(*  Title:      Pure/Syntax/syntax.ML

    ID:         $Id$

    Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen

Root of Isabelle's syntax module.

*)

signature SYNTAX =

sig

  include AST0

  include LEXICON0

  include SYN_EXT0

  include TYPE_EXT0

  include SEXTENSION1

  include PRINTER0

  type syntax

  val type_syn: syntax

  val extend: syntax -> (string -> typ) -> string list * string list * sext -> syntax

  val merge: string list -> syntax -> syntax -> syntax

  val print_gram: syntax -> unit

  val print_trans: syntax -> unit

  val print_syntax: syntax -> unit

  val test_read: syntax -> string -> string -> unit

  val read: syntax -> typ -> string -> term

  val read_typ: syntax -> (indexname -> sort) -> string -> typ

  val simple_read_typ: string -> typ

  val pretty_term: syntax -> term -> Pretty.T

  val pretty_typ: syntax -> typ -> Pretty.T

  val string_of_term: syntax -> term -> string

  val string_of_typ: syntax -> typ -> string

end;

functor SyntaxFun(structure Symtab: SYMTAB and TypeExt: TYPE_EXT

  and SExtension: SEXTENSION and Printer: PRINTER

  sharing SExtension.Parser.SynExt = TypeExt.SynExt = Printer.SynExt)(*: SYNTAX *) = (* FIXME *)

struct

structure SynExt = TypeExt.SynExt;

structure Parser = SExtension.Parser;

structure Lexicon = Parser.Lexicon;

open Lexicon SynExt SynExt.Ast Parser TypeExt SExtension Printer;

(** tables of translation functions **)

(*the ref serves as unique id*)

type 'a trtab = (('a list -> 'a) * unit ref) Symtab.table;

val dest_trtab = Symtab.alist_of;

fun lookup_trtab tab c =

  apsome fst (Symtab.lookup (tab, c));

(* empty, extend, merge trtabs *)

fun err_dup_trfun name c =

  error ("More than one " ^ name ^ " for " ^ quote c);

val empty_trtab = Symtab.null;

fun extend_trtab tab trfuns name =

  Symtab.extend eq_snd (tab, map (fn (c, f) => (c, (f, ref ()))) trfuns)

    handle Symtab.DUPLICATE c => err_dup_trfun name c;

fun merge_trtabs tab1 tab2 name =

  Symtab.merge eq_snd (tab1, tab2)

    handle Symtab.DUPLICATE c => err_dup_trfun name c;

(** tables of translation rules **)

type ruletab = (ast * ast) list Symtab.table;

fun dest_ruletab tab = flat (map snd (Symtab.alist_of tab));

(* lookup_ruletab *)

fun lookup_ruletab tab =

  if Symtab.is_null tab then None

  else Some (fn a => Symtab.lookup_multi (tab, a));

(* empty, extend, merge ruletabs *)

val empty_ruletab = Symtab.null;

fun extend_ruletab tab rules =

  generic_extend (op =) Symtab.dest_multi Symtab.make_multi tab

    (map (fn r => (head_of_rule r, r)) (distinct rules));

fun merge_ruletabs tab1 tab2 =

  generic_merge (op =) Symtab.dest_multi Symtab.make_multi tab1 tab2;

(** datatype syntax **)

datatype syntax =

  Syntax of {

    lexicon: lexicon,

    roots: string list,

    gram: gram,

    consts: string list,

    parse_ast_trtab: ast trtab,

    parse_ruletab: ruletab,

    parse_trtab: term trtab,

    print_trtab: term trtab,

    print_ruletab: ruletab,

    print_ast_trtab: ast trtab,

    prtab: prtab};

(* empty_syntax *)

val empty_syntax =

  Syntax {

    lexicon = empty_lexicon,

    roots = [],

    gram = empty_gram,

    consts = [],

    parse_ast_trtab = empty_trtab,

    parse_ruletab = empty_ruletab,

    parse_trtab = empty_trtab,

    print_trtab = empty_trtab,

    print_ruletab = empty_ruletab,

    print_ast_trtab = empty_trtab,

    prtab = empty_prtab};

