invoke_serializer ctxt target (SOME 80)

           generatedN args program all_public syms);

         val cmd = make_command generatedN;

       in

         if Isabelle_System.bash ("cd " ^ File.shell_path p ^ " && " ^ cmd ^ " 2>&1") <> 0

         then error ("Code check failed for " ^ target ^ ": " ^ cmd)

         else ()

       end;

   in

     if getenv env_var = ""

     then if strict

       then error (env_var ^ " not set; cannot check code for " ^ target)

       else warning (env_var ^ " not set; skipped checking code for " ^ target)

     else Isabelle_System.with_tmp_dir "Code_Test" ext_check

   end;

 fun evaluation mounted_serializer prepared_program syms all_public ((vs, ty), t) =

   let

     val _ = if Code_Thingol.contains_dict_var t then

       error "Term to be evaluated contains free dictionaries" else ();

     val v' = singleton (Name.variant_list (map fst vs)) "a";

     val vs' = (v', []) :: vs;

     val ty' = ITyVar v' `-> ty;

     val program = prepared_program

       |> Code_Symbol.Graph.new_node (Code_Symbol.value,

           Code_Thingol.Fun (((vs', ty'), [(([IVar NONE], t), (NONE, true))]), NONE))

       |> fold (curry (perhaps o try o

           Code_Symbol.Graph.add_edge) Code_Symbol.value) syms;

     val (program_code, deresolve) =

       produce (mounted_serializer program (if all_public then [] else [Code_Symbol.value]));

     val value_name = the (deresolve Code_Symbol.value);

   in (program_code, value_name) end;

 fun evaluator ctxt target program syms =

   let

     val (mounted_serializer, (_, prepared_program)) =

       mount_serializer ctxt target NONE generatedN [] program syms;

   in evaluation mounted_serializer prepared_program syms end;

 end; (* local *)

 (* code generation *)

 fun prep_destination "" = NONE

   | prep_destination s = SOME (Path.explode s);

 fun export_code ctxt all_public cs seris =

   let

     val thy = Proof_Context.theory_of ctxt;

     val program = Code_Thingol.consts_program thy cs;

     val _ = map (fn (((target, module_name), some_path), args) =>

       export_code_for ctxt some_path target NONE module_name args program all_public (map Constant cs)) seris;

   in () end;

 fun export_code_cmd all_public raw_cs seris ctxt =

   export_code ctxt all_public

     (Code_Thingol.read_const_exprs ctxt raw_cs)

     ((map o apfst o apsnd) prep_destination seris);

 fun produce_code ctxt all_public cs target some_width some_module_name args =

   let

     val thy = Proof_Context.theory_of ctxt;

     val program = Code_Thingol.consts_program thy cs;

   in produce_code_for ctxt target some_width some_module_name args program all_public (map Constant cs) end;

 fun present_code ctxt cs syms target some_width some_module_name args =

   let

     val thy = Proof_Context.theory_of ctxt;

     val program = Code_Thingol.consts_program thy cs;

   in present_code_for ctxt target some_width some_module_name args program (map Constant cs, syms) end;

 fun check_code ctxt all_public cs seris =

   let

     val thy = Proof_Context.theory_of ctxt;

     val program = Code_Thingol.consts_program thy cs;

     val _ = map (fn ((target, strict), args) =>

       check_code_for ctxt target strict args program all_public (map Constant cs)) seris;

   in () end;

 fun check_code_cmd all_public raw_cs seris ctxt =

   check_code ctxt all_public

     (Code_Thingol.read_const_exprs ctxt raw_cs) seris;

 local

 val parse_const_terms = Scan.repeat1 Args.term

   >> (fn ts => fn ctxt => map (Code.check_const (Proof_Context.theory_of ctxt)) ts);

 fun parse_names category parse internalize mark_symbol =

   Scan.lift (Args.parens (Args.$$$ category)) |-- Scan.repeat1 parse

   >> (fn xs => fn ctxt => map (mark_symbol o internalize ctxt) xs);

 val parse_consts = parse_names "consts" Args.term

   (Code.check_const o Proof_Context.theory_of) Constant;

 val parse_types = parse_names "types" (Scan.lift Args.name)

   (Sign.intern_type o Proof_Context.theory_of) Type_Constructor;

 val parse_classes = parse_names "classes" (Scan.lift Args.name)

