(*  Title:      Pure/Syntax/syn_ext.ML

    ID:         $Id$

    Author:     Markus Wenzel and Carsten Clasohm, TU Muenchen

    License:    GPL (GNU GENERAL PUBLIC LICENSE)

Syntax extension (internal interface).

*)

signature SYN_EXT0 =

sig

  val dddot_indexname: indexname

  val constrainC: string

  val typeT: typ

  val max_pri: int

end;

signature SYN_EXT =

sig

  include SYN_EXT0

  val logic: string

  val args: string

  val cargs: string

  val any: string

  val sprop: string

  val typ_to_nonterm: typ -> string

  datatype xsymb =

    Delim of string |

    Argument of string * int |

    Space of string |

    Bg of int | Brk of int | En

  datatype xprod = XProd of string * xsymb list * string * int

  val chain_pri: int

  val delims_of: xprod list -> string list list

  datatype mfix = Mfix of string * typ * string * int list * int

  datatype syn_ext =

    SynExt of {

      logtypes: string list,

      xprods: xprod list,

      consts: string list,

      prmodes: string list,

      parse_ast_translation: (string * (Ast.ast list -> Ast.ast)) list,

      parse_rules: (Ast.ast * Ast.ast) list,

      parse_translation: (string * (term list -> term)) list,

      print_translation: (string * (bool -> typ -> term list -> term)) list,

      print_rules: (Ast.ast * Ast.ast) list,

      print_ast_translation: (string * (Ast.ast list -> Ast.ast)) list,

      token_translation: (string * string * (string -> string * real)) list}

  val mfix_args: string -> int

  val escape_mfix: string -> string

  val mk_syn_ext: bool -> string list -> mfix list ->

    string list -> (string * (Ast.ast list -> Ast.ast)) list *

    (string * (term list -> term)) list *

    (string * (bool -> typ -> term list -> term)) list * (string * (Ast.ast list -> Ast.ast)) list

    -> (string * string * (string -> string * real)) list

    -> (Ast.ast * Ast.ast) list * (Ast.ast * Ast.ast) list -> syn_ext

  val syn_ext: string list -> mfix list -> string list ->

    (string * (Ast.ast list -> Ast.ast)) list * (string * (term list -> term)) list *

    (string * (bool -> typ -> term list -> term)) list * (string * (Ast.ast list -> Ast.ast)) list

    -> (string * string * (string -> string * real)) list

    -> (Ast.ast * Ast.ast) list * (Ast.ast * Ast.ast) list -> syn_ext

  val syn_ext_logtypes: string list -> syn_ext

  val syn_ext_const_names: string list -> string list -> syn_ext

  val syn_ext_rules: string list -> (Ast.ast * Ast.ast) list * (Ast.ast * Ast.ast) list -> syn_ext

  val syn_ext_trfuns: string list ->

    (string * (Ast.ast list -> Ast.ast)) list *

    (string * (term list -> term)) list *

    (string * (bool -> typ -> term list -> term)) list *

    (string * (Ast.ast list -> Ast.ast)) list -> syn_ext

  val syn_ext_tokentrfuns: string list

    -> (string * string * (string -> string * real)) list -> syn_ext

  val pure_ext: syn_ext

end;

structure SynExt : SYN_EXT =

struct

(** misc definitions **)

val dddot_indexname = ("dddot", 0);

val constrainC = "_constrain";

(* syntactic categories *)

val logic = "logic";

val logicT = Type (logic, []);

val args = "args";

val cargs = "cargs";

val typeT = Type ("type", []);

val sprop = "#prop";

val spropT = Type (sprop, []);

val any = "any";

val anyT = Type (any, []);

(** datatype xprod **)

(*Delim s: delimiter s

  Argument (s, p): nonterminal s requiring priority >= p, or valued token

  Space s: some white space for printing

  Bg, Brk, En: blocks and breaks for pretty printing*)

datatype xsymb =

  Delim of string |

  Argument of string * int |

  Space of string |

  Bg of int | Brk of int | En;

fun is_delim (Delim _) = true

  | is_delim _ = false;

fun is_terminal (Delim _) = true

  | is_terminal (Argument (s, _)) = Lexicon.is_terminal s

  | is_terminal _ = false;

fun is_argument (Argument _) = true

  | is_argument _ = false;

fun is_index (Argument ("index", _)) = true

  | is_index _ = false;

val index = Argument ("index", 1000);

(*XProd (lhs, syms, c, p):

    lhs: name of nonterminal on the lhs of the production

    syms: list of symbols on the rhs of the production

    c: head of parse tree

    p: priority of this production*)

datatype xprod = XProd of string * xsymb list * string * int;

val max_pri = 1000;   (*maximum legal priority*)

val chain_pri = ~1;   (*dummy for chain productions*)

(* delims_of *)

fun delims_of xprods =

  let

    fun del_of (Delim s) = Some s

      | del_of _ = None;

    fun dels_of (XProd (_, xsymbs, _, _)) =

      mapfilter del_of xsymbs;

  in

    map Symbol.explode (distinct (flat (map dels_of xprods)))

  end;

