(*  Title:      Tools/Code/code_scala.ML

    Author:     Florian Haftmann, TU Muenchen

Serializer for Scala.

*)

signature CODE_SCALA =

sig

  val target: string

  val setup: theory -> theory

end;

structure Code_Scala : CODE_SCALA =

struct

val target = "Scala";

open Basic_Code_Thingol;

open Code_Printer;

infixr 5 @@;

infixr 5 @|;

(** Scala serializer **)

fun print_scala_stmt labelled_name syntax_tyco syntax_const reserved

    args_num is_singleton_constr (deresolve, deresolve_full) =

  let

    fun lookup_tyvar tyvars = lookup_var tyvars o first_upper;

    fun intro_tyvars vs = intro_vars (map (first_upper o fst) vs);

    fun print_tyco_expr tyvars fxy (tyco, tys) = applify "[" "]"

          (print_typ tyvars NOBR) fxy ((str o deresolve) tyco) tys

    and print_typ tyvars fxy (tyco `%% tys) = (case syntax_tyco tyco

         of NONE => print_tyco_expr tyvars fxy (tyco, tys)

          | SOME (i, print) => print (print_typ tyvars) fxy tys)

      | print_typ tyvars fxy (ITyVar v) = (str o lookup_tyvar tyvars) v;

    fun print_dicttyp tyvars (class, ty) = print_tyco_expr tyvars NOBR (class, [ty]);

    fun print_tupled_typ tyvars ([], ty) =

          print_typ tyvars NOBR ty

      | print_tupled_typ tyvars ([ty1], ty2) =

          concat [print_typ tyvars BR ty1, str "=>", print_typ tyvars NOBR ty2]

      | print_tupled_typ tyvars (tys, ty) =

          concat [enum "," "(" ")" (map (print_typ tyvars NOBR) tys),

            str "=>", print_typ tyvars NOBR ty];

    fun constraint p1 p2 = Pretty.block [p1, str ":", Pretty.brk 1, p2];

    fun print_var vars NONE = str "_"

      | print_var vars (SOME v) = (str o lookup_var vars) v

    fun print_term tyvars is_pat some_thm vars fxy (IConst c) =

          print_app tyvars is_pat some_thm vars fxy (c, [])

      | print_term tyvars is_pat some_thm vars fxy (t as (t1 `$ t2)) =

          (case Code_Thingol.unfold_const_app t

           of SOME app => print_app tyvars is_pat some_thm vars fxy app

            | _ => applify "(" ")" (print_term tyvars is_pat some_thm vars NOBR) fxy

                (print_term tyvars is_pat some_thm vars BR t1) [t2])

      | print_term tyvars is_pat some_thm vars fxy (IVar v) =

          print_var vars v

      | print_term tyvars is_pat some_thm vars fxy ((v, ty) `|=> t) =

          let

            val vars' = intro_vars (the_list v) vars;

          in

            concat [

              enclose "(" ")" [constraint (print_var vars' v) (print_typ tyvars NOBR ty)],

              str "=>",

              print_term tyvars false some_thm vars' NOBR t

            ]

          end 

      | print_term tyvars is_pat some_thm vars fxy (ICase (cases as (_, t0))) =

          (case Code_Thingol.unfold_const_app t0

           of SOME (c_ts as ((c, _), _)) => if is_none (syntax_const c)

                then print_case tyvars some_thm vars fxy cases

                else print_app tyvars is_pat some_thm vars fxy c_ts

            | NONE => print_case tyvars some_thm vars fxy cases)

    and print_app tyvars is_pat some_thm vars fxy

        (app as ((c, ((arg_typs, _), function_typs)), ts)) =

      let

        val k = length ts;

        val arg_typs' = if is_pat orelse

          (is_none (syntax_const c) andalso is_singleton_constr c) then [] else arg_typs;

        val (l, print') = case syntax_const c

         of NONE => (args_num c, fn fxy => fn ts => applify "(" ")"

