(*  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

  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_attribute: string -> (Args.T list -> attribute * Args.T list) -> 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_consts: (xstring * string option * (term mixfix list *

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

  val assoc_consts_i: (xstring * typ option * (term mixfix list *

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

  val assoc_types: (xstring * (typ mixfix list *

    (string * string) list)) 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: theory -> typ -> typ -> bool

  val parens: Pretty.T -> Pretty.T

  val mk_app: bool -> Pretty.T -> Pretty.T list -> 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 -> int -> int -> term -> (string * term) list option

  val eval_result: 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 fillin_mixfix: ('a -> Pretty.T) -> 'a mixfix list -> 'a list -> Pretty.T

  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;

(**** 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 (typ_of (read_ctyp thy s))};

(* data kind 'Pure/codegen' *)

structure CodegenData = TheoryDataFun

(struct

  val name = "Pure/codegen";

  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,

     attrs: (string * (Args.T list -> attribute * Args.T list)) list,

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

     modules: codegr Symtab.table,

     test_params: test_params};

  val empty =

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

     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, attrs = attrs1,

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

     {codegens = codegens2, tycodegens = tycodegens2,

      consts = consts2, types = types2, attrs = attrs2,

      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),

     attrs = AList.merge (op =) (K true) (attrs1, attrs2),

     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, tycodegens, ...} : T) =

    Pretty.writeln (Pretty.chunks

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

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

end);

val _ = Context.add_setup CodegenData.init;

val print_codegens = CodegenData.print;

(**** 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, attrs, preprocs, modules, test_params} =

    CodegenData.get thy;

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

    consts = consts, types = types, attrs = attrs, 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, attrs, preprocs, modules, test_params} =

    CodegenData.get thy;

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

    consts = consts, types = types, attrs = attrs, 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, attrs, 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,

        attrs = attrs, 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, attrs, 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,

        attrs = attrs, preprocs = preprocs, modules = modules,

        test_params = test_params} thy

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

  end;

(**** code attribute ****)

fun add_attribute name att thy =

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

    CodegenData.get thy

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

      NONE => CodegenData.put {tycodegens = tycodegens,

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

        attrs = if name = "" then attrs @ [(name, att)] else (name, att) :: attrs,

        preprocs = preprocs, modules = modules,

        test_params = test_params} thy

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

  end;

fun mk_parser (a, p) = (if a = "" then Scan.succeed "" else Args.$$$ a) |-- p;

val code_attr =

  Attrib.syntax (Scan.peek (fn context => foldr op || Scan.fail (map mk_parser

    (#attrs (CodegenData.get (Context.theory_of context))))));

val _ = Context.add_setup

  (Attrib.add_attributes [("code", code_attr, "declare theorems for code generation")]);

(**** preprocessors ****)

fun add_preprocessor p thy =

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

    CodegenData.get thy

  in CodegenData.put {tycodegens = tycodegens,

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

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

    modules = modules, test_params = test_params} thy

  end;

fun preprocess thy ths =

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

  in Library.foldl (fn (ths, (_, f)) => f thy ths) (ths, 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 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;

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

fun gen_assoc_consts prep_type xs thy = Library.foldl (fn (thy, (s, tyopt, syn)) =>

  let

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

      CodegenData.get thy;

    val cname = Sign.intern_const thy s;

  in

    (case Sign.const_type thy cname of

       SOME T =>

         let val T' = (case tyopt of

                NONE => T

              | SOME ty =>

                  let val U = prep_type thy ty

                  in if Type.raw_instance (U, T) then U

                    else error ("Illegal type constraint for constant " ^ cname)

                  end)

         in

           if num_args_of (fst syn) > length (binder_types T') then

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

           else (case AList.lookup (op =) consts (cname, T') of

             NONE => CodegenData.put {codegens = codegens,

               tycodegens = tycodegens,

               consts = ((cname, T'), syn) :: consts,

               types = types, attrs = attrs, preprocs = preprocs,

               modules = modules, test_params = test_params} thy

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

         end

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

  end) (thy, xs);

val assoc_consts_i = gen_assoc_consts (K I);

val assoc_consts = gen_assoc_consts (typ_of oo read_ctyp);

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

fun assoc_types xs thy = Library.foldl (fn (thy, (s, syn)) =>

  let

    val {codegens, tycodegens, consts, types, attrs, 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, attrs = attrs,