(** datatype mfix **)

(*Mfix (sy, ty, c, ps, p):

    sy: rhs of production as symbolic string

    ty: type description of production

    c: head of parse tree

    ps: priorities of arguments in sy

    p: priority of production*)

datatype mfix = Mfix of string * typ * string * int list * int;

fun err_in_mfix msg (Mfix (sy, _, const, _, _)) =

  error ((if msg = "" then "" else msg ^ "\n") ^

    "in mixfix annotation " ^ quote sy ^ " for " ^ quote const);

(* typ_to_nonterm *)

fun typ_to_nt _ (Type (c, _)) = c

  | typ_to_nt default _ = default;

(*get nonterminal for rhs*)

val typ_to_nonterm = typ_to_nt any;

(*get nonterminal for lhs*)

val typ_to_nonterm1 = typ_to_nt logic;

(* read_mixfix *)

local

  fun is_meta c = c mem ["(", ")", "/", "_", "\\<index>"];

  val scan_delim_char =

    $$ "'" |-- Scan.one ((not o Symbol.is_blank) andf Symbol.not_eof) ||

    Scan.one ((not o is_meta) andf (not o Symbol.is_blank) andf Symbol.not_eof);

  fun read_int ["0", "0"] = ~1

    | read_int cs = #1 (Library.read_int cs);

  val scan_sym =

    $$ "_" >> K (Argument ("", 0)) ||

    $$ "\\<index>" >> K index ||

    $$ "(" |-- Scan.any Symbol.is_digit >> (Bg o read_int) ||

    $$ ")" >> K En ||

    $$ "/" -- $$ "/" >> K (Brk ~1) ||

    $$ "/" |-- Scan.any Symbol.is_blank >> (Brk o length) ||

    Scan.any1 Symbol.is_blank >> (Space o implode) ||

    Scan.repeat1 scan_delim_char >> (Delim o implode);

  val scan_symb =

    scan_sym >> Some ||

    $$ "'" -- Scan.one Symbol.is_blank >> K None;

  val scan_symbs = Scan.repeat scan_symb --| Scan.ahead (Scan.one (not_equal "'"));

  val read_symbs = mapfilter I o the o Scan.read Symbol.stopper scan_symbs;

  fun unique_index xsymbs =

    if length (filter is_index xsymbs) <= 1 then xsymbs

    else error "Duplicate index arguments (\\<index>)";

in

  val read_mixfix = unique_index o read_symbs o Symbol.explode;

  val mfix_args = length o filter is_argument o read_mixfix;

  val escape_mfix = implode o map (fn s => if is_meta s then "'" ^ s else s) o Symbol.explode;

end;

(* mfix_to_xprod *)

fun mfix_to_xprod convert logtypes (mfix as Mfix (sy, typ, const, pris, pri)) =

  let

    fun check_pri p =

      if p >= 0 andalso p <= max_pri then ()

      else err_in_mfix ("Precedence out of range: " ^ string_of_int p) mfix;

    fun blocks_ok [] 0 = true

      | blocks_ok [] _ = false

      | blocks_ok (Bg _ :: syms) n = blocks_ok syms (n + 1)

      | blocks_ok (En :: _) 0 = false

      | blocks_ok (En :: syms) n = blocks_ok syms (n - 1)

      | blocks_ok (_ :: syms) n = blocks_ok syms n;

    fun check_blocks syms =

      if blocks_ok syms 0 then ()

      else err_in_mfix "Unbalanced block parentheses" mfix;

    val cons_fst = apfst o cons;

    fun add_args [] ty [] = ([], typ_to_nonterm1 ty)

      | add_args [] _ _ = err_in_mfix "Too many precedences" mfix

      | add_args ((arg as Argument ("index", _)) :: syms) ty ps =

          cons_fst arg (add_args syms ty ps)

      | add_args (Argument _ :: syms) (Type ("fun", [ty, tys])) [] =

          cons_fst (Argument (typ_to_nonterm ty, 0)) (add_args syms tys [])

      | add_args (Argument _ :: syms) (Type ("fun", [ty, tys])) (p :: ps) =

          cons_fst (Argument (typ_to_nonterm ty, p)) (add_args syms tys ps)

      | add_args (Argument _ :: _) _ _ =

          err_in_mfix "More arguments than in corresponding type" mfix

      | add_args (sym :: syms) ty ps = cons_fst sym (add_args syms ty ps);

    fun rem_pri (Argument (s, _)) = Argument (s, chain_pri)

      | rem_pri sym = sym;

    fun logify_types copy_prod (a as (Argument (s, p))) =

          if s mem logtypes then Argument (logic, p) else a

      | logify_types _ a = a;

    val raw_symbs = read_mixfix sy handle ERROR => err_in_mfix "" mfix;

    val args = filter (fn Argument _ => true | _ => false) raw_symbs;

    val (const', typ', parse_rules) =

      if not (exists is_index args) then (const, typ, [])

      else

        let

          val indexed_const = if const <> "" then "_indexed_" ^ const

            else err_in_mfix "Missing constant name for indexed syntax" mfix;

          val rangeT = Term.range_type typ handle Match =>

            err_in_mfix "Missing structure argument for indexed syntax" mfix;

          val xs = map Ast.Variable (Term.invent_names [] "xa" (length args - 1));

          val (xs1, xs2) = Library.splitAt (Library.find_index is_index args, xs);

          val i = Ast.Variable "i";

          val lhs = Ast.mk_appl (Ast.Constant indexed_const)