              (print_term tyvars is_pat some_thm vars NOBR) fxy

                (applify "[" "]" (print_typ tyvars NOBR)

                  NOBR ((str o deresolve) c) arg_typs') ts)

          | SOME (Plain_const_syntax (k, s)) => (k, fn fxy => fn ts => applify "(" ")"

              (print_term tyvars is_pat some_thm vars NOBR) fxy

                (applify "[" "]" (print_typ tyvars NOBR)

                  NOBR (str s) arg_typs') ts)

          | SOME (Complex_const_syntax (k, print)) =>

              (k, fn fxy => fn ts => print (print_term tyvars is_pat some_thm) some_thm vars fxy

                (ts ~~ take k function_typs))

      in if k = l then print' fxy ts

      else if k < l then

        print_term tyvars is_pat some_thm vars fxy (Code_Thingol.eta_expand l app)

      else let

        val (ts1, ts23) = chop l ts;

      in

        Pretty.block (print' BR ts1 :: map (fn t => Pretty.block

          [str ".apply(", print_term tyvars is_pat some_thm vars NOBR t, str ")"]) ts23)

      end end

    and print_bind tyvars some_thm fxy p =

      gen_print_bind (print_term tyvars true) some_thm fxy p

    and print_case tyvars some_thm vars fxy (cases as ((_, [_]), _)) =

          let

            val (binds, body) = Code_Thingol.unfold_let (ICase cases);

            fun print_match ((IVar NONE, _), t) vars =

                  ((true, print_term tyvars false some_thm vars NOBR t), vars)

              | print_match ((pat, ty), t) vars =

                  vars

                  |> print_bind tyvars some_thm BR pat

                  |>> (fn p => (false, concat [str "val", constraint p (print_typ tyvars NOBR ty),

                      str "=", print_term tyvars false some_thm vars NOBR t]))

            val (seps_ps, vars') = fold_map print_match binds vars;

            val all_seps_ps = seps_ps @ [(true, print_term tyvars false some_thm vars' NOBR body)];

            fun insert_seps [(_, p)] = [p]

              | insert_seps ((_, p) :: (seps_ps as (sep, _) :: _)) =

                  (if sep then Pretty.block [p, str ";"] else p) :: insert_seps seps_ps

          in brackify_block fxy (str "{") (insert_seps all_seps_ps) (str "}")

          end

      | print_case tyvars some_thm vars fxy (((t, ty), clauses as _ :: _), _) =

          let

            fun print_select (pat, body) =

              let

                val (p_pat, vars') = print_bind tyvars some_thm NOBR pat vars;

                val p_body = print_term tyvars false some_thm vars' NOBR body

              in concat [str "case", p_pat, str "=>", p_body] end;

          in brackify_block fxy

            (concat [print_term tyvars false some_thm vars NOBR t, str "match", str "{"])

            (map print_select clauses)

            (str "}") 

          end

      | print_case tyvars some_thm vars fxy ((_, []), _) =

          (brackify fxy o Pretty.breaks o map str) ["error(\"empty case\")"];

    fun print_context tyvars vs name = applify "[" "]"

      (fn (v, sort) => (Pretty.block o map str)

        (lookup_tyvar tyvars v :: maps (fn sort => [": ", deresolve sort]) sort))

          NOBR ((str o deresolve) name) vs;

    fun print_defhead tyvars vars name vs params tys ty =

      Pretty.block [str "def ", constraint (applify "(" ")" (fn (param, ty) =>

        constraint ((str o lookup_var vars) param) (print_typ tyvars NOBR ty))

