(*  Title:      Pure/Isar/outer_parse.ML

     ID:         $Id$

     Author:     Markus Wenzel, TU Muenchen

 Generic parsers for Isabelle/Isar outer syntax.

 *)

 signature OUTER_PARSE =

 sig

   type token

   val group: string -> (token list -> 'a) -> token list -> 'a

   val !!! : (token list -> 'a) -> token list -> 'a

   val $$$ : string -> token list -> string * token list

   val position: (token list -> 'a * 'b) -> token list -> ('a * Position.T) * 'b

   val command: token list -> string * token list

   val keyword: token list -> string * token list

   val short_ident: token list -> string * token list

   val long_ident: token list -> string * token list

   val sym_ident: token list -> string * token list

   val term_var: token list -> string * token list

   val text_var: token list -> string * token list

   val type_ident: token list -> string * token list

   val type_var: token list -> string * token list

   val number: token list -> string * token list

   val string: token list -> string * token list

   val verbatim: token list -> string * token list

   val sync: token list -> string * token list

   val eof: token list -> string * token list

   val not_eof: token list -> token * token list

   val nat: token list -> int * token list

   val enum: string -> (token list -> 'a * token list) -> token list -> 'a list * token list

   val enum1: string -> (token list -> 'a * token list) -> token list -> 'a list * token list

   val list: (token list -> 'a * token list) -> token list -> 'a list * token list

   val list1: (token list -> 'a * token list) -> token list -> 'a list * token list

   val and_list: (token list -> 'a * token list) -> token list -> 'a list * token list

   val and_list1: (token list -> 'a * token list) -> token list -> 'a list * token list

   val name: token list -> bstring * token list

   val xname: token list -> xstring * token list

   val text: token list -> string * token list

   val comment: token list -> Comment.text * token list

   val marg_comment: token list -> Comment.text * token list

   val interest: token list -> Comment.interest * token list

   val sort: token list -> xsort * token list

   val arity: token list -> (xsort list * xsort) * token list

   val simple_arity: token list -> (xsort list * xclass) * token list

   val type_args: token list -> string list * token list

   val typ: token list -> string * token list

   val opt_infix: token list -> Syntax.mixfix * token list

   val opt_mixfix: token list -> Syntax.mixfix * token list

   val const: token list -> (bstring * string * Syntax.mixfix) * token list

   val term: token list -> string * token list

   val prop: token list -> string * token list

   val propp: token list -> (string * (string list * string list)) * token list

   val termp: token list -> (string * string list) * token list

   val attribs: token list -> Args.src list * token list

   val opt_attribs: token list -> Args.src list * token list

   val thm_name: string -> token list -> (bstring * Args.src list) * token list

   val opt_thm_name: string -> token list -> (bstring * Args.src list) * token list

   val spec_name: token list -> ((bstring * string) * Args.src list) * token list

   val spec_opt_name: token list -> ((bstring * string) * Args.src list) * token list

   val xthm: token list -> (xstring * Args.src list) * token list

   val xthms1: token list -> (xstring * Args.src list) list * token list

   val method: token list -> Method.text * token list

   val triple1: ('a * 'b) * 'c -> 'a * 'b * 'c

   val triple2: 'a * ('b * 'c) -> 'a * 'b * 'c

   val triple_swap: ('a * 'b) * 'c -> ('a * 'c) * 'b

 end;

 structure OuterParse: OUTER_PARSE =

 struct

 type token = OuterLex.token;

 (** error handling **)

 (* group atomic parsers (no cuts!) *)

 fun fail_with s = Scan.fail_with

   (fn [] => s ^ " expected (past end-of-file!)"

     | (tok :: _) => s ^ " expected,\nbut " ^ OuterLex.name_of tok ^ " " ^

       quote (OuterLex.val_of tok) ^ OuterLex.pos_of tok ^ " was found");

 fun group s scan = scan || fail_with s;

 (* cut *)

 fun !!! scan =

   let

     fun get_pos [] = " (past end-of-file!)"

