(*  Title:      Pure/codegen.ML

     ID:         $Id$

     Author:     Stefan Berghofer, TU Muenchen

 Generic code generator.

 *)

 signature CODEGEN =

 sig

   val quiet_mode : bool ref

   val message : string -> unit

   val mode : string list ref

   val margin : int ref

   val string_of : Pretty.T -> string

   val str : string -> Pretty.T

   datatype 'a mixfix =

       Arg

     | Ignore

     | Module

     | Pretty of Pretty.T

     | Quote of 'a;

   type deftab

   type node

   type codegr

   type 'a codegen

   val add_codegen: string -> term codegen -> theory -> theory

   val add_tycodegen: string -> typ codegen -> theory -> theory

   val add_preprocessor: (theory -> thm list -> thm list) -> theory -> theory

   val preprocess: theory -> thm list -> thm list

   val preprocess_term: theory -> term -> term

   val print_codegens: theory -> unit

   val generate_code: theory -> string list -> string -> (string * string) list ->

     (string * string) list * codegr

   val generate_code_i: theory -> string list -> string -> (string * term) list ->

     (string * string) list * codegr

   val assoc_const: string * (term mixfix list *

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

   val assoc_const_i: (string * typ) * (term mixfix list *

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

   val assoc_type: xstring * (typ mixfix list *

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

   val get_assoc_code: theory -> string * typ ->

     (term mixfix list * (string * string) list) option

   val get_assoc_type: theory -> string ->

     (typ mixfix list * (string * string) list) option

   val codegen_error: codegr -> string -> string -> 'a

   val invoke_codegen: theory -> deftab -> string -> string -> bool ->

     codegr * term -> codegr * Pretty.T

   val invoke_tycodegen: theory -> deftab -> string -> string -> bool ->

     codegr * typ -> codegr * Pretty.T

   val mk_id: string -> string

   val mk_qual_id: string -> string * string -> string

   val mk_const_id: string -> string -> codegr -> codegr * (string * string)

   val get_const_id: string -> codegr -> string * string

   val mk_type_id: string -> string -> codegr -> codegr * (string * string)

   val get_type_id: string -> codegr -> string * string

   val thyname_of_type: string -> theory -> string

   val thyname_of_const: string -> theory -> string

   val rename_terms: term list -> term list

   val rename_term: term -> term

   val new_names: term -> string list -> string list

   val new_name: term -> string -> string

   val if_library: 'a -> 'a -> 'a

   val get_defn: theory -> deftab -> string -> typ ->

     ((typ * (string * (term list * term))) * int option) option

   val is_instance: typ -> typ -> bool

   val parens: Pretty.T -> Pretty.T

   val mk_app: bool -> Pretty.T -> Pretty.T list -> Pretty.T

   val mk_tuple: Pretty.T list -> Pretty.T

   val mk_let: (Pretty.T * Pretty.T) list -> Pretty.T -> Pretty.T

   val eta_expand: term -> term list -> int -> term

   val strip_tname: string -> string

   val mk_type: bool -> typ -> Pretty.T

   val mk_term_of: codegr -> string -> bool -> typ -> Pretty.T

   val mk_gen: codegr -> string -> bool -> string list -> string -> typ -> Pretty.T

   val test_fn: (int -> (string * term) list option) ref

   val test_term: theory -> bool -> int -> int -> term -> (string * term) list option

   val auto_quickcheck: bool ref

   val auto_quickcheck_time_limit: int ref

   val eval_result: (unit -> term) ref

   val eval_term: theory -> term -> term

   val evaluation_conv: cterm -> thm

   val parse_mixfix: (string -> 'a) -> string -> 'a mixfix list

   val quotes_of: 'a mixfix list -> 'a list

   val num_args_of: 'a mixfix list -> int

   val replace_quotes: 'b list -> 'a mixfix list -> 'b mixfix list

   val mk_deftab: theory -> deftab

   val add_unfold: thm -> theory -> theory

   val get_node: codegr -> string -> node

   val add_edge: string * string -> codegr -> codegr

   val add_edge_acyclic: string * string -> codegr -> codegr

   val del_nodes: string list -> codegr -> codegr

   val map_node: string -> (node -> node) -> codegr -> codegr

   val new_node: string * node -> codegr -> codegr

 end;

 structure Codegen : CODEGEN =

 struct

 val quiet_mode = ref true;

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

 val mode = ref ([] : string list);

 val margin = ref 80;

 fun string_of p = (Pretty.string_of |>

   PrintMode.setmp [] |>

   Pretty.setmp_margin (!margin)) p;

 val str = PrintMode.setmp [] Pretty.str;

 (**** Mixfix syntax ****)

 datatype 'a mixfix =

     Arg

   | Ignore

   | Module

   | Pretty of Pretty.T

   | Quote of 'a;

 fun is_arg Arg = true

   | is_arg Ignore = true

   | is_arg _ = false;

 fun quotes_of [] = []

   | quotes_of (Quote q :: ms) = q :: quotes_of ms

   | quotes_of (_ :: ms) = quotes_of ms;

 fun args_of [] xs = ([], xs)

   | args_of (Arg :: ms) (x :: xs) = apfst (cons x) (args_of ms xs)

   | args_of (Ignore :: ms) (_ :: xs) = args_of ms xs

   | args_of (_ :: ms) xs = args_of ms xs;

 fun num_args_of x = length (List.filter is_arg x);

 (**** theory data ****)

 (* preprocessed definition table *)

 type deftab =

   (typ *              (* type of constant *)

     (string *         (* name of theory containing definition of constant *)

       (term list *    (* parameters *)

        term)))        (* right-hand side *)

   list Symtab.table;

 (* code dependency graph *)

 type nametab = (string * string) Symtab.table * unit Symtab.table;

 fun merge_nametabs ((tab, used), (tab', used')) =

   (Symtab.merge op = (tab, tab'), Symtab.merge op = (used, used'));

 type node =

   (exn option *    (* slot for arbitrary data *)

    string *        (* name of structure containing piece of code *)

    string);        (* piece of code *)

 type codegr =

   node Graph.T *

   (nametab *       (* table for assigned constant names *)

    nametab);       (* table for assigned type names *)

 val emptygr : codegr = (Graph.empty,

   ((Symtab.empty, Symtab.empty), (Symtab.empty, Symtab.empty)));

 (* type of code generators *)

 type 'a codegen =

   theory ->    (* theory in which generate_code was called *)

   deftab ->    (* definition table (for efficiency) *)

   codegr ->    (* code dependency graph *)

   string ->    (* node name of caller (for recording dependencies) *)

   string ->    (* module name of caller (for modular code generation) *)

   bool ->      (* whether to parenthesize generated expression *)