   (Sign.intern_class o Proof_Context.theory_of) Type_Class;

 val parse_instances = parse_names "instances" (Scan.lift (Args.name --| Args.$$$ "::" -- Args.name))

   (fn ctxt => fn (raw_tyco, raw_class) =>

     let

       val thy = Proof_Context.theory_of ctxt;

     in (Sign.intern_class thy raw_tyco, Sign.intern_type thy raw_class) end) Class_Instance;

 in

 val antiq_setup =

   Thy_Output.antiquotation @{binding code_stmts}

     (parse_const_terms --

       Scan.repeat (parse_consts || parse_types || parse_classes || parse_instances)

       -- Scan.lift (Args.parens (Args.name -- Scan.option Parse.int)))

     (fn {context = ctxt, ...} => fn ((mk_cs, mk_stmtss), (target, some_width)) =>

         present_code ctxt (mk_cs ctxt)

           (maps (fn f => f ctxt) mk_stmtss)

           target some_width "Example" []);

 end;

 (** serializer configuration **)

 (* reserved symbol names *)

 fun add_reserved target sym thy =

   let

     val (_, data) = collapse_hierarchy (Proof_Context.init_global thy) target;

     val _ = if member (op =) (the_reserved data) sym

       then error ("Reserved symbol " ^ quote sym ^ " already declared")

       else ();

   in

     thy

     |> map_reserved target (insert (op =) sym)

   end;

 (* checking of syntax *)

 fun check_const_syntax ctxt target c syn =

   if Code_Printer.requires_args syn > Code.args_number (Proof_Context.theory_of ctxt) c

   then error ("Too many arguments in syntax for constant " ^ quote c)

   else Code_Printer.prep_const_syntax (Proof_Context.theory_of ctxt) (the_literals ctxt target) c syn;

 fun check_tyco_syntax ctxt target tyco syn =

   if fst syn <> Sign.arity_number (Proof_Context.theory_of ctxt) tyco

   then error ("Number of arguments mismatch in syntax for type constructor " ^ quote tyco)

   else syn;

 (* custom symbol names *)

 fun arrange_name_decls x =

   let

     fun arrange is_module (sym, target_names) = map (fn (target, some_name) =>

       (target, (sym, Option.map (check_name is_module) some_name))) target_names;

   in

     Code_Symbol.maps_attr' (arrange false) (arrange false) (arrange false)

       (arrange false) (arrange false) (arrange true) x

   end;

 fun cert_name_decls ctxt = cert_syms ctxt #> arrange_name_decls;

 fun read_name_decls ctxt = read_syms ctxt #> arrange_name_decls;

 fun set_identifier (target, sym_name) = map_identifiers target (Code_Symbol.set_data sym_name);

 fun gen_set_identifiers prep_name_decl raw_name_decls thy =

   fold set_identifier (prep_name_decl (Proof_Context.init_global thy) raw_name_decls) thy;

 val set_identifiers = gen_set_identifiers cert_name_decls;

 val set_identifiers_cmd = gen_set_identifiers read_name_decls;

 (* custom printings *)

 fun arrange_printings prep_const ctxt =

   let

     fun arrange check (sym, target_syns) =

       map (fn (target, some_syn) => (target, (sym, Option.map (check ctxt target sym) some_syn))) target_syns;

   in

     Code_Symbol.maps_attr'

       (arrange check_const_syntax) (arrange check_tyco_syntax)

         (arrange ((K o K o K) I)) (arrange ((K o K o K) I)) (arrange ((K o K o K) I))

         (arrange (fn ctxt => fn _ => fn _ => fn (raw_content, raw_cs) =>

           (Code_Printer.str raw_content, map (prep_const ctxt) raw_cs)))

   end;

 fun cert_printings ctxt = cert_syms ctxt #> arrange_printings cert_const ctxt;

 fun read_printings ctxt = read_syms ctxt #> arrange_printings read_const ctxt;

 fun set_printing (target, sym_syn) = map_printings target (Code_Symbol.set_data sym_syn);

 fun gen_set_printings prep_print_decl raw_print_decls thy =

   fold set_printing (prep_print_decl (Proof_Context.init_global thy) raw_print_decls) thy;

 val set_printings = gen_set_printings cert_printings;

 val set_printings_cmd = gen_set_printings read_printings;

 (* concrete syntax *)

 fun parse_args f args =

   case Scan.read Token.stopper f args

    of SOME x => x

     | NONE => error "Bad serializer arguments";

