(*  Author:     Florian Haftmann, TU Muenchen

 Serializer for Scala.

 *)

 signature CODE_SCALA =

 sig

   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 deresolve =

   let

     val deresolve_base = Long_Name.base_name o deresolve;

     fun print_typ tyvars fxy (tycoexpr as tyco `%% tys) = (case syntax_tyco tyco

          of NONE => applify "[" "]" fxy

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

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

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

     fun print_typed tyvars p ty =

       Pretty.block [p, str ":", Pretty.brk 1, print_typ tyvars NOBR ty]

     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 "(" ")" fxy

                 (print_term tyvars is_pat some_thm vars BR t1)

                 [print_term tyvars is_pat some_thm vars NOBR 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 [

               Pretty.block [str "(", print_typed tyvars (print_var vars' v) ty, str ")"],

               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, ((tys, _), tys_args)), ts)) =

       let

         val k = length ts;

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

         val tys' = if is_pat orelse

           (is_none (syntax_const c) andalso is_singleton c) then [] else tys;

         val (no_syntax, print') = case syntax_const c

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

               (applify "[" "]" NOBR ((str o deresolve) c) (map (print_typ tyvars NOBR) tys'))

                 (map (print_term tyvars is_pat some_thm vars NOBR) ts))

           | SOME (_, print) => (false, fn ts =>

               print (print_term tyvars is_pat some_thm) some_thm vars fxy (ts ~~ take l tys_args));

       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 => semicolon [Pretty.block [str "val", Pretty.brk 1, p,

                 str ":", Pretty.brk 1, print_typ tyvars NOBR ty],

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

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

           in

             brackify_block fxy

               (str "{")

               (ps @| 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, vars') = print_bind tyvars some_thm NOBR pat vars;

               in concat [str "case", p, str "=>", print_term tyvars false some_thm vars' NOBR 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 implicit_arguments tyvars vs vars =

       let

         val implicit_typ_ps = maps (fn (v, sort) => map (fn class => Pretty.block

           [(str o deresolve) class, str "[", (str o lookup_var tyvars) v, str "]"]) sort) vs;

         val implicit_names = Name.invents (snd vars) "a" (length implicit_typ_ps);

         val vars' = intro_vars implicit_names vars;

         val implicit_ps = map2 (fn v => fn p => concat [str (v ^ ":"), p])

           implicit_names implicit_typ_ps;

       in ((implicit_names, implicit_ps), vars') end;

     fun print_defhead tyvars vars p vs params tys implicits ty =

       concat [str "def", print_typed tyvars (applify "(implicit " ")" NOBR

         (applify "(" ")" NOBR

           (applify "[" "]" NOBR p (map (str o lookup_var tyvars o fst) vs))

             (map2 (fn param => fn ty => print_typed tyvars

                 ((str o lookup_var vars) param) ty)

               params tys)) implicits) ty, str "="]

     fun print_stmt (name, Code_Thingol.Fun (_, ((vs, ty), raw_eqs))) = (case filter (snd o snd) raw_eqs

          of [] =>

               let

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

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

                 val tyvars = intro_vars (map fst vs) reserved;

                 val vars = intro_vars params reserved;

               in

                 concat [print_defhead tyvars vars ((str o deresolve) name) vs params tys [] ty',

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

               end

           | 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_vars (map fst 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 ((_, implicit_ps), vars2) = implicit_arguments tyvars vs vars1;

                 val params = if simple then (map (fn IVar (SOME x) => x) o fst o fst o hd) eqs

                   else aux_params vars2 (map (fst o fst) eqs);

                 val vars3 = intro_vars params vars2;

                 val (tys, ty1) = Code_Thingol.unfold_fun ty;

                 val (tys1, tys2) = chop (length params) tys;

                 val ty2 = Library.foldr

                   (fn (ty1, ty2) => Code_Thingol.fun_tyco `%% [ty1, ty2]) (tys2, ty1);

                 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 []) vars2;

                   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 vars3 ((str o deresolve) name) vs params tys1 implicit_ps ty2;

               in if simple then

                 concat [head, print_rhs vars3 (hd eqs)]

               else

                 Pretty.block_enclose

                   (concat [head, print_tuple (map (str o lookup_var vars3) params),

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

                   (map print_clause eqs)

               end)

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

           let

             val tyvars = intro_vars (map fst vs) reserved;

             fun print_co (co, []) =

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

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

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

               | print_co (co, tys) =

                   let

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

                     val vars = intro_vars (map fst fields) reserved;

                     fun add_typargs p = applify "[" "]" NOBR p

                       (map (str o lookup_var tyvars o fst) vs);

                   in

                     concat [

                       applify "(" ")" NOBR

                         (add_typargs ((concat o map str) ["final", "case", "class", deresolve_base co]))

                         (map (uncurry (print_typed tyvars) o apfst str) fields),

                       str "extends",

                       add_typargs ((str o deresolve_base) name)

                     ]

                   end

           in

             Pretty.chunks (

               applify "[" "]" NOBR ((concat o map str) ["sealed", "class", deresolve_base name])

                 (map (str o prefix "+" o lookup_var tyvars o fst) vs)