   'a ->        (* item to generate code from *)

   (codegr * Pretty.T) option;

 (* parameters for random testing *)

 type test_params =

   {size: int, iterations: int, default_type: typ option};

 fun merge_test_params

   {size = size1, iterations = iterations1, default_type = default_type1}

   {size = size2, iterations = iterations2, default_type = default_type2} =

   {size = Int.max (size1, size2),

    iterations = Int.max (iterations1, iterations2),

    default_type = case default_type1 of

        NONE => default_type2

      | _ => default_type1};

 val default_test_params : test_params =

   {size = 10, iterations = 100, default_type = NONE};

 fun set_size size ({iterations, default_type, ...} : test_params) =

   {size = size, iterations = iterations, default_type = default_type};

 fun set_iterations iterations ({size, default_type, ...} : test_params) =

   {size = size, iterations = iterations, default_type = default_type};

 fun set_default_type s thy ({size, iterations, ...} : test_params) =

   {size = size, iterations = iterations,

    default_type = SOME (Syntax.read_typ_global thy s)};

 (* theory data *)

 structure CodegenData = TheoryDataFun

 (

   type T =

     {codegens : (string * term codegen) list,

      tycodegens : (string * typ codegen) list,

      consts : ((string * typ) * (term mixfix list * (string * string) list)) list,

      types : (string * (typ mixfix list * (string * string) list)) list,

      preprocs: (stamp * (theory -> thm list -> thm list)) list,

      modules: codegr Symtab.table,

      test_params: test_params};

   val empty =

     {codegens = [], tycodegens = [], consts = [], types = [],

      preprocs = [], modules = Symtab.empty, test_params = default_test_params};

   val copy = I;

   val extend = I;

   fun merge _

     ({codegens = codegens1, tycodegens = tycodegens1,

       consts = consts1, types = types1,

       preprocs = preprocs1, modules = modules1, test_params = test_params1},

      {codegens = codegens2, tycodegens = tycodegens2,

       consts = consts2, types = types2,

       preprocs = preprocs2, modules = modules2, test_params = test_params2}) =

     {codegens = AList.merge (op =) (K true) (codegens1, codegens2),

      tycodegens = AList.merge (op =) (K true) (tycodegens1, tycodegens2),

      consts = AList.merge (op =) (K true) (consts1, consts2),

      types = AList.merge (op =) (K true) (types1, types2),

      preprocs = AList.merge (op =) (K true) (preprocs1, preprocs2),

      modules = Symtab.merge (K true) (modules1, modules2),

      test_params = merge_test_params test_params1 test_params2};

 );

 fun print_codegens thy =

   let val {codegens, tycodegens, ...} = CodegenData.get thy in

     Pretty.writeln (Pretty.chunks

       [Pretty.strs ("term code generators:" :: map fst codegens),

        Pretty.strs ("type code generators:" :: map fst tycodegens)])

   end;

 (**** access parameters for random testing ****)

 fun get_test_params thy = #test_params (CodegenData.get thy);

 fun map_test_params f thy =

   let val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

     CodegenData.get thy;

   in CodegenData.put {codegens = codegens, tycodegens = tycodegens,

     consts = consts, types = types, preprocs = preprocs,

     modules = modules, test_params = f test_params} thy

   end;

 (**** access modules ****)

 fun get_modules thy = #modules (CodegenData.get thy);

 fun map_modules f thy =

   let val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

     CodegenData.get thy;

   in CodegenData.put {codegens = codegens, tycodegens = tycodegens,

     consts = consts, types = types, preprocs = preprocs,

     modules = f modules, test_params = test_params} thy

   end;

 (**** add new code generators to theory ****)

 fun add_codegen name f thy =

   let val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

     CodegenData.get thy

   in (case AList.lookup (op =) codegens name of

       NONE => CodegenData.put {codegens = (name, f) :: codegens,

         tycodegens = tycodegens, consts = consts, types = types,

         preprocs = preprocs, modules = modules,

         test_params = test_params} thy

     | SOME _ => error ("Code generator " ^ name ^ " already declared"))

   end;

 fun add_tycodegen name f thy =

   let val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

     CodegenData.get thy

   in (case AList.lookup (op =) tycodegens name of

       NONE => CodegenData.put {tycodegens = (name, f) :: tycodegens,

         codegens = codegens, consts = consts, types = types,

         preprocs = preprocs, modules = modules,

         test_params = test_params} thy

     | SOME _ => error ("Code generator " ^ name ^ " already declared"))

   end;

 (**** preprocessors ****)

 fun add_preprocessor p thy =

   let val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

     CodegenData.get thy

   in CodegenData.put {tycodegens = tycodegens,

     codegens = codegens, consts = consts, types = types,

     preprocs = (stamp (), p) :: preprocs,

     modules = modules, test_params = test_params} thy

   end;

 fun preprocess thy =

   let val {preprocs, ...} = CodegenData.get thy

   in fold (fn (_, f) => f thy) preprocs end;

 fun preprocess_term thy t =

   let

     val x = Free (Name.variant (add_term_names (t, [])) "x", fastype_of t);

     (* fake definition *)

     val eq = setmp quick_and_dirty true (SkipProof.make_thm thy)

       (Logic.mk_equals (x, t));

     fun err () = error "preprocess_term: bad preprocessor"

   in case map prop_of (preprocess thy [eq]) of

       [Const ("==", _) $ x' $ t'] => if x = x' then t' else err ()

     | _ => err ()

   end;

 fun add_unfold eqn =

   let

     val thy = Thm.theory_of_thm eqn;

     val ctxt = ProofContext.init thy;

     val eqn' = LocalDefs.meta_rewrite_rule ctxt eqn;

     val names = term_consts (fst (Logic.dest_equals (prop_of eqn')));

     fun prep thy = map (fn th =>

       let val prop = prop_of th

       in

         if forall (fn name => exists_Const (equal name o fst) prop) names

         then rewrite_rule [eqn'] (Thm.transfer thy th)

         else th

       end)

   in add_preprocessor prep end;

 val _ = Context.>>

   (let

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

   in

     Context.map_theory (Code.add_attribute ("unfold", Scan.succeed (mk_attribute

       (fn thm => add_unfold thm #> Code.add_inline thm))))

   end);

