(*  Title:      Tools/Code/code_printer.ML

     Author:     Florian Haftmann, TU Muenchen

 Generic operations for pretty printing of target language code.

 *)

 signature CODE_PRINTER =

 sig

   type itype = Code_Thingol.itype

   type iterm = Code_Thingol.iterm

   type const = Code_Thingol.const

   type dict = Code_Thingol.dict

   val eqn_error: thm option -> string -> 'a

   val @@ : 'a * 'a -> 'a list

   val @| : 'a list * 'a -> 'a list

   val str: string -> Pretty.T

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

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

   val enclose: string -> string -> Pretty.T list -> Pretty.T

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

   val enum: string -> string -> string -> Pretty.T list -> Pretty.T

   val enum_default: string -> string -> string -> string -> Pretty.T list -> Pretty.T

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

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

   val indent: int -> Pretty.T -> Pretty.T

   val markup_stmt: string -> Pretty.T -> Pretty.T

   val format: string list -> int -> Pretty.T -> string

   val first_upper: string -> string

   val first_lower: string -> string

   type var_ctxt

   val make_vars: string list -> var_ctxt

   val intro_vars: string list -> var_ctxt -> var_ctxt

   val lookup_var: var_ctxt -> string -> string

   val intro_base_names: (string -> bool) -> (string -> string)

     -> string list -> var_ctxt -> var_ctxt

   val aux_params: var_ctxt -> iterm list list -> string list

   type literals

   val Literals: { literal_char: string -> string, literal_string: string -> string,

         literal_numeral: int -> string,

         literal_positive_numeral: int -> string,

         literal_alternative_numeral: int -> string,

         literal_naive_numeral: int -> string,

         literal_list: Pretty.T list -> Pretty.T, infix_cons: int * string }

     -> literals

   val literal_char: literals -> string -> string

   val literal_string: literals -> string -> string

   val literal_numeral: literals -> int -> string

   val literal_positive_numeral: literals -> int -> string

   val literal_alternative_numeral: literals -> int -> string

   val literal_naive_numeral: literals -> int -> string

   val literal_list: literals -> Pretty.T list -> Pretty.T

   val infix_cons: literals -> int * string

   type lrx

   val L: lrx

   val R: lrx

   val X: lrx

   type fixity

   val BR: fixity

   val NOBR: fixity

   val INFX: int * lrx -> fixity

   val APP: fixity

   val brackify: fixity -> Pretty.T list -> Pretty.T

   val brackify_infix: int * lrx -> fixity -> Pretty.T * Pretty.T * Pretty.T -> Pretty.T

   val brackify_block: fixity -> Pretty.T -> Pretty.T list -> Pretty.T -> Pretty.T

   val applify: string -> string -> ('a -> Pretty.T) -> fixity -> Pretty.T -> 'a list -> Pretty.T

   val tuplify: (fixity -> 'a -> Pretty.T) -> fixity -> 'a list -> Pretty.T option

   type tyco_syntax

   type simple_const_syntax

   type complex_const_syntax

   type const_syntax

   type activated_complex_const_syntax

   datatype activated_const_syntax = Plain_const_syntax of int * string

     | Complex_const_syntax of activated_complex_const_syntax

   val requires_args: const_syntax -> int

   val parse_const_syntax: Token.T list -> const_syntax option * Token.T list

   val parse_tyco_syntax: Token.T list -> tyco_syntax option * Token.T list

   val plain_const_syntax: string -> const_syntax

   val simple_const_syntax: simple_const_syntax -> const_syntax

   val complex_const_syntax: complex_const_syntax -> const_syntax

   val activate_const_syntax: theory -> literals

     -> string -> const_syntax -> Code_Thingol.naming -> activated_const_syntax * Code_Thingol.naming

   val gen_print_app: (thm option -> var_ctxt -> const * iterm list -> Pretty.T list)

     -> (thm option -> var_ctxt -> fixity -> iterm -> Pretty.T)

     -> (string -> activated_const_syntax option)

     -> thm option -> var_ctxt -> fixity -> const * iterm list -> Pretty.T

   val gen_print_bind: (thm option -> var_ctxt -> fixity -> iterm -> Pretty.T)

     -> thm option -> fixity

     -> iterm -> var_ctxt -> Pretty.T * var_ctxt

 end;

 structure Code_Printer : CODE_PRINTER =

 struct

 open Code_Thingol;