 (** Isar setup **)

 fun parse_single_symbol_pragma parse_keyword parse_isa parse_target =

   parse_keyword |-- Parse.!!! (parse_isa --| (@{keyword "\<rightharpoonup>"} || @{keyword "=>"})

     -- Parse.and_list1 (@{keyword "("} |-- (Parse.name --| @{keyword ")"} -- Scan.option parse_target)));

 fun parse_symbol_pragma parse_const parse_tyco parse_class parse_classrel parse_inst parse_module =

   parse_single_symbol_pragma @{keyword "constant"} Parse.term parse_const

     >> Constant

   || parse_single_symbol_pragma @{keyword "type_constructor"} Parse.type_const parse_tyco

     >> Type_Constructor

   || parse_single_symbol_pragma @{keyword "type_class"} Parse.class parse_class

     >> Type_Class

   || parse_single_symbol_pragma @{keyword "class_relation"} parse_classrel_ident parse_classrel

     >> Class_Relation

   || parse_single_symbol_pragma @{keyword "class_instance"} parse_inst_ident parse_inst

     >> Class_Instance

   || parse_single_symbol_pragma @{keyword "code_module"} Parse.name parse_module

     >> Code_Symbol.Module;

 fun parse_symbol_pragmas parse_const parse_tyco parse_class parse_classrel parse_inst parse_module =

   Parse.enum1 "|" (Parse.group (fn () => "code symbol pragma")

     (parse_symbol_pragma parse_const parse_tyco parse_class parse_classrel parse_inst parse_module));

 val code_expr_argsP = Scan.optional (@{keyword "("} |-- Args.parse --| @{keyword ")"}) [];

 fun code_expr_inP all_public raw_cs =

   Scan.repeat (@{keyword "in"} |-- Parse.!!! (Parse.name

     -- Scan.optional (@{keyword "module_name"} |-- Parse.name) ""

     -- Scan.optional (@{keyword "file"} |-- Parse.name) ""

     -- code_expr_argsP))

       >> (fn seri_args => export_code_cmd all_public raw_cs seri_args);

 fun code_expr_checkingP all_public raw_cs =

   (@{keyword "checking"} |-- Parse.!!!

     (Scan.repeat (Parse.name -- ((@{keyword "?"} |-- Scan.succeed false) || Scan.succeed true)

     -- code_expr_argsP)))

       >> (fn seri_args => check_code_cmd all_public raw_cs seri_args);

 val code_exprP = (Scan.optional (@{keyword "open"} |-- Scan.succeed true) false

   -- Scan.repeat1 Parse.term)

   :|-- (fn (all_public, raw_cs) => (code_expr_checkingP all_public raw_cs || code_expr_inP all_public raw_cs));

 val _ =

   Outer_Syntax.command @{command_spec "code_reserved"}

     "declare words as reserved for target language"

     (Parse.name -- Scan.repeat1 Parse.name

       >> (fn (target, reserveds) => (Toplevel.theory o fold (add_reserved target)) reserveds));

 val _ =

   Outer_Syntax.command @{command_spec "code_identifier"} "declare mandatory names for code symbols"

     (parse_symbol_pragmas Parse.name Parse.name Parse.name Parse.name Parse.name Parse.name

       >> (Toplevel.theory o fold set_identifiers_cmd));

 val _ =

   Outer_Syntax.command @{command_spec "code_printing"} "declare dedicated printing for code symbols"

     (parse_symbol_pragmas (Code_Printer.parse_const_syntax) (Code_Printer.parse_tyco_syntax)

       Parse.string (Parse.minus >> K ()) (Parse.minus >> K ())

       (Parse.text -- Scan.optional (@{keyword "attach"} |-- Scan.repeat1 Parse.term) [])

       >> (Toplevel.theory o fold set_printings_cmd));

 val _ =

   Outer_Syntax.command @{command_spec "export_code"} "generate executable code for constants"

     (Parse.!!! code_exprP >> (fn f => Toplevel.keep (f o Toplevel.context_of)));

 (** external entrance point -- for codegen tool **)

 fun codegen_tool thyname cmd_expr =

   let

     val ctxt = Proof_Context.init_global (Thy_Info.get_theory thyname);

     val parse = Scan.read Token.stopper (Parse.!!! code_exprP) o

       (filter Token.is_proper o Outer_Syntax.scan Position.none);

   in case parse cmd_expr

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

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

   end;

 (** theory setup **)

 val setup = antiq_setup;

 end; (*struct*)