 (**** associate constants with target language code ****)

 fun gen_assoc_const prep_const (raw_const, syn) thy =

   let

     val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

       CodegenData.get thy;

     val (cname, T) = prep_const thy raw_const;

   in

     if num_args_of (fst syn) > length (binder_types T) then

       error ("More arguments than in corresponding type of " ^ cname)

     else case AList.lookup (op =) consts (cname, T) of

       NONE => CodegenData.put {codegens = codegens,

         tycodegens = tycodegens,

         consts = ((cname, T), syn) :: consts,

         types = types, preprocs = preprocs,

         modules = modules, test_params = test_params} thy

     | SOME _ => error ("Constant " ^ cname ^ " already associated with code")

   end;

 val assoc_const_i = gen_assoc_const (K I);

 val assoc_const = gen_assoc_const CodeUnit.read_bare_const;

 (**** associate types with target language types ****)

 fun assoc_type (s, syn) thy =

   let

     val {codegens, tycodegens, consts, types, preprocs, modules, test_params} =

       CodegenData.get thy;

     val tc = Sign.intern_type thy s;

   in

     case Symtab.lookup (snd (#types (Type.rep_tsig (Sign.tsig_of thy)))) tc of

       SOME ((Type.LogicalType i, _), _) =>

         if num_args_of (fst syn) > i then

           error ("More arguments than corresponding type constructor " ^ s)

         else (case AList.lookup (op =) types tc of

           NONE => CodegenData.put {codegens = codegens,

             tycodegens = tycodegens, consts = consts,

             types = (tc, syn) :: types,

             preprocs = preprocs, modules = modules, test_params = test_params} thy

         | SOME _ => error ("Type " ^ tc ^ " already associated with code"))

     | _ => error ("Not a type constructor: " ^ s)

   end;

 fun get_assoc_type thy = AList.lookup (op =) ((#types o CodegenData.get) thy);

 (**** make valid ML identifiers ****)

 fun is_ascii_letdig x = Symbol.is_ascii_letter x orelse

   Symbol.is_ascii_digit x orelse Symbol.is_ascii_quasi x;

 fun dest_sym s = (case split_last (snd (take_prefix (equal "\\") (explode s))) of

     ("<" :: "^" :: xs, ">") => (true, implode xs)

   | ("<" :: xs, ">") => (false, implode xs)

   | _ => sys_error "dest_sym");

 fun mk_id s = if s = "" then "" else

   let

     fun check_str [] = []

       | check_str xs = (case take_prefix is_ascii_letdig xs of

           ([], " " :: zs) => check_str zs

         | ([], z :: zs) =>

           if size z = 1 then string_of_int (ord z) :: check_str zs

           else (case dest_sym z of

               (true, "isub") => check_str zs

             | (true, "isup") => "" :: check_str zs

             | (ctrl, s') => (if ctrl then "ctrl_" ^ s' else s') :: check_str zs)

         | (ys, zs) => implode ys :: check_str zs);

     val s' = space_implode "_" (maps (check_str o Symbol.explode) (NameSpace.explode s))

   in

     if Symbol.is_ascii_letter (hd (explode s')) then s' else "id_" ^ s'

   end;

 fun mk_long_id (p as (tab, used)) module s =

   let

     fun find_name [] = sys_error "mk_long_id"

       | find_name (ys :: yss) =

           let

             val s' = NameSpace.implode ys

             val s'' = NameSpace.append module s'

           in case Symtab.lookup used s'' of

               NONE => ((module, s'),

                 (Symtab.update_new (s, (module, s')) tab,

                  Symtab.update_new (s'', ()) used))

             | SOME _ => find_name yss

           end

   in case Symtab.lookup tab s of

       NONE => find_name (Library.suffixes1 (NameSpace.explode s))

     | SOME name => (name, p)

   end;

 (* module:  module name for caller                                        *)

 (* module': module name for callee                                        *)

 (* if caller and callee reside in different modules, use qualified access *)

 fun mk_qual_id module (module', s) =

   if module = module' orelse module' = "" then s else module' ^ "." ^ s;

 fun mk_const_id module cname (gr, (tab1, tab2)) =

   let

     val ((module, s), tab1') = mk_long_id tab1 module cname

     val s' = mk_id s;

     val s'' = if ML_Syntax.is_reserved s' then s' ^ "_const" else s'

   in ((gr, (tab1', tab2)), (module, s'')) end;

 fun get_const_id cname (gr, (tab1, tab2)) =

   case Symtab.lookup (fst tab1) cname of

     NONE => error ("get_const_id: no such constant: " ^ quote cname)

   | SOME (module, s) =>

       let

         val s' = mk_id s;

         val s'' = if ML_Syntax.is_reserved s' then s' ^ "_const" else s'

       in (module, s'') end;

 fun mk_type_id module tyname (gr, (tab1, tab2)) =

   let

     val ((module, s), tab2') = mk_long_id tab2 module tyname

     val s' = mk_id s;

     val s'' = if ML_Syntax.is_reserved s' then s' ^ "_type" else s'

   in ((gr, (tab1, tab2')), (module, s'')) end;

 fun get_type_id tyname (gr, (tab1, tab2)) =

   case Symtab.lookup (fst tab2) tyname of

     NONE => error ("get_type_id: no such type: " ^ quote tyname)

   | SOME (module, s) =>

       let

         val s' = mk_id s;

         val s'' = if ML_Syntax.is_reserved s' then s' ^ "_type" else s'

       in (module, s'') end;

 fun get_type_id' f tyname tab = apsnd f (get_type_id tyname tab);

 fun get_node (gr, x) k = Graph.get_node gr k;

 fun add_edge e (gr, x) = (Graph.add_edge e gr, x);

 fun add_edge_acyclic e (gr, x) = (Graph.add_edge_acyclic e gr, x);

 fun del_nodes ks (gr, x) = (Graph.del_nodes ks gr, x);

 fun map_node k f (gr, x) = (Graph.map_node k f gr, x);

 fun new_node p (gr, x) = (Graph.new_node p gr, x);

 fun theory_of_type s thy =

   if Sign.declared_tyname thy s

   then SOME (the_default thy (get_first (theory_of_type s) (Theory.parents_of thy)))

   else NONE;

 fun theory_of_const s thy =

   if Sign.declared_const thy s

   then SOME (the_default thy (get_first (theory_of_const s) (Theory.parents_of thy)))

   else NONE;

 fun thyname_of_type s thy = (case theory_of_type s thy of

     NONE => error ("thyname_of_type: no such type: " ^ quote s)

   | SOME thy' => Context.theory_name thy');

 fun thyname_of_const s thy = (case theory_of_const s thy of

     NONE => error ("thyname_of_const: no such constant: " ^ quote s)

   | SOME thy' => Context.theory_name thy');

 fun rename_terms ts =

   let

     val names = List.foldr add_term_names

       (map (fst o fst) (rev (fold Term.add_vars ts []))) ts;

     val reserved = filter ML_Syntax.is_reserved names;

     val (illegal, alt_names) = split_list (map_filter (fn s =>

       let val s' = mk_id s in if s = s' then NONE else SOME (s, s') end) names)

     val ps = (reserved @ illegal) ~~

       Name.variant_list names (map (suffix "'") reserved @ alt_names);

     fun rename_id s = AList.lookup (op =) ps s |> the_default s;

     fun rename (Var ((a, i), T)) = Var ((rename_id a, i), T)

       | rename (Free (a, T)) = Free (rename_id a, T)

       | rename (Abs (s, T, t)) = Abs (s, T, rename t)

       | rename (t $ u) = rename t $ rename u

       | rename t = t;

   in

     map rename ts

   end;

 val rename_term = hd o rename_terms o single;

