(*  Title:      Pure/Syntax/syntax.ML

    ID:         $Id$

    Author:     Tobias Nipkow and Markus Wenzel, TU Muenchen

Root of Isabelle's syntax module.

*)

infix |-> <-| <->;

signature BASIC_SYNTAX =

sig

  include AST0

  include SYN_TRANS0

  include MIXFIX0

  include PRINTER0

end;

signature SYNTAX =

sig

  include AST1

  include LEXICON0

  include SYN_EXT0

  include TYPE_EXT0

  include SYN_TRANS1

  include MIXFIX1

  include PRINTER0

  datatype 'a trrule =

    |-> of 'a * 'a |

    <-| of 'a * 'a |

    <-> of 'a * 'a

  type syntax

  val extend_log_types: syntax -> string list -> syntax

  val extend_type_gram: syntax -> (string * int * mixfix) list -> syntax

  val extend_const_gram: syntax -> string * bool -> (string * typ * mixfix) list -> syntax

  val extend_consts: syntax -> string list -> syntax

  val extend_trfuns: syntax ->

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

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

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

    (string * (ast list -> ast)) list -> syntax

  val extend_trfunsT: syntax -> (string * (typ -> term list -> term)) list -> syntax

  val extend_trrules: syntax -> (string * string) trrule list -> syntax

  val extend_trrules_i: syntax -> ast trrule list -> syntax

  val merge_syntaxes: syntax -> syntax -> syntax

  val type_syn: syntax

  val pure_syn: 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 list

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

  val simple_read_typ: string -> typ

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

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

  val string_of_term: bool -> syntax -> term -> string

  val string_of_typ: syntax -> typ -> string

  val simple_string_of_typ: typ -> string

  val simple_pprint_typ: typ -> pprint_args -> unit

  val ambiguity_level: int ref

end;

structure Syntax : SYNTAX =

struct

open Lexicon SynExt Ast Parser TypeExt SynTrans Mixfix Printer;

(** tables of translation functions **)

(*the ref serves as unique id*)

(*does not subsume typed print translations*)

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

val dest_trtab = Symtab.dest;

fun lookup_trtab tab c =

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

(* empty, extend, merge trtabs *)

fun err_dup_trfuns name cs =

  error ("More than one " ^ name ^ " for " ^ commas_quote cs);

val empty_trtab = Symtab.null;

fun extend_trtab tab trfuns name =

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

    handle Symtab.DUPS cs => err_dup_trfuns name cs;

fun merge_trtabs tab1 tab2 name =

  Symtab.merge eq_snd (tab1, tab2)

    handle Symtab.DUPS cs => err_dup_trfuns name cs;

(** tables of translation rules **)

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

fun dest_ruletab tab = flat (map snd (Symtab.dest 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,

    logtypes: string list,

    gram: gram,

    consts: string list,

    parse_ast_trtab: ast trtab,

    parse_ruletab: ruletab,

    parse_trtab: term trtab,

    print_trtab: ((typ -> term list -> term) * unit ref) Symtab.table,

    print_ruletab: ruletab,

    print_ast_trtab: ast trtab,

    prtabs: prtabs};

(* empty_syntax *)

val empty_syntax =

  Syntax {

    lexicon = empty_lexicon,

    logtypes = [],

    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,

    prtabs = empty_prtabs};

(* extend_syntax *)

fun extend_syntax (mode, inout) (Syntax tabs) syn_ext =

  let

    val {lexicon, logtypes = logtypes1, gram, consts = consts1,

      parse_ast_trtab, parse_ruletab, parse_trtab, print_trtab, print_ruletab,

      print_ast_trtab, prtabs} = tabs;

    val SynExt {logtypes = logtypes2, xprods, consts = consts2, parse_ast_translation,

      parse_rules, parse_translation, print_translation, print_rules,

      print_ast_translation} = syn_ext;

  in

    Syntax {

      lexicon = if inout then extend_lexicon lexicon (delims_of xprods) else lexicon,

      logtypes = extend_list logtypes1 logtypes2,

      gram = if inout then extend_gram gram xprods else gram,

      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",

      prtabs = extend_prtabs prtabs mode xprods}

  end;

(* merge_syntaxes *)

fun merge_syntaxes (Syntax tabs1) (Syntax tabs2) =

  let

    val {lexicon = lexicon1, logtypes = logtypes1, 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,

      prtabs = prtabs1} = tabs1;

    val {lexicon = lexicon2, logtypes = logtypes2, 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,

      prtabs = prtabs2} = tabs2;

  in

    Syntax {

      lexicon = merge_lexicons lexicon1 lexicon2,

      logtypes = merge_lists logtypes1 logtypes2,

      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",

      prtabs = merge_prtabs prtabs1 prtabs2}

  end;

(* type_syn *)

val type_syn = extend_syntax ("", true) empty_syntax type_ext;

val pure_syn = extend_syntax ("", true) type_syn pure_ext;

(** inspect syntax **)

fun pretty_strs_qs name strs =

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

(* print_gram *)

fun print_gram (Syntax tabs) =

  let

    val {lexicon, logtypes, gram, prtabs, ...} = tabs;

  in

    Pretty.writeln (pretty_strs_qs "lexicon:" (dest_lexicon lexicon));

    Pretty.writeln (Pretty.strs ("logtypes:" :: logtypes));

    Pretty.writeln (Pretty.big_list "prods:" (pretty_gram gram));

    Pretty.writeln (pretty_strs_qs "print modes:" (prmodes_of prtabs))

  end;