          NOBR (print_context tyvars vs name) (params ~~ tys)) (print_typ tyvars NOBR ty),

            str " ="];

    fun print_def name (vs, ty) [] =

          let

            val (tys, ty') = Code_Thingol.unfold_fun ty;

            val params = Name.invents (snd reserved) "a" (length tys);

            val tyvars = intro_tyvars vs reserved;

            val vars = intro_vars params reserved;

          in

            concat [print_defhead tyvars vars name vs params tys ty',

              str ("error(\"" ^ name ^ "\")")]

          end

      | print_def name (vs, ty) eqs =

          let

            val tycos = fold (fn ((ts, t), _) =>

              fold Code_Thingol.add_tyconames (t :: ts)) eqs [];

            val tyvars = reserved

              |> intro_base_names

                   (is_none o syntax_tyco) deresolve tycos

              |> intro_tyvars vs;

            val simple = case eqs

             of [((ts, _), _)] => forall Code_Thingol.is_IVar ts

              | _ => false;

            val consts = fold Code_Thingol.add_constnames

              (map (snd o fst) eqs) [];

            val vars1 = reserved

              |> intro_base_names

                   (is_none o syntax_const) deresolve consts

            val params = if simple

              then (map (fn IVar (SOME x) => x) o fst o fst o hd) eqs

              else aux_params vars1 (map (fst o fst) eqs);

            val vars2 = intro_vars params vars1;

            val (tys', ty') = Code_Thingol.unfold_fun_n (length params) ty;

            fun print_tuple [p] = p

              | print_tuple ps = enum "," "(" ")" ps;

            fun print_rhs vars' ((_, t), (some_thm, _)) =

              print_term tyvars false some_thm vars' NOBR t;

            fun print_clause (eq as ((ts, _), (some_thm, _))) =

              let

                val vars' = intro_vars ((fold o Code_Thingol.fold_varnames)

                  (insert (op =)) ts []) vars1;

              in

                concat [str "case",

                  print_tuple (map (print_term tyvars true some_thm vars' NOBR) ts),

                  str "=>", print_rhs vars' eq]

              end;

            val head = print_defhead tyvars vars2 name vs params tys' ty';

          in if simple then

            concat [head, print_rhs vars2 (hd eqs)]

          else

            Pretty.block_enclose

              (concat [head, print_tuple (map (str o lookup_var vars2) params),

                str "match", str "{"], str "}")

              (map print_clause eqs)

          end;

    val print_method = str o Library.enclose "`" "`" o space_implode "+"

      o Long_Name.explode o deresolve_full;

    fun print_stmt (name, Code_Thingol.Fun (_, (((vs, ty), raw_eqs), _))) =

          print_def name (vs, ty) (filter (snd o snd) raw_eqs)

      | print_stmt (name, Code_Thingol.Datatype (_, (vs, cos))) =

          let

            val tyvars = intro_tyvars vs reserved;

            fun print_co ((co, _), []) =

                  concat [str "final", str "case", str "object", (str o deresolve) co,

                    str "extends", applify "[" "]" I NOBR ((str o deresolve) name)

                      (replicate (length vs) (str "Nothing"))]

              | print_co ((co, vs_args), tys) =

                  concat [applify "(" ")"

                    (fn (v, arg) => constraint (str v) (print_typ tyvars NOBR arg)) NOBR

                    (applify "[" "]" (str o lookup_tyvar tyvars) NOBR ((concat o map str)

                      ["final", "case", "class", deresolve co]) vs_args)

                    (Name.names (snd reserved) "a" tys),

                    str "extends",

                    applify "[" "]" (str o lookup_tyvar tyvars o fst) NOBR

                      ((str o deresolve) name) vs

                  ];

          in

            Pretty.chunks (applify "[" "]" (str o prefix "+" o lookup_tyvar tyvars o fst)

              NOBR ((concat o map str) ["abstract", "sealed", "class", deresolve name]) vs

                :: map print_co cos)

          end

      | print_stmt (name, Code_Thingol.Class (_, (v, (super_classes, classparams)))) =

          let

            val tyvars = intro_tyvars [(v, [name])] reserved;

            fun add_typarg s = Pretty.block

              [str s, str "[", (str o lookup_tyvar tyvars) v, str "]"];

            fun print_super_classes [] = NONE

              | print_super_classes classes = SOME (concat (str "extends"