 (**** retrieve definition of constant ****)

 fun is_instance T1 T2 =

   Type.raw_instance (T1, Logic.legacy_varifyT T2);

 fun get_assoc_code thy (s, T) = Option.map snd (find_first (fn ((s', T'), _) =>

   s = s' andalso is_instance T T') (#consts (CodegenData.get thy)));

 fun get_aux_code xs = map_filter (fn (m, code) =>

   if m = "" orelse member (op =) (!mode) m then SOME code else NONE) xs;

 fun mk_deftab thy =

   let

     val axmss = map (fn thy' => (Context.theory_name thy', Theory.axiom_table thy'))

       (thy :: Theory.ancestors_of thy);

     fun prep_def def = (case preprocess thy [def] of

       [def'] => prop_of def' | _ => error "mk_deftab: bad preprocessor");

     fun dest t =

       let

         val (lhs, rhs) = Logic.dest_equals t;

         val (c, args) = strip_comb lhs;

         val (s, T) = dest_Const c

       in if forall is_Var args then SOME (s, (T, (args, rhs))) else NONE

       end handle TERM _ => NONE;

     fun add_def thyname (name, t) = (case dest t of

         NONE => I

       | SOME _ => (case dest (prep_def (Thm.get_axiom_i thy name)) of

           NONE => I

         | SOME (s, (T, (args, rhs))) => Symtab.map_default (s, [])

             (cons (T, (thyname, split_last (rename_terms (args @ [rhs])))))))

   in

     fold (fn (thyname, axms) => Symtab.fold (add_def thyname) axms) axmss Symtab.empty

   end;

 fun get_defn thy defs s T = (case Symtab.lookup defs s of

     NONE => NONE

   | SOME ds =>

       let val i = find_index (is_instance T o fst) ds

       in if i >= 0 then

           SOME (List.nth (ds, i), if length ds = 1 then NONE else SOME i)

         else NONE

       end);

 (**** invoke suitable code generator for term / type ****)

 fun codegen_error (gr, _) dep s =

   error (s ^ "\nrequired by:\n" ^ commas (Graph.all_succs gr [dep]));

 fun invoke_codegen thy defs dep module brack (gr, t) = (case get_first

    (fn (_, f) => f thy defs gr dep module brack t) (#codegens (CodegenData.get thy)) of

       NONE => codegen_error gr dep ("Unable to generate code for term:\n" ^

         Syntax.string_of_term_global thy t)

     | SOME x => x);

 fun invoke_tycodegen thy defs dep module brack (gr, T) = (case get_first

    (fn (_, f) => f thy defs gr dep module brack T) (#tycodegens (CodegenData.get thy)) of

       NONE => codegen_error gr dep ("Unable to generate code for type:\n" ^

         Syntax.string_of_typ_global thy T)

     | SOME x => x);

 (**** code generator for mixfix expressions ****)

 fun parens p = Pretty.block [str "(", p, str ")"];

 fun pretty_fn [] p = [p]

   | pretty_fn (x::xs) p = str ("fn " ^ x ^ " =>") ::

       Pretty.brk 1 :: pretty_fn xs p;

 fun pretty_mixfix _ _ [] [] _ = []

   | pretty_mixfix module module' (Arg :: ms) (p :: ps) qs =

       p :: pretty_mixfix module module' ms ps qs

   | pretty_mixfix module module' (Ignore :: ms) ps qs =

       pretty_mixfix module module' ms ps qs

   | pretty_mixfix module module' (Module :: ms) ps qs =

       (if module <> module'

        then cons (str (module' ^ ".")) else I)

       (pretty_mixfix module module' ms ps qs)

   | pretty_mixfix module module' (Pretty p :: ms) ps qs =

       p :: pretty_mixfix module module' ms ps qs

   | pretty_mixfix module module' (Quote _ :: ms) ps (q :: qs) =

       q :: pretty_mixfix module module' ms ps qs;

 fun replace_quotes [] [] = []

   | replace_quotes xs (Arg :: ms) =

       Arg :: replace_quotes xs ms

   | replace_quotes xs (Ignore :: ms) =

       Ignore :: replace_quotes xs ms

   | replace_quotes xs (Module :: ms) =

       Module :: replace_quotes xs ms

   | replace_quotes xs (Pretty p :: ms) =

       Pretty p :: replace_quotes xs ms

   | replace_quotes (x::xs) (Quote _ :: ms) =

       Quote x :: replace_quotes xs ms;

 (**** default code generators ****)

 fun eta_expand t ts i =

   let

     val k = length ts;

     val Ts = Library.drop (k, binder_types (fastype_of t));

     val j = i - k

   in

     List.foldr (fn (T, t) => Abs ("x", T, t))