       | get_pos (tok :: _) = OuterLex.pos_of tok;

     fun err (toks, None) = "Outer syntax error" ^ get_pos toks

       | err (toks, Some msg) = "Outer syntax error" ^ get_pos toks ^ ": " ^ msg;

   in Scan.!! err scan end;

 (** basic parsers **)

 (* utils *)

 fun triple1 ((x, y), z) = (x, y, z);

 fun triple2 (x, (y, z)) = (x, y, z);

 fun triple_swap ((x, y), z) = ((x, z), y);

 (* tokens *)

 fun position scan =

   (Scan.ahead (Scan.one OuterLex.not_eof) >> OuterLex.position_of) -- scan >> Library.swap;

 fun kind k =

   group (OuterLex.str_of_kind k)

     (Scan.one (OuterLex.is_kind k) >> OuterLex.val_of);

 val command = kind OuterLex.Command;

 val keyword = kind OuterLex.Keyword;

 val short_ident = kind OuterLex.Ident;

 val long_ident = kind OuterLex.LongIdent;

 val sym_ident = kind OuterLex.SymIdent;

 val term_var = kind OuterLex.Var;

 val text_var = kind OuterLex.TextVar;

 val type_ident = kind OuterLex.TypeIdent;

 val type_var = kind OuterLex.TypeVar;

 val number = kind OuterLex.Nat;

 val string = kind OuterLex.String;

 val verbatim = kind OuterLex.Verbatim;

 val sync = kind OuterLex.Sync;

 val eof = kind OuterLex.EOF;

 fun $$$ x =

   group (OuterLex.str_of_kind OuterLex.Keyword ^ " " ^ quote x)

     (Scan.one (OuterLex.keyword_with (equal x)) >> OuterLex.val_of);

 val nat = number >> (fst o Term.read_int o Symbol.explode);

 val not_eof = Scan.one OuterLex.not_eof;

 (* enumerations *)

 fun enum1 sep scan = scan -- Scan.repeat ($$$ sep |-- !!! scan) >> op ::;

 fun enum sep scan = enum1 sep scan || Scan.succeed [];

 fun list1 scan = enum1 "," scan;

 fun list scan = enum "," scan;

 fun and_list1 scan = enum1 "and" scan;

 fun and_list scan = enum "and" scan;

 (* names and text *)

 val name = group "name declaration" (short_ident || sym_ident || string);

 val xname = group "name reference" (short_ident || long_ident || sym_ident || string);

 val text = group "text" (short_ident || long_ident || sym_ident || string || verbatim);

 (* formal comments *)

 val comment = text >> Comment.plain;

 val marg_comment = Scan.optional ($$$ "--" |-- comment) Comment.none;

 val interest = Scan.optional ($$$ "%%" >> K Comment.no_interest ||

   $$$ "%" |-- Scan.optional nat 1 >> Comment.interest) Comment.default_interest;

 (* sorts and arities *)

 val sort =

   xname >> single || $$$ "{" |-- !!! (list xname --| $$$ "}");

 fun gen_arity cod =

   Scan.optional ($$$ "(" |-- !!! (Scan.repeat1 sort --| $$$ ")")) [] -- cod;

 val arity = gen_arity sort;

 val simple_arity = gen_arity name;

 (* types *)

 val typ =

   group "type" (short_ident || long_ident || sym_ident || type_ident || type_var || string);

 val type_args =

   type_ident >> single ||

   $$$ "(" |-- !!! (list1 type_ident --| $$$ ")") ||

   Scan.succeed [];

 (* mixfix annotations *)

 val infxl = $$$ "infixl" |-- !!! (nat >> Syntax.Infixl || string -- nat >> Syntax.InfixlName);

 val infxr = $$$ "infixr" |-- !!! (nat >> Syntax.Infixr || string -- nat >> Syntax.InfixrName);

 val binder =

   $$$ "binder" |--

     !!! (string -- ($$$ "[" |-- nat --| $$$ "]" -- nat || nat >> (fn n => (n, n))))