(* extend_syntax *)

fun extend_syntax (Syntax tabs) syn_ext =

  let

    val {lexicon, roots = roots1, gram, consts = consts1, parse_ast_trtab,

      parse_ruletab, parse_trtab, print_trtab, print_ruletab, print_ast_trtab,

      prtab} = tabs;

    val SynExt {roots = roots2, xprods, consts = consts2, parse_ast_translation,

      parse_rules, parse_translation, print_translation, print_rules,

      print_ast_translation} = syn_ext;

  in

    Syntax {

      lexicon = extend_lexicon lexicon (delims_of xprods),

      roots = extend_list roots1 roots2,

      gram = extend_gram gram roots2 xprods,

      consts = consts2 union consts1,

      parse_ast_trtab =

        extend_trtab parse_ast_trtab parse_ast_translation "parse ast translation",

      parse_ruletab = extend_ruletab parse_ruletab parse_rules,

      parse_trtab = extend_trtab parse_trtab parse_translation "parse translation",

      print_trtab = extend_trtab print_trtab print_translation "print translation",

      print_ruletab = extend_ruletab print_ruletab print_rules,

      print_ast_trtab =

        extend_trtab print_ast_trtab print_ast_translation "print ast translation",

      prtab = extend_prtab prtab xprods}

  end;

(* merge_syntaxes *)

fun merge_syntaxes (Syntax tabs1) (Syntax tabs2) =

  let

    val {lexicon = lexicon1, roots = roots1, gram = gram1, consts = consts1,

      parse_ast_trtab = parse_ast_trtab1, parse_ruletab = parse_ruletab1,

      parse_trtab = parse_trtab1, print_trtab = print_trtab1,

      print_ruletab = print_ruletab1, print_ast_trtab = print_ast_trtab1,

      prtab = prtab1} = tabs1;

    val {lexicon = lexicon2, roots = roots2, gram = gram2, consts = consts2,

      parse_ast_trtab = parse_ast_trtab2, parse_ruletab = parse_ruletab2,

      parse_trtab = parse_trtab2, print_trtab = print_trtab2,

      print_ruletab = print_ruletab2, print_ast_trtab = print_ast_trtab2,

      prtab = prtab2} = tabs2;

  in

    Syntax {

      lexicon = merge_lexicons lexicon1 lexicon2,

      roots = merge_lists roots1 roots2,

      gram = merge_grams gram1 gram2,

      consts = merge_lists consts1 consts2,

      parse_ast_trtab =

        merge_trtabs parse_ast_trtab1 parse_ast_trtab2 "parse ast translation",

      parse_ruletab = merge_ruletabs parse_ruletab1 parse_ruletab2,

      parse_trtab = merge_trtabs parse_trtab1 parse_trtab2 "parse translation",

      print_trtab = merge_trtabs print_trtab1 print_trtab2 "print translation",

      print_ruletab = merge_ruletabs print_ruletab1 print_ruletab2,

      print_ast_trtab =

        merge_trtabs print_ast_trtab1 print_ast_trtab2 "print ast translation",

      prtab = merge_prtabs prtab1 prtab2}

  end;

(** inspect syntax **)

fun string_of_big_list name prts =

  Pretty.string_of (Pretty.block (Pretty.fbreaks (Pretty.str name :: prts)));

fun string_of_strings name strs =

  Pretty.string_of (Pretty.block (Pretty.breaks

    (map Pretty.str (name :: map quote (sort_strings strs)))));

(* print_gram *)

fun print_gram (Syntax tabs) =

  let

    val {lexicon, roots, gram, ...} = tabs;

  in

    writeln (string_of_strings "lexicon:" (dest_lexicon lexicon));

    writeln (Pretty.string_of (Pretty.block (Pretty.breaks

      (map Pretty.str ("roots:" :: roots)))));

    writeln (string_of_big_list "prods:" (pretty_gram gram))

  end;

(* print_trans *)

fun print_trans (Syntax tabs) =

  let

    fun string_of_trtab name tab =

      string_of_strings name (map fst (dest_trtab tab));

    fun string_of_ruletab name tab =

      string_of_big_list name (map pretty_rule (dest_ruletab tab));

    val {consts, parse_ast_trtab, parse_ruletab, parse_trtab, print_trtab,

      print_ruletab, print_ast_trtab, ...} = tabs;

  in

    writeln (string_of_strings "consts:" consts);

    writeln (string_of_trtab "parse_ast_translation:" parse_ast_trtab);

    writeln (string_of_ruletab "parse_rules:" parse_ruletab);

    writeln (string_of_trtab "parse_translation:" parse_trtab);

    writeln (string_of_trtab "print_translation:" print_trtab);

    writeln (string_of_ruletab "print_rules:" print_ruletab);

    writeln (string_of_trtab "print_ast_translation:" print_ast_trtab)

  end;

(* print_syntax *)

fun print_syntax syn = (print_gram syn; print_trans syn);

(** read **)

(* read_ast *)

fun read_ast (Syntax tabs) xids root str =

  let

    val {lexicon, gram, parse_ast_trtab, ...} = tabs;

  in

    pt_to_ast (lookup_trtab parse_ast_trtab)