 (** generic nonsense *)

 fun eqn_error (SOME thm) s = error (s ^ ",\nin equation " ^ Display.string_of_thm_without_context thm)

   | eqn_error NONE s = error s;

 val code_presentationN = "code_presentation";

 val stmt_nameN = "stmt_name";

 val _ = Markup.add_mode code_presentationN YXML.output_markup;

 (** assembling and printing text pieces **)

 infixr 5 @@;

 infixr 5 @|;

 fun x @@ y = [x, y];

 fun xs @| y = xs @ [y];

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

 val concat = Pretty.block o Pretty.breaks;

 val commas = Print_Mode.setmp [] Pretty.commas;

 fun enclose l r = Print_Mode.setmp [] (Pretty.enclose l r);

 val brackets = enclose "(" ")" o Pretty.breaks;

 fun enum sep l r = Print_Mode.setmp [] (Pretty.enum sep l r);

 fun enum_default default sep l r [] = str default

   | enum_default default sep l r xs = enum sep l r xs;

 fun semicolon ps = Pretty.block [concat ps, str ";"];

 fun doublesemicolon ps = Pretty.block [concat ps, str ";;"];

 fun indent i = Print_Mode.setmp [] (Pretty.indent i);

 fun markup_stmt name = Print_Mode.setmp [code_presentationN]

   (Pretty.mark (code_presentationN, [(stmt_nameN, name)]));

 fun filter_presentation presentation_names selected (XML.Elem ((name, attrs), xs)) =

       implode (map (filter_presentation presentation_names

         (selected orelse (name = code_presentationN

           andalso member (op =) presentation_names (the (Properties.get attrs stmt_nameN))))) xs)

   | filter_presentation presentation_names selected (XML.Text s) =

       if selected then s else "";

 fun maps_string s f [] = ""

   | maps_string s f (x :: xs) =

       let

         val s1 = f x;

         val s2 = maps_string s f xs;

       in if s1 = "" then s2

         else if s2 = "" then s1

         else s1 ^ s ^ s2

       end;

 fun plain_text (XML.Elem (_, xs)) = implode (map plain_text xs)

   | plain_text (XML.Text s) = s

 fun format presentation_names width =

   Print_Mode.setmp [code_presentationN] (Pretty.string_of_margin width)

   #> YXML.parse_body

   #> (if null presentation_names then implode o map plain_text

       else maps_string "\n\n" (filter_presentation presentation_names false))

   #> suffix "\n";

 (** names and variable name contexts **)

 type var_ctxt = string Symtab.table * Name.context;

 fun make_vars names = (fold (fn name => Symtab.update_new (name, name)) names Symtab.empty,

   Name.make_context names);

 fun intro_vars names (namemap, namectxt) =

   let

     val (names', namectxt') = Name.variants names namectxt;

     val namemap' = fold2 (curry Symtab.update) names names' namemap;

   in (namemap', namectxt') end;

 fun lookup_var (namemap, _) name = case Symtab.lookup namemap name

  of SOME name' => name'

   | NONE => error ("Invalid name in context: " ^ quote name);

 val first_upper = implode o nth_map 0 Symbol.to_ascii_upper o explode;

 val first_lower = implode o nth_map 0 Symbol.to_ascii_lower o explode;

 fun aux_params vars lhss =

   let

     fun fish_param _ (w as SOME _) = w

       | fish_param (IVar (SOME v)) NONE = SOME v

       | fish_param _ NONE = NONE;

     fun fillup_param _ (_, SOME v) = v

       | fillup_param x (i, NONE) = x ^ string_of_int i;

     val fished1 = fold (map2 fish_param) lhss (replicate (length (hd lhss)) NONE);

     val x = Name.variant (map_filter I fished1) "x";

     val fished2 = map_index (fillup_param x) fished1;

     val (fished3, _) = Name.variants fished2 Name.context;

     val vars' = intro_vars fished3 vars;

   in map (lookup_var vars') fished3 end;

 fun intro_base_names no_syntax deresolve names = names 

   |> map_filter (fn name => if no_syntax name then

       let val name' = deresolve name in

         if Long_Name.is_qualified name' then NONE else SOME name'

       end else NONE)

   |> intro_vars;