                  :: separate (str "with") (map (add_typarg o deresolve o fst) classes)));

            fun print_classparam_val (classparam, ty) =

              concat [str "val", constraint (print_method classparam)

                ((print_tupled_typ tyvars o Code_Thingol.unfold_fun) ty)];

            fun print_classparam_def (classparam, ty) =

              let

                val (tys, ty) = Code_Thingol.unfold_fun ty;

                val [implicit_name] = Name.invents (snd reserved) (lookup_tyvar tyvars v) 1;

                val proto_vars = intro_vars [implicit_name] reserved;

                val auxs = Name.invents (snd proto_vars) "a" (length tys);

                val vars = intro_vars auxs proto_vars;

              in

                concat [str "def", constraint (Pretty.block [applify "(" ")"

                  (fn (aux, ty) => constraint ((str o lookup_var vars) aux)

                  (print_typ tyvars NOBR ty)) NOBR (add_typarg (deresolve classparam))

                  (auxs ~~ tys), str "(implicit ", str implicit_name, str ": ",

                  add_typarg (deresolve name), str ")"]) (print_typ tyvars NOBR ty), str "=",

                  applify "(" ")" (str o lookup_var vars) NOBR

                  (Pretty.block [str implicit_name, str ".", print_method classparam]) auxs]

              end;

          in

            Pretty.chunks (

              (Pretty.block_enclose

                (concat ([str "trait", (add_typarg o deresolve) name]

                  @ the_list (print_super_classes super_classes) @ [str "{"]), str "}")

                (map print_classparam_val classparams))

              :: map print_classparam_def classparams

            )

          end

      | print_stmt (name, Code_Thingol.Classinst ((class, (tyco, vs)),

            (super_instances, (classparam_instances, further_classparam_instances)))) =

          let

            val tyvars = intro_tyvars vs reserved;

            val classtyp = (class, tyco `%% map (ITyVar o fst) vs);

            fun print_classparam_instance ((classparam, const as (_, (_, tys))), (thm, _)) =

              let

                val aux_tys = Name.names (snd reserved) "a" tys;

                val auxs = map fst aux_tys;

                val vars = intro_vars auxs reserved;

                val aux_abstr = if null auxs then [] else [enum "," "(" ")"

                  (map (fn (aux, ty) => constraint ((str o lookup_var vars) aux)

                  (print_typ tyvars NOBR ty)) aux_tys), str "=>"];

              in 

                concat ([str "val", print_method classparam, str "="]

                  @ aux_abstr @| print_app tyvars false (SOME thm) vars NOBR

                    (const, map (IVar o SOME) auxs))

              end;

          in

            Pretty.block_enclose (concat [str "implicit def",

              constraint (print_context tyvars vs name) (print_dicttyp tyvars classtyp),

              str "=", str "new", print_dicttyp tyvars classtyp, str "{"], str "}")

                (map print_classparam_instance (classparam_instances @ further_classparam_instances))

          end;

  in print_stmt end;

local

(* hierarchical module name space *)

datatype node =

    Dummy

  | Stmt of Code_Thingol.stmt

  | Module of (string list * (string * node) Graph.T);

in

fun scala_program_of_program labelled_name reserved module_alias program =

  let

    (* building module name hierarchy *)

    fun alias_fragments name = case module_alias name

     of SOME name' => Long_Name.explode name'

      | NONE => map (fn name => fst (yield_singleton Name.variants name reserved))

          (Long_Name.explode name);

    val module_names = Graph.fold (insert (op =) o fst o dest_name o fst) program [];

    val fragments_tab = fold (fn name => Symtab.update

      (name, alias_fragments name)) module_names Symtab.empty;

    val dest_name = Code_Printer.dest_name #>> (the o Symtab.lookup fragments_tab);