       (list_comb (t, ts @ map Bound (j-1 downto 0))) (Library.take (j, Ts))

   end;

 fun mk_app _ p [] = p

   | mk_app brack p ps = if brack then

        Pretty.block (str "(" ::

          separate (Pretty.brk 1) (p :: ps) @ [str ")"])

      else Pretty.block (separate (Pretty.brk 1) (p :: ps));

 fun new_names t xs = Name.variant_list

   (map (fst o fst o dest_Var) (term_vars t) union

     add_term_names (t, ML_Syntax.reserved_names)) (map mk_id xs);

 fun new_name t x = hd (new_names t [x]);

 fun if_library x y = if member (op =) (!mode) "library" then x else y;

 fun default_codegen thy defs gr dep module brack t =

   let

     val (u, ts) = strip_comb t;

     fun codegens brack = foldl_map (invoke_codegen thy defs dep module brack)

   in (case u of

       Var ((s, i), T) =>

         let

           val (gr', ps) = codegens true (gr, ts);

           val (gr'', _) = invoke_tycodegen thy defs dep module false (gr', T)

         in SOME (gr'', mk_app brack (str (s ^

            (if i=0 then "" else string_of_int i))) ps)

         end

     | Free (s, T) =>

         let

           val (gr', ps) = codegens true (gr, ts);

           val (gr'', _) = invoke_tycodegen thy defs dep module false (gr', T)

         in SOME (gr'', mk_app brack (str s) ps) end

     | Const (s, T) =>

       (case get_assoc_code thy (s, T) of

          SOME (ms, aux) =>

            let val i = num_args_of ms

            in if length ts < i then

                default_codegen thy defs gr dep module brack (eta_expand u ts i)

              else

                let

                  val (ts1, ts2) = args_of ms ts;

                  val (gr1, ps1) = codegens false (gr, ts1);

                  val (gr2, ps2) = codegens true (gr1, ts2);

                  val (gr3, ps3) = codegens false (gr2, quotes_of ms);

                  val (gr4, _) = invoke_tycodegen thy defs dep module false

                    (gr3, funpow (length ts) (hd o tl o snd o dest_Type) T);

                  val (module', suffix) = (case get_defn thy defs s T of

                      NONE => (if_library (thyname_of_const s thy) module, "")

                    | SOME ((U, (module', _)), NONE) =>

                        (if_library module' module, "")

                    | SOME ((U, (module', _)), SOME i) =>

                        (if_library module' module, " def" ^ string_of_int i));

                  val node_id = s ^ suffix;

                  fun p module' = mk_app brack (Pretty.block

                    (pretty_mixfix module module' ms ps1 ps3)) ps2

                in SOME (case try (get_node gr4) node_id of

                    NONE => (case get_aux_code aux of

                        [] => (gr4, p module)

                      | xs => (add_edge (node_id, dep) (new_node

                          (node_id, (NONE, module', cat_lines xs ^ "\n")) gr4),

                            p module'))

                  | SOME (_, module'', _) =>

                      (add_edge (node_id, dep) gr4, p module''))

                end

            end

        | NONE => (case get_defn thy defs s T of

            NONE => NONE

          | SOME ((U, (thyname, (args, rhs))), k) =>

              let

                val module' = if_library thyname module;

                val suffix = (case k of NONE => "" | SOME i => " def" ^ string_of_int i);

                val node_id = s ^ suffix;

                val (gr', (ps, def_id)) = codegens true (gr, ts) |>>>

                  mk_const_id module' (s ^ suffix);

                val p = mk_app brack (str (mk_qual_id module def_id)) ps

              in SOME (case try (get_node gr') node_id of

                  NONE =>

                    let

                      val _ = message ("expanding definition of " ^ s);

                      val (Ts, _) = strip_type U;

                      val (args', rhs') =

                        if not (null args) orelse null Ts then (args, rhs) else

                          let val v = Free (new_name rhs "x", hd Ts)

                          in ([v], betapply (rhs, v)) end;

                      val (gr1, p') = invoke_codegen thy defs node_id module' false

                        (add_edge (node_id, dep)

                           (new_node (node_id, (NONE, "", "")) gr'), rhs');

                      val (gr2, xs) = codegens false (gr1, args');

                      val (gr3, _) = invoke_tycodegen thy defs dep module false (gr2, T);

                      val (gr4, ty) = invoke_tycodegen thy defs node_id module' false (gr3, U);

                    in (map_node node_id (K (NONE, module', string_of

                        (Pretty.block (separate (Pretty.brk 1)

                          (if null args' then

                             [str ("val " ^ snd def_id ^ " :"), ty]

                           else str ("fun " ^ snd def_id) :: xs) @

                         [str " =", Pretty.brk 1, p', str ";"])) ^ "\n\n")) gr4,

                      p)

                    end

                | SOME _ => (add_edge (node_id, dep) gr', p))

              end))

     | Abs _ =>

       let

         val (bs, Ts) = ListPair.unzip (strip_abs_vars u);

         val t = strip_abs_body u

         val bs' = new_names t bs;

         val (gr1, ps) = codegens true (gr, ts);

         val (gr2, p) = invoke_codegen thy defs dep module false

           (gr1, subst_bounds (map Free (rev (bs' ~~ Ts)), t));

       in

         SOME (gr2, mk_app brack (Pretty.block (str "(" :: pretty_fn bs' p @

           [str ")"])) ps)

       end

     | _ => NONE)

   end;

 fun default_tycodegen thy defs gr dep module brack (TVar ((s, i), _)) =

       SOME (gr, str (s ^ (if i = 0 then "" else string_of_int i)))

   | default_tycodegen thy defs gr dep module brack (TFree (s, _)) =

       SOME (gr, str s)

   | default_tycodegen thy defs gr dep module brack (Type (s, Ts)) =

       (case AList.lookup (op =) ((#types o CodegenData.get) thy) s of

          NONE => NONE

        | SOME (ms, aux) =>

            let

              val (gr', ps) = foldl_map

                (invoke_tycodegen thy defs dep module false)

                (gr, fst (args_of ms Ts));

              val (gr'', qs) = foldl_map

                (invoke_tycodegen thy defs dep module false)

                (gr', quotes_of ms);

              val module' = if_library (thyname_of_type s thy) module;

              val node_id = s ^ " (type)";

              fun p module' = Pretty.block (pretty_mixfix module module' ms ps qs)

            in SOME (case try (get_node gr'') node_id of

                NONE => (case get_aux_code aux of

                    [] => (gr'', p module')

                  | xs => (fst (mk_type_id module' s

                        (add_edge (node_id, dep) (new_node (node_id,

                          (NONE, module', cat_lines xs ^ "\n")) gr''))),

                      p module'))

              | SOME (_, module'', _) =>

                  (add_edge (node_id, dep) gr'', p module''))

            end);

 val _ = Context.>> (Context.map_theory

  (add_codegen "default" default_codegen #>

   add_tycodegen "default" default_tycodegen));

 fun mk_tuple [p] = p

   | mk_tuple ps = Pretty.block (str "(" ::