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

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

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

  end) (thy, xs);

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.unpack 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.pack 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.unpack 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 ThmDatabase.is_ml_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 ThmDatabase.is_ml_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 ThmDatabase.is_ml_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 ThmDatabase.is_ml_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 = foldr add_term_names

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

    val reserved = names inter ThmDatabase.ml_reserved;

    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 thy T1 T2 =

  Sign.typ_instance thy (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 thy 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', snd (#axioms (Theory.rep_theory 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 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 thy 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" ^

        Sign.string_of_term 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" ^

        Sign.string_of_typ thy T)

    | SOME x => x);

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

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

fun pretty_fn [] p = [p]

  | pretty_fn (x::xs) p = Pretty.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 (Pretty.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;

fun fillin_mixfix f ms args =

  let

    fun fillin [] [] =

         []

      | fillin (Arg :: ms) (a :: args) =

          f a :: fillin ms args

      | fillin (Ignore :: ms) args =

          fillin ms args

      | fillin (Module :: ms) args =

          fillin ms args

      | fillin (Pretty p :: ms) args =

          p :: fillin ms args

      | fillin (Quote q :: ms) args =

          f q :: fillin ms args

  in Pretty.block (fillin ms args) end;

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

fun eta_expand t ts i =

  let

    val (Ts, _) = strip_type (fastype_of t);

    val j = i - length ts

  in

    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 (Pretty.str "(" ::

         separate (Pretty.brk 1) (p :: ps) @ [Pretty.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, ThmDatabase.ml_reserved)) (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 (Pretty.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 (Pretty.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', space_implode "\n" 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 (Pretty.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', Pretty.string_of

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

                         (if null args' then

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

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

                        [Pretty.str " =", Pretty.brk 1, p', Pretty.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 (Pretty.str "(" :: pretty_fn bs' p @

          [Pretty.str ")"])) ps)

      end

    | _ => NONE)

  end;

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

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

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

      SOME (gr, Pretty.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', space_implode "\n" xs ^ "\n")) gr''))),

                     p module'))

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

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

           end);

val _ = Context.add_setup

 (add_codegen "default" default_codegen #>

  add_tycodegen "default" default_tycodegen);

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 = foldr (uncurry Graph.add_edge_acyclic)

          (foldr (uncurry (Graph.new_node o rpair ())) Graph.empty modules)

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

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

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

        val modules' =

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

      in

        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 =

  setmp print_mode [] (Pretty.setmp_margin (!margin) (fn xs =>

  let

    val _ = assert (module <> "" orelse

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

      "missing module name";

    val graphs = get_modules thy;

    val defs = mk_deftab thy;

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

      (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.DUPS ks => error ("Duplicate code for " ^ commas ks);

    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 (Pretty.string_of (Pretty.block

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

val generate_code = gen_generate_code

  (fn thy => term_of o read_cterm thy o rpair TypeInfer.logicT);

(**** Reflection ****)

val strip_tname = implode o tl o explode;

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

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

  [Pretty.str "]"]);

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

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

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

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

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

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

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

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

  | mk_term_of gr module p (TFree (s, _)) = Pretty.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)

        (Pretty.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), _)) = Pretty.str

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

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

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

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

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

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

         map (mk_gen gr module true xs a) Ts @

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

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

fun test_term thy sz i t =

  let

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

      "Term to be tested contains type variables";

    val _ = assert (null (term_vars t))

      "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 = setmp print_mode [] (fn () => "structure TestTerm =\nstruct\n\n" ^

      space_implode "\n" (map snd code) ^

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

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

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

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

            Pretty.blk (0, separate Pretty.fbrk (map (fn ((s, T), s') =>

              Pretty.block [Pretty.str ("val " ^ s' ^ " ="), Pretty.brk 1,

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

              Pretty.str "i;"]) frees')),

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

            Pretty.block [Pretty.str "if ",

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

              Pretty.brk 1, Pretty.str "then NONE",

              Pretty.brk 1, Pretty.str "else ",

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

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

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

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

                     mk_app false (mk_term_of gr "Generated" false T)

                       [Pretty.str s'], Pretty.str ")"]]) frees')) @

                  [Pretty.str "]"])]],

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

      "\n\nend;\n") ();