            (xs1 @ [Ast.mk_appl (Ast.Constant "_index") [i]] @ xs2);

          val rhs = Ast.mk_appl (Ast.Constant const) (i :: xs);

        in (indexed_const, rangeT, [(lhs, rhs)]) end;

    val (symbs, lhs) = add_args raw_symbs typ' pris;

    val copy_prod =

      lhs mem ["prop", "logic"]

        andalso const <> ""

        andalso not (null symbs)

        andalso not (exists is_delim symbs);

    val lhs' =

      if convert andalso not copy_prod then

       (if lhs mem logtypes then logic

        else if lhs = "prop" then sprop else lhs)

      else lhs;

    val symbs' = map (logify_types copy_prod) symbs;

    val xprod = XProd (lhs', symbs', const', pri);

    val _ = (seq check_pri pris; check_pri pri; check_blocks symbs');

    val xprod' =

      if Lexicon.is_terminal lhs' then err_in_mfix ("Illegal lhs: " ^ lhs') mfix

      else if const <> "" then xprod

      else if length (filter is_argument symbs') <> 1 then

        err_in_mfix "Copy production must have exactly one argument" mfix

      else if exists is_terminal symbs' then xprod

      else XProd (lhs', map rem_pri symbs', "", chain_pri);

  in (xprod', parse_rules) end;

(** datatype syn_ext **)

datatype syn_ext =

  SynExt of {

    logtypes: string list,

    xprods: xprod list,

    consts: string list,

    prmodes: string list,

    parse_ast_translation: (string * (Ast.ast list -> Ast.ast)) list,

    parse_rules: (Ast.ast * Ast.ast) list,

    parse_translation: (string * (term list -> term)) list,

    print_translation: (string * (bool -> typ -> term list -> term)) list,

    print_rules: (Ast.ast * Ast.ast) list,

    print_ast_translation: (string * (Ast.ast list -> Ast.ast)) list,

    token_translation: (string * string * (string -> string * real)) list}

(* syn_ext *)

fun mk_syn_ext convert logtypes mfixes consts trfuns tokentrfuns (parse_rules, print_rules) =

  let

    val (parse_ast_translation, parse_translation, print_translation,

      print_ast_translation) = trfuns;

    val logtypes' = logtypes \ "prop";

    val (xprods, parse_rules') = map (mfix_to_xprod convert logtypes') mfixes

      |> split_list |> apsnd (rev o flat);

    val mfix_consts = distinct (map (fn Mfix x => #3 x) mfixes @ map (fn XProd x => #3 x) xprods);

  in

    SynExt {

      logtypes = logtypes',

      xprods = xprods,

      consts = consts union_string mfix_consts,

      prmodes = distinct (map (fn (m, _, _) => m) tokentrfuns),

      parse_ast_translation = parse_ast_translation,

      parse_rules = parse_rules' @ parse_rules,

      parse_translation = parse_translation,

      print_translation = print_translation,

      print_rules = map swap parse_rules' @ print_rules,

      print_ast_translation = print_ast_translation,

      token_translation = tokentrfuns}

  end;

val syn_ext = mk_syn_ext true;

fun syn_ext_logtypes logtypes =

  syn_ext logtypes [] [] ([], [], [], []) [] ([], []);

fun syn_ext_const_names logtypes cs =

  syn_ext logtypes [] cs ([], [], [], []) [] ([], []);

fun syn_ext_rules logtypes rules =

  syn_ext logtypes [] [] ([], [], [], []) [] rules;

fun syn_ext_trfuns logtypes trfuns =

  syn_ext logtypes [] [] trfuns [] ([], []);

fun syn_ext_tokentrfuns logtypes tokentrfuns =

  syn_ext logtypes [] [] ([], [], [], []) tokentrfuns ([], []);

(* pure_ext *)

val pure_ext = mk_syn_ext false []

  [Mfix ("_", spropT --> propT, "", [0], 0),

   Mfix ("_", logicT --> anyT, "", [0], 0),

   Mfix ("_", spropT --> anyT, "", [0], 0),

   Mfix ("'(_')", logicT --> logicT, "", [0], max_pri),

   Mfix ("'(_')", spropT --> spropT, "", [0], max_pri),

   Mfix ("_::_",  [logicT, typeT] ---> logicT, "_constrain", [4, 0], 3),

   Mfix ("_::_",  [spropT, typeT] ---> spropT, "_constrain", [4, 0], 3)]

  []

  ([], [], [], [])

  []

  ([], []);

end;