(*  Title:      Tools/Code/code_scala.ML

    Author:     Florian Haftmann, TU Muenchen

Serializer for Scala.

*)

signature CODE_SCALA =

sig

  val target: string

  val check: theory -> Path.T -> unit

  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 =

  let

    val deresolve_base = Long_Name.base_name o deresolve;

    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 l = case syntax_const c of NONE => args_num c | SOME (l, _) => l;

        val arg_typs' = if is_pat orelse

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

        val (no_syntax, print') = case syntax_const c

         of NONE => (true, 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 (_, print) => (false, fn ts =>

              print (print_term tyvars is_pat some_thm) some_thm vars fxy

                (ts ~~ take l function_typs));

      in if k = l then print' 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' 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 ((pat, ty), t) vars =

              vars

              |> print_bind tyvars some_thm BR pat

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

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

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

            val (ps, p) = split_last all_ps;

          in brackify_block fxy

            (str "{")

            (ps @ Pretty.block [p, str ";"] @@ print_term tyvars false some_thm vars' NOBR body)

            (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 deresolve_base);

    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_base) co,

                    str "extends", applify "[" "]" I NOBR ((str o deresolve_base) 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_base co]) vs_args)

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

                    str "extends",

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

                      ((str o deresolve_base) name) vs

                  ];

          in

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

              NOBR ((concat o map str) ["sealed", "class", deresolve_base 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_base) 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;

fun scala_program_of_program labelled_name module_name reserved raw_module_alias program =

  let

    val the_module_name = the_default "Program" module_name;

    val module_alias = K (SOME the_module_name);

    val reserved = Name.make_context reserved;

    fun prepare_stmt (name, stmt) (nsps, stmts) =

      let

        val (_, base) = Code_Printer.dest_name name;

        val mk_name_stmt = yield_singleton Name.variants;

        fun add_class ((nsp_class, nsp_object), nsp_common) =

          let

            val (base', nsp_class') = mk_name_stmt base nsp_class

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

        fun add_object ((nsp_class, nsp_object), nsp_common) =

          let

            val (base', nsp_object') = mk_name_stmt base nsp_object

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

        fun add_common upper ((nsp_class, nsp_object), nsp_common) =

          let

            val (base', nsp_common') =

              mk_name_stmt (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;

        val add_name = case stmt

         of Code_Thingol.Fun _ => add_object

          | Code_Thingol.Datatype _ => add_class

          | Code_Thingol.Datatypecons _ => add_common true

          | Code_Thingol.Class _ => add_class

          | Code_Thingol.Classrel _ => add_object

          | Code_Thingol.Classparam _ => add_object

          | Code_Thingol.Classinst _ => add_common false;

        fun add_stmt base' = case stmt

         of Code_Thingol.Datatypecons _ => cons (name, (base', NONE))

          | Code_Thingol.Classrel _ => cons (name, (base', NONE))

          | Code_Thingol.Classparam _ => cons (name, (base', NONE))

          | _ => cons (name, (base', SOME stmt));

      in

        nsps

        |> add_name

        |-> (fn base' => rpair (add_stmt base' stmts))

      end;

    val stmts = AList.make (Graph.get_node program) (Graph.strong_conn program |> flat)

      |> filter_out (Code_Thingol.is_case o snd);

    val (_, sca_program) = fold prepare_stmt stmts (((reserved, reserved), reserved), []);

    fun deresolver name = (fst o the o AList.lookup (op =) sca_program) name

      handle Option => error ("Unknown statement name: " ^ labelled_name name);

  in (deresolver, (the_module_name, sca_program)) end;

fun serialize_scala raw_module_name labelled_name

    raw_reserved includes raw_module_alias

    _ syntax_tyco syntax_const (code_of_pretty, code_writeln)

    program stmt_names destination =

  let

    val presentation_stmt_names = Code_Target.stmt_names_of_destination destination;

    val module_name = if null presentation_stmt_names then raw_module_name else SOME "Code";

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

    val (deresolver, (the_module_name, sca_program)) = scala_program_of_program labelled_name

      module_name reserved raw_module_alias program;

    val reserved = make_vars reserved;

    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

      reserved args_num is_singleton_constr deresolver;

    fun print_module name content =

      (name, Pretty.chunks [

        str ("object " ^ name ^ " {"),

        str "",

        content,

        str "",

        str "}"

      ]);

    fun serialize_module the_module_name sca_program =

      let

        val content = Pretty.chunks2 (map_filter

          (fn (name, (_, SOME stmt)) => SOME (print_stmt (name, stmt))

            | (_, (_, NONE)) => NONE) sca_program);

      in print_module the_module_name content end;

    fun check_destination destination =

      (File.check destination; destination);

    fun write_module destination (modlname, content) =

      let

        val filename = case modlname

         of "" => Path.explode "Main.scala"

          | _ => (Path.ext "scala" o Path.explode o implode o separate "/"

                o Long_Name.explode) modlname;

        val pathname = Path.append destination filename;

        val _ = File.mkdir_leaf (Path.dir pathname);

      in File.write pathname (code_of_pretty content) end

  in

    Code_Target.mk_serialization target

      (fn NONE => K () o map (code_writeln o snd) | SOME file => K () o map

        (write_module (check_destination file)))

      (rpair [] o cat_lines o map (code_of_pretty o snd))

      (map (uncurry print_module) includes

        @| serialize_module the_module_name sca_program)

      destination

  end;

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_naive_numeral = fn k => if k >= 0

    then string_of_int k else "(- " ^ string_of_int (~ k) ^ ")",

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

  infix_cons = (6, "::")

} end;

(** formal checking of compiled code **)

fun check thy = Code_Target.external_check thy target

  "SCALA_HOME" I (fn scala_home => fn p => fn _ =>

    Path.implode (Path.append (Path.explode scala_home) (Path.explode "bin/scalac")) ^ " *.scala");

(** Isar setup **)

fun isar_seri_scala module_name =

  Code_Target.parse_args (Scan.succeed ())

  #> (fn () => serialize_scala module_name);

val setup =

  Code_Target.add_target (target, (isar_seri_scala, literals))

  #> 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*)