 (** pretty literals **)

 datatype literals = Literals of {

   literal_char: string -> string,

   literal_string: string -> string,

   literal_numeral: int -> string,

   literal_positive_numeral: int -> string,

   literal_alternative_numeral: int -> string,

   literal_naive_numeral: int -> string,

   literal_list: Pretty.T list -> Pretty.T,

   infix_cons: int * string

 };

 fun dest_Literals (Literals lits) = lits;

 val literal_char = #literal_char o dest_Literals;

 val literal_string = #literal_string o dest_Literals;

 val literal_numeral = #literal_numeral o dest_Literals;

 val literal_positive_numeral = #literal_positive_numeral o dest_Literals;

 val literal_alternative_numeral = #literal_alternative_numeral o dest_Literals;

 val literal_naive_numeral = #literal_naive_numeral o dest_Literals;

 val literal_list = #literal_list o dest_Literals;

 val infix_cons = #infix_cons o dest_Literals;

 (** syntax printer **)

 (* binding priorities *)

 datatype lrx = L | R | X;

 datatype fixity =

     BR

   | NOBR

   | INFX of (int * lrx);

 val APP = INFX (~1, L);

 fun fixity_lrx L L = false

   | fixity_lrx R R = false

   | fixity_lrx _ _ = true;

 fun fixity NOBR _ = false

   | fixity _ NOBR = false

   | fixity (INFX (pr, lr)) (INFX (print_ctxt, lr_ctxt)) =

       pr < print_ctxt

       orelse pr = print_ctxt

         andalso fixity_lrx lr lr_ctxt

       orelse print_ctxt = ~1

   | fixity BR (INFX _) = false

   | fixity _ _ = true;

 fun gen_brackify _ [p] = p

   | gen_brackify true (ps as _::_) = enclose "(" ")" ps

   | gen_brackify false (ps as _::_) = Pretty.block ps;

 fun brackify fxy_ctxt =

   gen_brackify (fixity BR fxy_ctxt) o Pretty.breaks;

 fun brackify_infix infx fxy_ctxt (l, m, r) =

   (if fixity (INFX infx) fxy_ctxt then enclose "(" ")" else Pretty.block)

     ([l, str " ", m, Pretty.brk 1, r]);

 fun brackify_block fxy_ctxt p1 ps p2 =

   let val p = Pretty.block_enclose (p1, p2) ps

   in if fixity BR fxy_ctxt

     then enclose "(" ")" [p]

     else p

   end;

 fun applify opn cls f fxy_ctxt p [] = p

   | applify opn cls f fxy_ctxt p ps =

       (if (fixity BR fxy_ctxt) then enclose "(" ")" else Pretty.block)

         (p @@ enum "," opn cls (map f ps));

 fun tuplify _ _ [] = NONE

   | tuplify print fxy [x] = SOME (print fxy x)

   | tuplify print _ xs = SOME (enum "," "(" ")" (map (print NOBR) xs));

 (* generic syntax *)

 type tyco_syntax = int * ((fixity -> itype -> Pretty.T)

   -> fixity -> itype list -> Pretty.T);

 type simple_const_syntax = int * ((fixity -> iterm -> Pretty.T)

   -> fixity -> (iterm * itype) list -> Pretty.T);

 type complex_const_syntax = int * (string list * (literals -> string list

   -> (var_ctxt -> fixity -> iterm -> Pretty.T)

     -> thm option -> var_ctxt -> fixity -> (iterm * itype) list -> Pretty.T));

 datatype const_syntax = plain_const_syntax of string

   | complex_const_syntax of complex_const_syntax;

 fun requires_args (plain_const_syntax _) = 0

   | requires_args (complex_const_syntax (k, _)) = k;

 fun simple_const_syntax syn =

   complex_const_syntax (apsnd (fn f => ([], (fn _ => fn _ => fn print => fn _ => fn vars => f (print vars)))) syn);

 type activated_complex_const_syntax = int * ((var_ctxt -> fixity -> iterm -> Pretty.T)

   -> thm option -> var_ctxt -> fixity -> (iterm * itype) list -> Pretty.T)

 datatype activated_const_syntax = Plain_const_syntax of int * string

   | Complex_const_syntax of activated_complex_const_syntax;

 fun activate_const_syntax thy literals c (plain_const_syntax s) naming =

       (Plain_const_syntax (Code.args_number thy c, s), naming)

   | activate_const_syntax thy literals c (complex_const_syntax (n, (cs, f))) naming =

       fold_map (Code_Thingol.ensure_declared_const thy) cs naming

       |-> (fn cs' => pair (Complex_const_syntax (n, f literals cs')));

 fun gen_print_app print_app_expr print_term const_syntax some_thm vars fxy (app as ((c, (_, function_typs)), ts)) =

   case const_syntax c

    of NONE => brackify fxy (print_app_expr some_thm vars app)

     | SOME (Plain_const_syntax (_, s)) => brackify fxy (str s :: map (print_term some_thm vars BR) ts)