       List.concat (separate [str ",", Pretty.brk 1] (map single ps)) @

         [str ")"]);

 fun mk_let bindings body =

   Pretty.blk (0, [str "let", Pretty.brk 1,

     Pretty.blk (0, separate Pretty.fbrk (map (fn (pat, rhs) =>

       Pretty.block [str "val ", pat, str " =", Pretty.brk 1,

       rhs, str ";"]) bindings)),

     Pretty.brk 1, str "in", Pretty.brk 1, body,

     Pretty.brk 1, str "end"]);

 fun mk_struct name s = "structure " ^ name ^ " =\nstruct\n\n" ^ s ^ "end;\n";

 fun add_to_module name s = AList.map_entry (op =) name (suffix s);

 fun output_code gr module xs =

   let

     val code = map_filter (fn s =>

       let val c as (_, module', _) = Graph.get_node gr s

       in if module = "" orelse module = module' then SOME (s, c) else NONE end)

         (rev (Graph.all_preds gr xs));

     fun string_of_cycle (a :: b :: cs) =

           let val SOME (x, y) = get_first (fn (x, (_, a', _)) =>

             if a = a' then Option.map (pair x)

               (find_first (equal b o #2 o Graph.get_node gr)

                 (Graph.imm_succs gr x))

             else NONE) code

           in x ^ " called by " ^ y ^ "\n" ^ string_of_cycle (b :: cs) end

       | string_of_cycle _ = ""

   in

     if module = "" then

       let

         val modules = distinct (op =) (map (#2 o snd) code);

         val mod_gr = fold_rev Graph.add_edge_acyclic

           (maps (fn (s, (_, module, _)) => map (pair module)

             (filter_out (equal module) (map (#2 o Graph.get_node gr)

               (Graph.imm_succs gr s)))) code)

           (fold_rev (Graph.new_node o rpair ()) modules Graph.empty);

         val modules' =

           rev (Graph.all_preds mod_gr (map (#2 o Graph.get_node gr) xs))

       in

         List.foldl (fn ((_, (_, module, s)), ms) => add_to_module module s ms)

           (map (rpair "") modules') code

       end handle Graph.CYCLES (cs :: _) =>

         error ("Cyclic dependency of modules:\n" ^ commas cs ^

           "\n" ^ string_of_cycle cs)

     else [(module, implode (map (#3 o snd) code))]

   end;

 fun gen_generate_code prep_term thy modules module xs =

   let

     val _ = (module <> "" orelse

         member (op =) (!mode) "library" andalso forall (equal "" o fst) xs)

       orelse error "missing module name";

     val graphs = get_modules thy;

     val defs = mk_deftab thy;

     val gr = new_node ("<Top>", (NONE, module, ""))

       (List.foldl (fn ((gr, (tab1, tab2)), (gr', (tab1', tab2'))) =>

         (Graph.merge (fn ((_, module, _), (_, module', _)) =>

            module = module') (gr, gr'),

          (merge_nametabs (tab1, tab1'), merge_nametabs (tab2, tab2')))) emptygr

            (map (fn s => case Symtab.lookup graphs s of

                 NONE => error ("Undefined code module: " ^ s)

               | SOME gr => gr) modules))

       handle Graph.DUP k => error ("Duplicate code for " ^ k);

     fun expand (t as Abs _) = t

       | expand t = (case fastype_of t of

           Type ("fun", [T, U]) => Abs ("x", T, t $ Bound 0) | _ => t);

     val (gr', ps) = foldl_map (fn (gr, (s, t)) => apsnd (pair s)

       (invoke_codegen thy defs "<Top>" module false (gr, t)))

         (gr, map (apsnd (expand o preprocess_term thy o prep_term thy)) xs);

     val code = map_filter

       (fn ("", _) => NONE

         | (s', p) => SOME (string_of (Pretty.block

           [str ("val " ^ s' ^ " ="), Pretty.brk 1, p, str ";"]))) ps;

     val code' = space_implode "\n\n" code ^ "\n\n";

     val code'' =

       map_filter (fn (name, s) =>

           if member (op =) (!mode) "library" andalso name = module andalso null code

           then NONE

           else SOME (name, mk_struct name s))

         ((if null code then I

           else add_to_module module code')

            (output_code (fst gr') (if_library "" module) ["<Top>"]))

   in

     (code'', del_nodes ["<Top>"] gr')

   end;

 val generate_code_i = gen_generate_code Sign.cert_term;

 val generate_code = gen_generate_code OldGoals.read_term;

 (**** Reflection ****)

 val strip_tname = implode o tl o explode;

 fun pretty_list xs = Pretty.block (str "[" ::

   flat (separate [str ",", Pretty.brk 1] (map single xs)) @

   [str "]"]);

 fun mk_type p (TVar ((s, i), _)) = str

       (strip_tname s ^ (if i = 0 then "" else string_of_int i) ^ "T")

   | mk_type p (TFree (s, _)) = str (strip_tname s ^ "T")

   | mk_type p (Type (s, Ts)) = (if p then parens else I) (Pretty.block

       [str "Type", Pretty.brk 1, str ("(\"" ^ s ^ "\","),

        Pretty.brk 1, pretty_list (map (mk_type false) Ts), str ")"]);

 fun mk_term_of gr module p (TVar ((s, i), _)) = str

       (strip_tname s ^ (if i = 0 then "" else string_of_int i) ^ "F")

   | mk_term_of gr module p (TFree (s, _)) = str (strip_tname s ^ "F")

   | mk_term_of gr module p (Type (s, Ts)) = (if p then parens else I)

       (Pretty.block (separate (Pretty.brk 1)

         (str (mk_qual_id module

           (get_type_id' (fn s' => "term_of_" ^ s') s gr)) ::

         maps (fn T =>

           [mk_term_of gr module true T, mk_type true T]) Ts)));

 (**** Test data generators ****)

 fun mk_gen gr module p xs a (TVar ((s, i), _)) = str

       (strip_tname s ^ (if i = 0 then "" else string_of_int i) ^ "G")

   | mk_gen gr module p xs a (TFree (s, _)) = str (strip_tname s ^ "G")

   | mk_gen gr module p xs a (Type (tyc as (s, Ts))) = (if p then parens else I)

       (Pretty.block (separate (Pretty.brk 1)

         (str (mk_qual_id module (get_type_id' (fn s' => "gen_" ^ s') s gr) ^

           (if member (op =) xs s then "'" else "")) ::

          (case tyc of

             ("fun", [T, U]) =>

               [mk_term_of gr module true T, mk_type true T,

                mk_gen gr module true xs a U, mk_type true U]

           | _ => maps (fn T =>

               [mk_gen gr module true xs a T, mk_type true T]) Ts) @

          (if member (op =) xs s then [str a] else []))));

 val test_fn : (int -> (string * term) list option) ref = ref (fn _ => NONE);

 fun test_term thy quiet sz i t =

   let

     val _ = (null (term_tvars t) andalso null (term_tfrees t)) orelse

       error "Term to be tested contains type variables";

     val _ = null (term_vars t) orelse

       error "Term to be tested contains schematic variables";

     val frees = map dest_Free (term_frees t);

     val frees' = frees ~~

       map (fn i => "arg" ^ string_of_int i) (1 upto length frees);

     val (code, gr) = setmp mode ["term_of", "test"]