               :: map print_co cos

             )

           end

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

           let

             val tyvars = intro_vars [v] reserved;

             val vs = [(v, [name])];

             fun add_typarg p = applify "[" "]" NOBR p [(str o lookup_var tyvars) v];

             fun print_superclasses [] = NONE

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

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

             fun print_tupled_typ ([], ty) =

                   print_typ tyvars NOBR ty

               | print_tupled_typ ([ty1], ty2) =

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

               | print_tupled_typ (tys, ty) =

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

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

             fun print_classparam_val (classparam, ty) =

               concat [str "val", (str o suffix "$:" o deresolve_base) classparam,

                 (print_tupled_typ o Code_Thingol.unfold_fun) ty]

             fun print_classparam_def (classparam, ty) =

               let

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

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

                 val vars = intro_vars params reserved;

                 val (([implicit], [p_implicit]), vars') = implicit_arguments tyvars vs vars;

                 val head = print_defhead tyvars vars' ((str o deresolve) classparam) vs params tys [p_implicit] ty;

               in

                 concat [head, applify "(" ")" NOBR

                   (Pretty.block [str implicit, str ".", (str o suffix "$" o deresolve_base) classparam])

                   (map (str o lookup_var vars') params)]

               end;

           in

             Pretty.chunks (

               (Pretty.block_enclose

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

                   @ the_list (print_superclasses superclasses) @ [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_insts))) =

           let

             val tyvars = intro_vars (map fst vs) reserved;

             val insttyp = tyco `%% map (ITyVar o fst) vs;

             val p_inst_typ = print_typ tyvars NOBR insttyp;

             fun add_typ_params p = applify "[" "]" NOBR p (map (str o lookup_var tyvars o fst) vs);

             fun add_inst_typ p = Pretty.block [p, str "[", p_inst_typ, str "]"];

             val ((implicit_names, implicit_ps), vars) = implicit_arguments tyvars vs reserved;

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

               let

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

                 val vars = intro_vars auxs reserved;

                 val args = if null auxs then [] else

                   [concat [enum "," "(" ")" (map2 (fn aux => fn ty => print_typed tyvars ((str o lookup_var vars) aux) ty)

                     auxs tys), str "=>"]];

               in 

                 concat ([str "val", (str o suffix "$" o deresolve_base) classparam,

                   str "="] @ args @ [print_app tyvars false (SOME thm) vars NOBR (const, map (IVar o SOME) auxs)])

               end;

           in

             Pretty.chunks [

               Pretty.block_enclose

                 (concat ([str "trait",

                     add_typ_params ((str o deresolve_base) name),

                     str "extends",

                     Pretty.block [(str o deresolve) class, str "[", p_inst_typ, str "]"]]

                     @ map (fn (_, (_, (superinst, _))) => add_typ_params (str ("with " ^ deresolve superinst)))

                       super_instances @| str "{"), str "}")

                 (map (fn p => Pretty.block [str "implicit val arg$", p]) implicit_ps

                   @ map print_classparam_inst classparam_insts),

               concat [str "implicit", str (if null vs then "val" else "def"),

                 applify "(implicit " ")" NOBR (applify "[" "]" NOBR

                   ((str o deresolve_base) name) (map (str o lookup_var tyvars o fst) vs))

                     implicit_ps,

                   str "=", str "new", applify "[" "]" NOBR ((str o deresolve_base) name)

                       (map (str o lookup_var tyvars o fst) vs),

                     Pretty.enum ";" "{ " " }" (map (str o (fn v => "val arg$" ^ v ^ " = " ^ v) o lookup_var vars)

                       implicit_names)]

             ]

           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 (_, sca_program) = fold prepare_stmt (AList.make (fn name => Graph.get_node program name)

       (Graph.strong_conn program |> flat)) (((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 cs destination =

   let

     val stmt_names = Code_Target.stmt_names_of_destination destination;

     val module_name = if null 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 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) =>

           let val Code_Thingol.Datatype (_, (_, constrs)) = Graph.get_node program tyco

           in (length o the o AList.lookup (op =) constrs) c end

       | Code_Thingol.Classparam (_, class) =>

           let val Code_Thingol.Class (_, (_, (_, classparams))) = Graph.get_node program class

           in (length o fst o Code_Thingol.unfold_fun o the o AList.lookup (op =) classparams) c end;

     fun is_singleton c = case Graph.get_node program c

      of Code_Thingol.Datatypecons (_, tyco) =>

           let val Code_Thingol.Datatype (_, (_, constrs)) = Graph.get_node program tyco

           in (null o the o AList.lookup (op =) constrs) c end

       | _ => false;

     val print_stmt = print_scala_stmt labelled_name syntax_tyco syntax_const

       reserved args_num is_singleton 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 (Path.dir pathname);

       in File.write pathname (code_of_pretty content) end

   in

     Code_Target.mk_serialization target NONE

       (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 =

     let

       val s = ML_Syntax.print_char c;

     in if s = "'" then "\\'" else s 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;

 (** 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"

     ]

   #> fold (Code_Target.add_reserved target) [

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

     ];

 end; (*struct*)