(* print_trans *)

fun print_trans (Syntax tabs) =

  let

    fun pretty_trtab name tab =

      pretty_strs_qs name (map fst (dest_trtab tab));

    fun pretty_ruletab name tab =

      Pretty.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

    Pretty.writeln (pretty_strs_qs "consts:" consts);

    Pretty.writeln (pretty_trtab "parse_ast_translation:" parse_ast_trtab);

    Pretty.writeln (pretty_ruletab "parse_rules:" parse_ruletab);

    Pretty.writeln (pretty_trtab "parse_translation:" parse_trtab);

    Pretty.writeln (pretty_trtab "print_translation:" print_trtab);

    Pretty.writeln (pretty_ruletab "print_rules:" print_ruletab);

    Pretty.writeln (pretty_trtab "print_ast_translation:" print_ast_trtab)

  end;

(* print_syntax *)

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

(** read **)

(* test_read *)

fun test_read (Syntax tabs) root str =

  let

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

    val chars = SymbolFont.read_charnames (explode str);

    val toks = tokenize lexicon false chars;

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

    fun show_pt pt =

      let

        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;

  in

    seq show_pt (parse gram root toks)

  end;

(* read_ast *)

val ambiguity_level = ref 1;

fun read_asts (Syntax tabs) xids root str =

  let

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

    val root' = if root mem logtypes then logic else root;

    val chars = SymbolFont.read_charnames (explode str);

    val pts = parse gram root' (tokenize lexicon xids chars);

    fun show_pt pt = writeln (str_of_ast (pt_to_ast (K None) pt));

  in

    if length pts > ! ambiguity_level then

      (warning ("Ambiguous input " ^ quote str);

       writeln "produces the following parse trees:";

       seq show_pt pts)

    else ();

    map (pt_to_ast (lookup_trtab parse_ast_trtab)) pts

  end;

(* read *)

fun read (syn as Syntax tabs) ty str =

  let

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

    val asts = read_asts syn false (typ_to_nonterm ty) str;

  in

    map (ast_to_term (lookup_trtab parse_trtab))

      (map (normalize_ast (lookup_ruletab parse_ruletab)) asts)

  end;

(* read types *)

fun read_typ syn def_sort str =

  (case read syn typeT str of

    [t] => typ_of_term (raw_term_sorts t) def_sort t

  | _ => sys_error "read_typ: ambiguous type syntax");

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

(** prepare translation rules **)

datatype 'a trrule =

  op |-> of 'a * 'a |

  op <-| of 'a * 'a |

  op <-> of 'a * 'a;

fun map_rule f (x |-> y) = (f x |-> f y)

  | map_rule f (x <-| y) = (f x <-| f y)

  | map_rule f (x <-> y) = (f x <-> f y);

fun right_rule (pat1 |-> pat2) = Some (pat1, pat2)

  | right_rule (pat1 <-| pat2) = None

  | right_rule (pat1 <-> pat2) = Some (pat1, pat2);

fun left_rule (pat1 |-> pat2) = None

  | left_rule (pat1 <-| pat2) = Some (pat2, pat1)

  | left_rule (pat1 <-> pat2) = Some (pat2, pat1);

fun check_rule (rule as (lhs, rhs)) =

  (case rule_error rule of

    Some msg =>

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

        str_of_ast lhs ^ "  ->  " ^ str_of_ast rhs)

  | None => rule);

fun read_pattern syn (root, str) =

  let

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

    fun constify (ast as Constant _) = ast

      | constify (ast as Variable x) =

          if x mem consts then Constant x else ast

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

  in

    (case read_asts syn true root str of

      [ast] => constify ast

    | _ => error ("Syntactically ambiguous input: " ^ quote str))

  end handle ERROR =>

    error ("The error(s) above occurred in translation pattern " ^

      quote str);

fun prep_rules rd_pat raw_rules =

  let val rules = map (map_rule rd_pat) raw_rules in

    (map check_rule (mapfilter right_rule rules),

      map check_rule (mapfilter left_rule rules))

  end

(** pretty terms or typs **)

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

  let

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

    val ast = t_to_ast (lookup_trtab print_trtab) t;

  in

    prt_t curried prtabs (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 false;

fun string_of_term curried syn t =

  Pretty.string_of (pretty_term curried syn t);

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

val simple_string_of_typ = string_of_typ type_syn;

val simple_pprint_typ = Pretty.pprint o Pretty.quote o (pretty_typ type_syn);

(** extend syntax (external interfaces) **)

fun ext_syntax mk_syn_ext prmode (syn as Syntax {logtypes, ...}) decls =

  extend_syntax prmode syn (mk_syn_ext logtypes decls);

fun extend_log_types syn logtypes =

  extend_syntax ("", true) syn (syn_ext_logtypes logtypes);

val extend_type_gram = ext_syntax syn_ext_types ("", true);

fun extend_const_gram syn prmode = ext_syntax syn_ext_consts prmode syn;

val extend_consts = ext_syntax syn_ext_const_names ("", true);

val extend_trfuns = ext_syntax syn_ext_trfuns ("", true);

val extend_trfunsT = ext_syntax syn_ext_trfunsT ("", true);

fun extend_trrules syn rules =

  ext_syntax syn_ext_rules ("", true) syn (prep_rules (read_pattern syn) rules);

fun extend_trrules_i syn rules =

  ext_syntax syn_ext_rules ("", true) syn (prep_rules I rules);

end;