    (* building empty module hierarchy *)

    val empty_module = ([], Graph.empty);

    fun map_module f (Module content) = Module (f content);

    fun change_module [] = I

      | change_module (name_fragment :: name_fragments) =

          apsnd o Graph.map_node name_fragment o apsnd o map_module

            o change_module name_fragments;

    fun ensure_module name_fragment (implicits, nodes) =

      if can (Graph.get_node nodes) name_fragment then (implicits, nodes)

      else (implicits,

        nodes |> Graph.new_node (name_fragment, (name_fragment, Module empty_module)));

    fun allocate_module [] = I

      | allocate_module (name_fragment :: name_fragments) =

          ensure_module name_fragment

          #> (apsnd o Graph.map_node name_fragment o apsnd o map_module o allocate_module) name_fragments;

    val empty_program = Symtab.fold (fn (_, fragments) => allocate_module fragments)

      fragments_tab empty_module;

    (* distribute statements over hierarchy *)

    fun add_stmt name stmt =

      let

        val (name_fragments, base) = dest_name name;

        fun is_classinst stmt = case stmt

         of Code_Thingol.Classinst _ => true

          | _ => false;

        val implicit_deps = filter (is_classinst o Graph.get_node program)

          (Graph.imm_succs program name);

      in

        change_module name_fragments (fn (implicits, nodes) =>

          (union (op =) implicit_deps implicits, Graph.new_node (name, (base, Stmt stmt)) nodes))

      end;

    fun add_dependency name name' =

      let

        val (name_fragments, base) = dest_name name;

        val (name_fragments', base') = dest_name name';

        val (name_fragments_common, (diff, diff')) =

          chop_prefix (op =) (name_fragments, name_fragments');

        val dep = if null diff then (name, name') else (hd diff, hd diff')

      in (change_module name_fragments_common o apsnd) (Graph.add_edge dep) end;

    val proto_program = empty_program

      |> Graph.fold (fn (name, (stmt, _)) => add_stmt name stmt) program

      |> Graph.fold (fn (name, (_, (_, names))) => fold (add_dependency name) names) program;

    (* name declarations *)

    fun namify_module name_fragment ((nsp_class, nsp_object), nsp_common) =

      let

        val declare = Name.declare name_fragment;

      in (name_fragment, ((declare nsp_class, declare nsp_object), declare nsp_common)) end;

    fun namify_class base ((nsp_class, nsp_object), nsp_common) =

      let

        val (base', nsp_class') = yield_singleton Name.variants base nsp_class

      in (base', ((nsp_class', nsp_object), Name.declare base' nsp_common)) end;

    fun namify_object base ((nsp_class, nsp_object), nsp_common) =

      let

        val (base', nsp_object') = yield_singleton Name.variants base nsp_object

      in (base', ((nsp_class, nsp_object'), Name.declare base' nsp_common)) end;

    fun namify_common upper base ((nsp_class, nsp_object), nsp_common) =

      let

        val (base', nsp_common') =

          yield_singleton Name.variants (if upper then first_upper base else base) nsp_common

      in

        (base',

          ((Name.declare base' nsp_class, Name.declare base' nsp_object), nsp_common'))

      end;

    fun namify_stmt (Code_Thingol.Fun _) = namify_object

      | namify_stmt (Code_Thingol.Datatype _) = namify_class

      | namify_stmt (Code_Thingol.Datatypecons _) = namify_common true

      | namify_stmt (Code_Thingol.Class _) = namify_class

      | namify_stmt (Code_Thingol.Classrel _) = namify_object

      | namify_stmt (Code_Thingol.Classparam _) = namify_object

      | namify_stmt (Code_Thingol.Classinst _) = namify_common false;

    fun make_declarations nsps (implicits, nodes) =

      let

        val (module_fragments, stmt_names) = List.partition

          (fn name_fragment => case Graph.get_node nodes name_fragment

            of (_, Module _) => true | _ => false) (Graph.keys nodes);

        fun modify_stmt (Stmt (Code_Thingol.Datatypecons _)) = Dummy

          | modify_stmt (Stmt (Code_Thingol.Classrel _)) = Dummy

          | modify_stmt (Stmt (Code_Thingol.Classparam _)) = Dummy

          | modify_stmt stmt = stmt;

