(*  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 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 string_of_pretty: int -> Pretty.T -> string

  val writeln_pretty: int -> Pretty.T -> unit

  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_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_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 -> fixity -> Pretty.T -> Pretty.T list -> Pretty.T

  type tyco_syntax

  type simple_const_syntax

  type proto_const_syntax

  type const_syntax

  val parse_infix: ('a -> 'b) -> lrx * int -> string

    -> int * ((fixity -> 'b -> Pretty.T)

    -> fixity -> 'a list -> Pretty.T)

  val parse_syntax: ('a -> 'b) -> Token.T list

    -> (int * ((fixity -> 'b -> Pretty.T)

    -> fixity -> 'a list -> Pretty.T)) option * Token.T list

  val simple_const_syntax: simple_const_syntax -> proto_const_syntax

  val activate_const_syntax: theory -> literals

    -> proto_const_syntax -> Code_Thingol.naming -> 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 -> 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

  val mk_name_module: Name.context -> string option -> (string -> string option)

    -> 'a Graph.T -> string -> string

  val dest_name: string -> string * string

end;

structure Code_Printer : CODE_PRINTER =

struct

open Code_Thingol;

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

  | eqn_error NONE s = error s;

(** 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;

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 string_of_pretty width p = Print_Mode.setmp [] (Pretty.string_of_margin width) p ^ "\n";

fun writeln_pretty width p = writeln (Print_Mode.setmp [] (Pretty.string_of_margin width) p);

(** 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_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_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 fxy_ctxt p [] = p

  | applify opn cls fxy_ctxt p ps =

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

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

(* 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 proto_const_syntax = int * (string list * (literals -> string list

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

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

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

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

fun simple_const_syntax syn =

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

fun activate_const_syntax thy literals (n, (cs, f)) naming =

  fold_map (Code_Thingol.ensure_declared_const thy) cs naming

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

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

  case syntax_const c

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

    | SOME (k, print) =>

        let

          fun print' fxy ts = print (print_term thm) 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 thm vars BR) ts2)

          else print_term 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

  | Pretty of Pretty.T;

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 (Pretty p :: mfx) args =

          p :: 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, (Pretty o str) " ", (Pretty o str) s, (Pretty o Pretty.brk) 1, Arg r])

  end;

fun parse_mixfix 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))

      || ($$ "/" |-- Scan.repeat ($$ " ") >> (Pretty o Pretty.brk o length))

      || (Scan.repeat1

           (   $$ "'" |-- sym_any

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

                 sym_any) >> (Pretty o str o implode)));

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

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

    | ((b, p as _ :: _ :: _), []) => 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 prep_arg xs =

  Scan.option ((

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

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

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

        -- Parse.nat >> parse_infix prep_arg

      || Scan.succeed (parse_mixfix prep_arg))

      -- Parse.string

      >> (fn (parse, s) => parse s)) xs;

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

(** module name spaces **)

val dest_name =

  apfst Long_Name.implode o split_last o fst o split_last o Long_Name.explode;

fun mk_name_module reserved module_prefix module_alias program =

  let

    fun mk_alias name = case module_alias name

     of SOME name' => name'

      | NONE => name

          |> Long_Name.explode

          |> map (fn name => (the_single o fst) (Name.variants [name] reserved))

          |> Long_Name.implode;

    fun mk_prefix name = case module_prefix

     of SOME module_prefix => Long_Name.append module_prefix name

      | NONE => name;

    val tab =

      Symtab.empty

      |> Graph.fold ((fn name => Symtab.default (name, (mk_alias #> mk_prefix) name))

           o fst o dest_name o fst)

             program

  in the o Symtab.lookup tab end;

end; (*struct*)