      (parse gram root (tokenize lexicon xids str))

  end;

(* test_read *)

fun test_read (Syntax tabs) root str =

  let

    val {lexicon, gram, parse_ast_trtab, parse_ruletab, ...} = tabs;

    val toks = tokenize lexicon false str;

    val _ = writeln ("tokens: " ^ space_implode " " (map display_token toks));

    val pt = parse gram root toks;

    val raw_ast = pt_to_ast (K None) pt;

    val _ = writeln ("raw: " ^ str_of_ast raw_ast);

    val pre_ast = pt_to_ast (lookup_trtab parse_ast_trtab) pt;

    val _ = normalize true true (lookup_ruletab parse_ruletab) pre_ast;

  in () end;

(* read *)

fun read (syn as Syntax tabs) ty str =

  let

    val {parse_ruletab, parse_trtab, ...} = tabs;

    val ast = read_ast syn false (typ_to_nonterm ty) str;

  in

    ast_to_term (lookup_trtab parse_trtab)

      (normalize_ast (lookup_ruletab parse_ruletab) ast)

  end;

(* read types *)

fun read_typ syn def_sort str =

  typ_of_term def_sort (read syn typeT str);

val type_syn = extend_syntax empty_syntax type_ext;

fun simple_read_typ str = read_typ type_syn (K []) str;

(* read rules *)

fun read_rule syn (xrule as ((_, lhs_src), (_, rhs_src))) =

  let

    val Syntax {consts, ...} = syn;

    fun constantify (ast as Constant _) = ast

      | constantify (ast as Variable x) =

          if x mem consts then Constant x else ast

      | constantify (Appl asts) = Appl (map constantify asts);

    fun read_pat (root, str) =

      constantify (read_ast syn true root str)

        handle ERROR => error ("The error above occurred in " ^ quote str);

    val rule as (lhs, rhs) = (pairself read_pat) xrule;

  in

    (case rule_error rule of

      Some msg =>

        error ("Error in syntax translation rule: " ^ msg ^

          "\nexternal: " ^ quote lhs_src ^ "  ->  " ^ quote rhs_src ^

          "\ninternal: " ^ str_of_ast lhs ^ "  ->  " ^ str_of_ast rhs)

    | None => rule)

  end;

fun read_xrules syn xrules =

  let

    fun right_rule (xpat1 |-> xpat2) = Some (xpat1, xpat2)

      | right_rule (xpat1 <-| xpat2) = None

      | right_rule (xpat1 <-> xpat2) = Some (xpat1, xpat2);

    fun left_rule (xpat1 |-> xpat2) = None

      | left_rule (xpat1 <-| xpat2) = Some (xpat2, xpat1)

      | left_rule (xpat1 <-> xpat2) = Some (xpat2, xpat1);

  in

    (map (read_rule syn) (mapfilter right_rule xrules),

     map (read_rule syn) (mapfilter left_rule xrules))

  end;

(** pretty terms or typs **)

fun pretty_t t_to_ast pretty_t (syn as Syntax tabs) t =

  let

    val {print_trtab, print_ruletab, print_ast_trtab, prtab, ...} = tabs;

    val ast = t_to_ast (lookup_trtab print_trtab) t;

  in

    pretty_t prtab (lookup_trtab print_ast_trtab)

      (normalize_ast (lookup_ruletab print_ruletab) ast)

  end;

val pretty_term = pretty_t term_to_ast pretty_term_ast;

val pretty_typ = pretty_t typ_to_ast pretty_typ_ast;

fun string_of_term syn t = Pretty.string_of (pretty_term syn t);

fun string_of_typ syn ty = Pretty.string_of (pretty_typ syn ty);

(** build syntax **)

(* extend *)

fun extend syn0 read_ty (all_roots, xconsts, sext) =

  let

    val Syntax {roots, ...} = syn0;

    val syn1 = extend_syntax syn0

      (syn_ext_of_sext (all_roots \\ roots) xconsts read_ty sext);

    val syn2 = extend_syntax syn1

      (syn_ext_rules (read_xrules syn1 (xrules_of sext)));

  in syn2 end;

(* merge *)

fun merge all_roots syn1 syn2 =

  let

    val syn as (Syntax {roots, ...}) = merge_syntaxes syn1 syn2;

  in

    (case all_roots \\ roots of

      [] => syn

    | new_roots => (writeln (string_of_strings "DEBUG new roots:" new_roots); (* FIXME debug *)

        extend_syntax syn (syn_ext_roots new_roots)))

  end;

end;