        fun declare namify modify name (nsps, nodes) =

          let

            val (base, node) = Graph.get_node nodes name;

            val (base', nsps') = namify node base nsps;

            val nodes' = Graph.map_node name (K (base', modify node)) nodes;

          in (nsps', nodes') end;

        val (nsps', nodes') = (nsps, nodes)

          |> fold (declare (K namify_module) I) module_fragments

          |> fold (declare (namify_stmt o (fn Stmt stmt => stmt)) modify_stmt) stmt_names;

        val nodes'' = nodes'

          |> fold (fn name_fragment => (Graph.map_node name_fragment

              o apsnd o map_module) (make_declarations nsps')) module_fragments;

      in (implicits, nodes'') end;

    val (_, sca_program) = make_declarations ((reserved, reserved), reserved) proto_program;

    (* deresolving *)

    fun deresolver prefix_fragments name =

      let

        val (name_fragments, _) = dest_name name;

        val (_, (_, remainder)) = chop_prefix (op =) (prefix_fragments, name_fragments);

        val nodes = fold (fn name_fragment => fn nodes => case Graph.get_node nodes name_fragment

         of (_, Module (_, nodes)) => nodes) name_fragments sca_program;

        val (base', _) = Graph.get_node nodes name;

      in Long_Name.implode (remainder @ [base']) end

        handle Graph.UNDEF _ => error ("Unknown statement name: " ^ labelled_name name);

  in (deresolver, sca_program) end;

fun serialize_scala labelled_name raw_reserved includes module_alias

    _ syntax_tyco syntax_const (code_of_pretty, code_writeln)

    program (stmt_names, presentation_stmt_names) destination =

  let

    (* build program *)

    val reserved = fold (insert (op =) o fst) includes raw_reserved;

    val (deresolver, sca_program) = scala_program_of_program labelled_name

      (Name.make_context reserved) module_alias program;

    (* print statements *)

    fun lookup_constr tyco constr = case Graph.get_node program tyco

     of Code_Thingol.Datatype (_, (_, constrs)) =>

          the (AList.lookup (op = o apsnd fst) constrs constr);

    fun classparams_of_class class = case Graph.get_node program class

     of Code_Thingol.Class (_, (_, (_, classparams))) => classparams;

    fun args_num c = case Graph.get_node program c

     of Code_Thingol.Fun (_, (((_, ty), []), _)) =>

          (length o fst o Code_Thingol.unfold_fun) ty

      | Code_Thingol.Fun (_, ((_, ((ts, _), _) :: _), _)) => length ts

      | Code_Thingol.Datatypecons (_, tyco) => length (lookup_constr tyco c)

      | Code_Thingol.Classparam (_, class) =>

          (length o fst o Code_Thingol.unfold_fun o the o AList.lookup (op =)

            (classparams_of_class class)) c;

    fun is_singleton_constr c = case Graph.get_node program c

     of Code_Thingol.Datatypecons (_, tyco) => null (lookup_constr tyco c)

      | _ => false;

    val print_stmt = print_scala_stmt labelled_name syntax_tyco syntax_const

      (make_vars reserved) args_num is_singleton_constr;

    (* print nodes *)

    fun print_module base implicit_ps p = Pretty.chunks2

      ([str ("object " ^ base ^ " {")]

        @ (if null implicit_ps then [] else (single o Pretty.block)

            (str "import /*implicits*/" :: Pretty.brk 1 :: commas implicit_ps))

        @ [p, str ("} /* object " ^ base ^ " */")]);

    fun print_implicit prefix_fragments implicit =

      let

        val s = deresolver prefix_fragments implicit;

      in if length (Long_Name.explode s) = 1 then NONE else SOME (str s) end;

    fun print_node _ (_, Dummy) = NONE

      | print_node prefix_fragments (name, Stmt stmt) =

          if null presentation_stmt_names

          orelse member (op =) presentation_stmt_names name

          then SOME (print_stmt (deresolver prefix_fragments, deresolver []) (name, stmt))

          else NONE

      | print_node prefix_fragments (name_fragment, Module (implicits, nodes)) =

          if null presentation_stmt_names

          then

            let

              val prefix_fragments' = prefix_fragments @ [name_fragment];

            in

              Option.map (print_module name_fragment

                (map_filter (print_implicit prefix_fragments') implicits))