   >> (Syntax.Binder o triple2);

 val opt_pris = Scan.optional ($$$ "[" |-- !!! (list nat --| $$$ "]")) [];

 val mixfix =

   string -- opt_pris -- Scan.optional nat Syntax.max_pri

   >> (Syntax.Mixfix o triple1);

 fun opt_fix fix =

   Scan.optional ($$$ "(" |-- !!! (fix --| $$$ ")")) Syntax.NoSyn;

 val opt_infix = opt_fix (infxl || infxr);

 val opt_mixfix = opt_fix (mixfix || binder || infxl || infxr);

 (* consts *)

 val const =

   name -- ($$$ "::" |-- !!! (typ -- opt_mixfix)) >> triple2;

 (* terms *)

 val trm = short_ident || long_ident || sym_ident || term_var || text_var || number || string;

 val term = group "term" trm;

 val prop = group "proposition" trm;

 (* patterns *)

 val is_terms = Scan.repeat1 ($$$ "is" |-- term);

 val is_props = Scan.repeat1 ($$$ "is" |-- prop);

 val concl_props = $$$ "concl" |-- !!! is_props;

 val any_props = is_props -- Scan.optional concl_props [] || concl_props >> pair [];

 val propp = prop -- Scan.optional ($$$ "(" |-- !!! (any_props --| $$$ ")")) ([], []);

 val termp = term -- Scan.optional ($$$ "(" |-- !!! (is_terms --| $$$ ")")) [];

 (* arguments *)

 fun keyword_symid is_symid = Scan.one (OuterLex.keyword_with is_symid) >> OuterLex.val_of;

 fun atom_arg is_symid blk =

   group "argument"

     (position (short_ident || long_ident || sym_ident || term_var || text_var ||

         type_ident || type_var || number) >> Args.ident ||

       position (keyword_symid is_symid) >> Args.keyword ||

       position string >> Args.string ||

       position (if blk then $$$ "," else Scan.fail) >> Args.keyword);

 fun paren_args l r scan = position ($$$ l) -- !!! (scan true -- position ($$$ r))

   >> (fn (x, (ys, z)) => Args.keyword x :: ys @ [Args.keyword z]);

 fun args is_symid blk x = Scan.optional (args1 is_symid blk) [] x

 and args1 is_symid blk x =

   ((Scan.repeat1

     (Scan.repeat1 (atom_arg is_symid blk) ||

       paren_args "(" ")" (args is_symid) ||

       paren_args "{" "}" (args is_symid) ||

       paren_args "[" "]" (args is_symid))) >> flat) x;

 (* theorem specifications *)

 val attrib = position (xname -- !!! (args OuterLex.is_sid false)) >> Args.src;

 val attribs = $$$ "[" |-- !!! (list attrib --| $$$ "]");

 val opt_attribs = Scan.optional attribs [];

 fun thm_name s = name -- opt_attribs --| $$$ s;

 fun opt_thm_name s =

   Scan.optional ((name -- opt_attribs || (attribs >> pair "")) --| $$$ s) ("", []);;

 val spec_name = thm_name ":" -- prop >> (fn ((x, y), z) => ((x, z), y));

 val spec_opt_name = opt_thm_name ":" -- prop >> (fn ((x, y), z) => ((x, z), y));

 val xthm = xname -- opt_attribs;

 val xthms1 = Scan.repeat1 xthm;

 (* proof methods *)

 fun is_symid_meth s =

   s <> "|" andalso s <> "?" andalso s <> "*" andalso s <> "+" andalso OuterLex.is_sid s;

 fun meth4 x =

  (position (xname >> rpair []) >> (Method.Source o Args.src) ||

   $$$ "(" |-- !!! (meth0 --| $$$ ")")) x

 and meth3 x =

  (meth4 --| $$$ "?" >> Method.Try ||

   meth4 --| $$$ "*" >> Method.Repeat ||

   meth4 --| $$$ "+" >> Method.Repeat1 ||

   meth4) x

 and meth2 x =

  (position (xname -- args1 is_symid_meth false) >> (Method.Source o Args.src) ||

   meth3) x

 and meth1 x = (enum1 "," meth2 >> (fn [m] => m | ms => Method.Then ms)) x

 and meth0 x = (enum1 "|" meth1 >> (fn [m] => m | ms => Method.Orelse ms)) x;

 val method = meth3;

 end;