       (generate_code_i thy [] "Generated") [("testf", list_abs_free (frees, t))];

     val s = "structure TestTerm =\nstruct\n\n" ^

       cat_lines (map snd code) ^

       "\nopen Generated;\n\n" ^ string_of

         (Pretty.block [str "val () = Codegen.test_fn :=",

           Pretty.brk 1, str ("(fn i =>"), Pretty.brk 1,

           mk_let (map (fn ((s, T), s') =>

               (mk_tuple [str s', str (s' ^ "_t")],

                Pretty.block [mk_gen gr "Generated" false [] "" T, Pretty.brk 1,

                  str "i"])) frees')

             (Pretty.block [str "if ",

               mk_app false (str "testf") (map (str o snd) frees'),

               Pretty.brk 1, str "then NONE",

               Pretty.brk 1, str "else ",

               Pretty.block [str "SOME ", Pretty.block (str "[" ::

                 flat (separate [str ",", Pretty.brk 1]

                   (map (fn ((s, T), s') => [Pretty.block

                     [str ("(" ^ quote (Symbol.escape s) ^ ","), Pretty.brk 1,

                      str (s' ^ "_t ())")]]) frees')) @

                   [str "]"])]]),

           str ");"]) ^

       "\n\nend;\n";

     val _ = ML_Context.eval_in (SOME (Context.Theory thy)) false Position.none s;

     fun iter f k = if k > i then NONE

       else (case (f () handle Match =>

           (if quiet then ()

            else warning "Exception Match raised in generated code"; NONE)) of

         NONE => iter f (k+1) | SOME x => SOME x);

     fun test k = if k > sz then NONE

       else (if quiet then () else priority ("Test data size: " ^ string_of_int k);

         case iter (fn () => !test_fn k) 1 of

           NONE => test (k+1) | SOME x => SOME x);

   in test 0 end;

 fun test_goal quiet ({size, iterations, default_type}, tvinsts) i assms state =

   let

     val thy = Proof.theory_of state;

     fun strip (Const ("all", _) $ Abs (_, _, t)) = strip t

       | strip t = t;

     val (_, (_, st)) = Proof.get_goal state;

     val (gi, frees) = Logic.goal_params (prop_of st) i;

     val gi' = ObjectLogic.atomize_term thy (map_types

       (map_type_tfree (fn p as (s, S) =>

         let val T = the_default (the_default (TFree p) default_type)

           (AList.lookup (op =) tvinsts s)

         in if Sign.of_sort thy (T, S) then T

           else error ("Type " ^ Syntax.string_of_typ_global thy T ^

             " to be substituted for variable " ^

             Syntax.string_of_typ_global thy (TFree p) ^ "\ndoes not have sort " ^

             Syntax.string_of_sort_global thy S)

         end))

       (Logic.list_implies (assms, subst_bounds (frees, strip gi))));

   in test_term thy quiet size iterations gi' end;

 fun pretty_counterex ctxt NONE = Pretty.str "No counterexamples found."

   | pretty_counterex ctxt (SOME cex) =

       Pretty.chunks (Pretty.str "Counterexample found:\n" ::

         map (fn (s, t) =>

           Pretty.block [Pretty.str (s ^ " ="), Pretty.brk 1, Syntax.pretty_term ctxt t]) cex);

 val auto_quickcheck = ref false;

 val auto_quickcheck_time_limit = ref 5000;

 fun test_goal' int state =

   let

     val ctxt = Proof.context_of state;

     val assms = map term_of (Assumption.assms_of ctxt);

     val params = get_test_params (Proof.theory_of state);

     fun test () =

       let

         val res = TimeLimit.timeLimit (Time.fromMilliseconds (!auto_quickcheck_time_limit))

           (try (test_goal true (params, []) 1 assms)) state;

       in

         case res of

           NONE => state

         | SOME NONE => state

         | SOME cex => Proof.goal_message (fn () => Pretty.chunks [Pretty.str "",

             Pretty.mark Markup.hilite (pretty_counterex ctxt cex)]) state

       end handle TimeLimit.TimeOut => (warning "Auto quickcheck: timeout."; state);

   in

     if int andalso !auto_quickcheck andalso not (!Toplevel.quiet)

     then test ()

     else state

   end;

 val _ = Context.>> (Specification.add_theorem_hook test_goal');

 (**** Evaluator for terms ****)

 val eval_result = ref (fn () => Bound 0);

 fun eval_term thy t =

   let val e =

     let

       val _ = (null (term_tvars t) andalso null (term_tfrees t)) orelse

         error "Term to be evaluated contains type variables";

       val _ = (null (term_vars t) andalso null (term_frees t)) orelse

         error "Term to be evaluated contains variables";

       val (code, gr) = setmp mode ["term_of"]

         (generate_code_i thy [] "Generated")

         [("result", Abs ("x", TFree ("'a", []), t))];

       val s = "structure EvalTerm =\nstruct\n\n" ^

         cat_lines (map snd code) ^

         "\nopen Generated;\n\n" ^ string_of

           (Pretty.block [str "val () = Codegen.eval_result := (fn () =>",

             Pretty.brk 1,

             mk_app false (mk_term_of gr "Generated" false (fastype_of t))

               [str "(result ())"],

             str ");"]) ^

         "\n\nend;\n";

       val _ = ML_Context.eval_in (SOME (Context.Theory thy)) false Position.none s;

     in !eval_result end;

   in e () end;

 fun print_evaluated_term s = Toplevel.keep (fn state =>

   let

     val ctxt = Toplevel.context_of state;

     val thy = ProofContext.theory_of ctxt;

     val t = eval_term thy (Syntax.read_term ctxt s);

     val T = Term.type_of t;

   in

     Pretty.writeln

       (Pretty.block [Pretty.quote (Syntax.pretty_term ctxt t), Pretty.fbrk,

         Pretty.str "::", Pretty.brk 1, Pretty.quote (Syntax.pretty_typ ctxt T)])

   end);

 exception Evaluation of term;

 fun evaluation_oracle (thy, Evaluation t) =

   Logic.mk_equals (t, eval_term thy t);

 fun evaluation_conv ct =

   let val thy = Thm.theory_of_cterm ct

   in Thm.invoke_oracle_i thy "Pure.evaluation" (thy, Evaluation (Thm.term_of ct)) end;

 val _ = Context.>> (Context.map_theory

   (Theory.add_oracle ("evaluation", evaluation_oracle)));