                  (print_nodes prefix_fragments' nodes)

            end

          else print_nodes [] nodes

    and print_nodes prefix_fragments nodes = let

        val ps = map_filter (fn name => print_node prefix_fragments (name,

          snd (Graph.get_node nodes name)))

            ((rev o flat o Graph.strong_conn) nodes);

      in if null ps then NONE else SOME (Pretty.chunks2 ps) end;

    (* serialization *)

    val p_includes = if null presentation_stmt_names

      then map (fn (base, p) => print_module base [] p) includes else [];

    val p = Pretty.chunks2 (p_includes @ the_list (print_nodes [] sca_program));

  in

    Code_Target.mk_serialization target

      (fn NONE => code_writeln | SOME file => File.write file o code_of_pretty)

      (rpair [] o code_of_pretty) p destination

  end;

end; (*local*)

val literals = let

  fun char_scala c = if c = "'" then "\\'"

    else if c = "\"" then "\\\""

    else if c = "\\" then "\\\\"

    else let val k = ord c

    in if k < 32 orelse k > 126 then "\\" ^ radixstring (8, "0", k) else c end

  fun numeral_scala k = if k < 0

    then if k > ~ 2147483647 then "- " ^ string_of_int (~ k)

      else quote ("- " ^ string_of_int (~ k))

    else if k <= 2147483647 then string_of_int k

      else quote (string_of_int k)

in Literals {

  literal_char = Library.enclose "'" "'" o char_scala,

  literal_string = quote o translate_string char_scala,

  literal_numeral = fn k => "BigInt(" ^ numeral_scala k ^ ")",

  literal_positive_numeral = fn k => "Nat.Nat(" ^ numeral_scala k ^ ")",

  literal_alternative_numeral = fn k => "Natural.Nat(" ^ numeral_scala k ^ ")",

  literal_naive_numeral = fn k => "BigInt(" ^ numeral_scala k ^ ")",

  literal_list = fn [] => str "Nil" | ps => Pretty.block [str "List", enum "," "(" ")" ps],

  infix_cons = (6, "::")

} end;

(** Isar setup **)

fun isar_serializer _ =

  Code_Target.parse_args (Scan.succeed ())

  #> (fn () => serialize_scala);

val setup =

  Code_Target.add_target

    (target, { serializer = isar_serializer, literals = literals,

      check = { env_var = "SCALA_HOME", make_destination = fn p => Path.append p (Path.explode "ROOT.scala"),

        make_command = fn scala_home => fn _ =>

          "export JAVA_OPTS='-Xms128m -Xmx512m -Xss2m' && "

            ^ Path.implode (Path.append (Path.explode scala_home) (Path.explode "bin/scalac")) ^ " ROOT.scala" } })

  #> Code_Target.add_syntax_tyco target "fun"

     (SOME (2, fn print_typ => fn fxy => fn [ty1, ty2] =>

        brackify_infix (1, R) fxy (

          print_typ BR ty1 (*product type vs. tupled arguments!*),

          str "=>",

          print_typ (INFX (1, R)) ty2

        )))

  #> fold (Code_Target.add_reserved target) [

      "abstract", "case", "catch", "class", "def", "do", "else", "extends", "false",

      "final", "finally", "for", "forSome", "if", "implicit", "import", "lazy",

      "match", "new", "null", "object", "override", "package", "private", "protected",

      "requires", "return", "sealed", "super", "this", "throw", "trait", "try",

      "true", "type", "val", "var", "while", "with", "yield"

    ]

  #> fold (Code_Target.add_reserved target) [

      "apply", "error", "BigInt", "Nil", "List"

    ];

end; (*struct*)