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

         let

           fun print' fxy ts = print (print_term some_thm) some_thm vars fxy (ts ~~ take k function_typs);

         in if k = length ts

           then print' fxy ts

         else if k < length ts

           then case chop k ts of (ts1, ts2) =>

             brackify fxy (print' APP ts1 :: map (print_term some_thm vars BR) ts2)

           else print_term some_thm vars fxy (Code_Thingol.eta_expand k app)

         end;

 fun gen_print_bind print_term thm (fxy : fixity) pat vars =

   let

     val vs = Code_Thingol.fold_varnames (insert (op =)) pat [];

     val vars' = intro_vars vs vars;

   in (print_term thm vars' fxy pat, vars') end;

 (* mixfix syntax *)

 datatype 'a mixfix =

     Arg of fixity

   | String of string

   | Break;

 fun mk_mixfix prep_arg (fixity_this, mfx) =

   let

     fun is_arg (Arg _) = true

       | is_arg _ = false;

     val i = (length o filter is_arg) mfx;

     fun fillin _ [] [] =

           []

       | fillin print (Arg fxy :: mfx) (a :: args) =

           (print fxy o prep_arg) a :: fillin print mfx args

       | fillin print (String s :: mfx) args =

           str s :: fillin print mfx args

       | fillin print (Break :: mfx) args =

           Pretty.brk 1 :: fillin print mfx args;

   in

     (i, fn print => fn fixity_ctxt => fn args =>

       gen_brackify (fixity fixity_this fixity_ctxt) (fillin print mfx args))

   end;

 fun parse_infix prep_arg (x, i) s =

   let

     val l = case x of L => INFX (i, L) | _ => INFX (i, X);

     val r = case x of R => INFX (i, R) | _ => INFX (i, X);

   in

     mk_mixfix prep_arg (INFX (i, x), [Arg l, String " ", String s, Break, Arg r])

   end;

 fun parse_mixfix mk_plain mk_complex prep_arg s =

   let

     val sym_any = Scan.one Symbol.is_regular;

     val parse = Scan.optional ($$ "!" >> K true) false -- Scan.repeat (

          ($$ "(" -- $$ "_" -- $$ ")" >> K (Arg NOBR))

       || ($$ "_" >> K (Arg BR))

       || ($$ "/" |-- Scan.repeat ($$ " ") >> (K Break))

       || (Scan.repeat1

            (   $$ "'" |-- sym_any

             || Scan.unless ($$ "_" || $$ "/" || $$ "(" |-- $$ "_" |-- $$ ")")

                  sym_any) >> (String o implode)));

   in case Scan.finite Symbol.stopper parse (Symbol.explode s)

    of ((false, [String s]), []) => mk_plain s

     | ((_, p as [_]), []) => mk_complex (mk_mixfix prep_arg (NOBR, p))

     | ((b, p as _ :: _ :: _), []) => mk_complex (mk_mixfix prep_arg (if b then NOBR else BR, p))

     | _ => Scan.!!

         (the_default ("malformed mixfix annotation: " ^ quote s) o snd) Scan.fail ()

   end;

 val (infixK, infixlK, infixrK) = ("infix", "infixl", "infixr");

 fun parse_syntax mk_plain mk_complex prep_arg =

   Scan.option (

       ((Parse.$$$ infixK >> K X)

         || (Parse.$$$ infixlK >> K L)

         || (Parse.$$$ infixrK >> K R))

         -- Parse.nat -- Parse.string

         >> (fn ((x, i), s) => mk_complex (parse_infix prep_arg (x, i) s))

       || Parse.string >> (fn s => (parse_mixfix mk_plain mk_complex prep_arg s)));

 val _ = List.app Keyword.keyword [infixK, infixlK, infixrK];

 fun parse_tyco_syntax x = parse_syntax (fn s => (0, (K o K o K o str) s)) I I x;

 val parse_const_syntax = parse_syntax plain_const_syntax simple_const_syntax fst;

 end; (*struct*)