 (**** Interface ****)

 fun parse_mixfix rd s =

   (case Scan.finite Symbol.stopper (Scan.repeat

      (   $$ "_" >> K Arg

       || $$ "?" >> K Ignore

       || $$ "\\<module>" >> K Module

       || $$ "/" |-- Scan.repeat ($$ " ") >> (Pretty o Pretty.brk o length)

       || $$ "{" |-- $$ "*" |-- Scan.repeat1

            (   $$ "'" |-- Scan.one Symbol.is_regular

             || Scan.unless ($$ "*" -- $$ "}") (Scan.one Symbol.is_regular)) --|

          $$ "*" --| $$ "}" >> (Quote o rd o implode)

       || Scan.repeat1

            (   $$ "'" |-- Scan.one Symbol.is_regular

             || Scan.unless ($$ "_" || $$ "?" || $$ "\\<module>" || $$ "/" || $$ "{" |-- $$ "*")

                  (Scan.one Symbol.is_regular)) >> (Pretty o str o implode)))

        (Symbol.explode s) of

      (p, []) => p

    | _ => error ("Malformed annotation: " ^ quote s));

 structure P = OuterParse and K = OuterKeyword;

 val _ = List.app OuterKeyword.keyword ["attach", "file", "contains"];

 fun strip_whitespace s = implode (fst (take_suffix (equal "\n" orf equal " ")

   (snd (take_prefix (equal "\n" orf equal " ") (explode s))))) ^ "\n";

 val parse_attach = Scan.repeat (P.$$$ "attach" |--

   Scan.optional (P.$$$ "(" |-- P.xname --| P.$$$ ")") "" --

     (P.verbatim >> strip_whitespace));

 val _ =

   OuterSyntax.command "types_code"

   "associate types with target language types" K.thy_decl

     (Scan.repeat1 (P.xname --| P.$$$ "(" -- P.string --| P.$$$ ")" -- parse_attach) >>

      (fn xs => Toplevel.theory (fn thy => fold (assoc_type o

        (fn ((name, mfx), aux) => (name, (parse_mixfix

          (Syntax.read_typ_global thy) mfx, aux)))) xs thy)));

 val _ =

   OuterSyntax.command "consts_code"

   "associate constants with target language code" K.thy_decl

     (Scan.repeat1

        (P.term --|

         P.$$$ "(" -- P.string --| P.$$$ ")" -- parse_attach) >>

      (fn xs => Toplevel.theory (fn thy => fold (assoc_const o

        (fn ((const, mfx), aux) =>

          (const, (parse_mixfix (OldGoals.read_term thy) mfx, aux)))) xs thy)));

 fun parse_code lib =

   Scan.optional (P.$$$ "(" |-- P.enum "," P.xname --| P.$$$ ")") (!mode) --

   (if lib then Scan.optional P.name "" else P.name) --

   Scan.option (P.$$$ "file" |-- P.name) --

   (if lib then Scan.succeed []

    else Scan.optional (P.$$$ "imports" |-- Scan.repeat1 P.name) []) --|

   P.$$$ "contains" --

   (   Scan.repeat1 (P.name --| P.$$$ "=" -- P.term)

    || Scan.repeat1 (P.term >> pair "")) >>

   (fn ((((mode', module), opt_fname), modules), xs) => Toplevel.theory (fn thy =>

      let

        val mode'' = (if lib then insert (op =) "library" else I) (remove (op =) "library" mode');

        val (code, gr) = setmp mode mode'' (generate_code thy modules module) xs

      in ((case opt_fname of

          NONE =>

            ML_Context.eval_in (SOME (Context.Theory thy)) false Position.none

              (cat_lines (map snd code))

        | SOME fname =>

            if lib then

              app (fn (name, s) => File.write

                  (Path.append (Path.explode fname) (Path.basic (name ^ ".ML"))) s)

                (("ROOT", implode (map (fn (name, _) =>

                    "use \"" ^ name ^ ".ML\";\n") code)) :: code)

            else File.write (Path.explode fname) (snd (hd code)));

            if lib then thy

            else map_modules (Symtab.update (module, gr)) thy)

      end));

 val _ =

   OuterSyntax.command "code_library"

     "generates code for terms (one structure for each theory)" K.thy_decl

     (parse_code true);

 val _ =

   OuterSyntax.command "code_module"

     "generates code for terms (single structure, incremental)" K.thy_decl

     (parse_code false);

 val params =

   [("size", P.nat >> (K o set_size)),

    ("iterations", P.nat >> (K o set_iterations)),

    ("default_type", P.typ >> set_default_type)];

 val parse_test_params = P.short_ident :|-- (fn s =>

   P.$$$ "=" |-- (AList.lookup (op =) params s |> the_default Scan.fail));

 fun parse_tyinst xs =

   (P.type_ident --| P.$$$ "=" -- P.typ >> (fn (v, s) => fn thy =>

     fn (x, ys) => (x, (v, Syntax.read_typ_global thy s) :: ys))) xs;

 val _ =

   OuterSyntax.command "quickcheck_params" "set parameters for random testing" K.thy_decl

     (P.$$$ "[" |-- P.list1 parse_test_params --| P.$$$ "]" >>

       (fn fs => Toplevel.theory (fn thy =>

          map_test_params (Library.apply (map (fn f => f thy) fs)) thy)));

 val _ =

   OuterSyntax.command "quickcheck" "try to find counterexample for subgoal" K.diag

   (Scan.option (P.$$$ "[" |-- P.list1

     (   parse_test_params >> (fn f => fn thy => apfst (f thy))

      || parse_tyinst) --| P.$$$ "]") -- Scan.optional P.nat 1 >>

     (fn (ps, g) => Toplevel.keep (fn st => Toplevel.proof_of st |>

       test_goal false (Library.apply (the_default []

           (Option.map (map (fn f => f (Toplevel.theory_of st))) ps))

         (get_test_params (Toplevel.theory_of st), [])) g [] |>

       pretty_counterex (Toplevel.context_of st) |> Pretty.writeln)));

 val _ =

   OuterSyntax.improper_command "value" "read, evaluate and print term" K.diag

     (P.term >> (Toplevel.no_timing oo print_evaluated_term));

 end;

 val auto_quickcheck = Codegen.auto_quickcheck;

 val auto_quickcheck_time_limit = Codegen.auto_quickcheck_time_limit;