(*  Title:      Pure/Isar/args.ML

     Author:     Markus Wenzel, TU Muenchen

 Parsing with implicit value assignment.  Concrete argument syntax of

 attributes, methods etc.

 *)

 signature ARGS =

 sig

   type src

   val src: (string * Token.T list) * Position.T -> src

   val dest_src: src -> (string * Token.T list) * Position.T

   val pretty_src: Proof.context -> src -> Pretty.T

   val map_name: (string -> string) -> src -> src

   val morph_values: morphism -> src -> src

   val assignable: src -> src

   val closure: src -> src

   val context: Proof.context context_parser

   val theory: theory context_parser

   val $$$ : string -> string parser

   val add: string parser

   val del: string parser

   val colon: string parser

   val query: string parser

   val bang: string parser

   val query_colon: string parser

   val bang_colon: string parser

   val parens: ('a parser) -> 'a parser

   val bracks: ('a parser) -> 'a parser

   val mode: string -> bool context_parser

   val maybe: 'a parser -> 'a option parser

   val name_source: string parser

   val name_source_position: (Symbol_Pos.text * Position.T) parser

   val name: string parser

   val binding: binding parser

   val alt_name: string parser

   val symbol: string parser

   val liberal_name: string parser

   val var: indexname parser

   val internal_text: string parser

   val internal_typ: typ parser

   val internal_term: term parser

   val internal_fact: thm list parser

   val internal_attribute: (morphism -> attribute) parser

   val named_text: (string -> string) -> string parser

   val named_typ: (string -> typ) -> typ parser

   val named_term: (string -> term) -> term parser

   val named_fact: (string -> thm list) -> thm list parser

   val named_attribute: (string -> morphism -> attribute) -> (morphism -> attribute) parser

   val typ_abbrev: typ context_parser

   val typ: typ context_parser

   val term: term context_parser

   val term_abbrev: term context_parser

   val prop: term context_parser

   val type_name: bool -> string context_parser

   val const: bool -> string context_parser

   val const_proper: bool -> string context_parser

   val goal_spec: ((int -> tactic) -> tactic) context_parser

   val parse: Token.T list parser

   val parse1: (string -> bool) -> Token.T list parser

   val attribs: (string -> string) -> src list parser

   val opt_attribs: (string -> string) -> src list parser

   val thm_name: (string -> string) -> string -> (binding * src list) parser

   val opt_thm_name: (string -> string) -> string -> (binding * src list) parser

   val syntax: string -> 'a context_parser -> src -> Context.generic -> 'a * Context.generic

   val context_syntax: string -> 'a context_parser -> src -> Proof.context -> 'a * Proof.context

 end;

 structure Args: ARGS =

 struct

 (** datatype src **)

 datatype src = Src of (string * Token.T list) * Position.T;

 val src = Src;

 fun dest_src (Src src) = src;

 fun pretty_src ctxt src =

   let

     val prt_thm = Pretty.backquote o Display.pretty_thm ctxt;

     fun prt arg =

       (case Token.get_value arg of

         SOME (Token.Text s) => Pretty.str (quote s)

       | SOME (Token.Typ T) => Syntax.pretty_typ ctxt T

       | SOME (Token.Term t) => Syntax.pretty_term ctxt t

       | SOME (Token.Fact ths) => Pretty.enclose "(" ")" (Pretty.breaks (map prt_thm ths))

       | _ => Pretty.str (Token.unparse arg));

     val (s, args) = #1 (dest_src src);

   in Pretty.block (Pretty.breaks (Pretty.str s :: map prt args)) end;

 fun map_name f (Src ((s, args), pos)) = Src ((f s, args), pos);

 fun map_args f (Src ((s, args), pos)) = Src ((s, map f args), pos);

 (* values *)

 fun morph_values phi = map_args (Token.map_value

   (fn Token.Text s => Token.Text s

     | Token.Typ T => Token.Typ (Morphism.typ phi T)

     | Token.Term t => Token.Term (Morphism.term phi t)

     | Token.Fact ths => Token.Fact (Morphism.fact phi ths)

     | Token.Attribute att => Token.Attribute (Morphism.transform phi att)));

 val assignable = map_args Token.assignable;

 val closure = map_args Token.closure;

 (** argument scanners **)

 (* context *)

 fun context x = (Scan.state >> Context.proof_of) x;

 fun theory x = (Scan.state >> Context.theory_of) x;

 (* basic *)

 fun token atom = Scan.ahead Parse.not_eof --| atom;

 val ident = token

   (Parse.short_ident || Parse.long_ident || Parse.sym_ident || Parse.term_var ||

     Parse.type_ident || Parse.type_var || Parse.number);

 val string = token (Parse.string || Parse.verbatim);

 val alt_string = token Parse.alt_string;

 val symbolic = token Parse.keyword_ident_or_symbolic;

 fun $$$ x = (ident >> Token.content_of || Parse.keyword)

   :|-- (fn y => if x = y then Scan.succeed x else Scan.fail);

 val named = ident || string;

 val add = $$$ "add";

 val del = $$$ "del";

 val colon = $$$ ":";

 val query = $$$ "?";

 val bang = $$$ "!";

 val query_colon = $$$ "?" ^^ $$$ ":";

 val bang_colon = $$$ "!" ^^ $$$ ":";

 fun parens scan = $$$ "(" |-- scan --| $$$ ")";

 fun bracks scan = $$$ "[" |-- scan --| $$$ "]";

 fun mode s = Scan.lift (Scan.optional (parens ($$$ s) >> K true) false);

 fun maybe scan = $$$ "_" >> K NONE || scan >> SOME;

 val name_source = named >> Token.source_of;

 val name_source_position = named >> Token.source_position_of;

 val name = named >> Token.content_of;

 val binding = Parse.position name >> Binding.make;

 val alt_name = alt_string >> Token.content_of;

 val symbol = symbolic >> Token.content_of;

 val liberal_name = symbol || name;

 val var = (ident >> Token.content_of) :|-- (fn x =>

   (case Lexicon.read_variable x of SOME v => Scan.succeed v | NONE => Scan.fail));

 (* values *)

 fun value dest = Scan.some (fn arg =>

   (case Token.get_value arg of SOME v => (SOME (dest v) handle Match => NONE) | NONE => NONE));

 fun evaluate mk eval arg =

   let val x = eval arg in (Token.assign (SOME (mk x)) arg; x) end;

 val internal_text = value (fn Token.Text s => s);

 val internal_typ = value (fn Token.Typ T => T);

 val internal_term = value (fn Token.Term t => t);

 val internal_fact = value (fn Token.Fact ths => ths);

 val internal_attribute = value (fn Token.Attribute att => att);

 fun named_text intern = internal_text || named >> evaluate Token.Text (intern o Token.content_of);

 fun named_typ readT = internal_typ || named >> evaluate Token.Typ (readT o Token.source_of);

 fun named_term read = internal_term || named >> evaluate Token.Term (read o Token.source_of);

 fun named_fact get = internal_fact || named >> evaluate Token.Fact (get o Token.content_of) ||

   alt_string >> evaluate Token.Fact (get o Token.source_of);

 fun named_attribute att =

   internal_attribute || named >> evaluate Token.Attribute (att o Token.content_of);

 (* terms and types *)

 val typ_abbrev = Scan.peek (named_typ o ProofContext.read_typ_abbrev o Context.proof_of);

 val typ = Scan.peek (named_typ o Syntax.read_typ o Context.proof_of);

 val term = Scan.peek (named_term o Syntax.read_term o Context.proof_of);

 val term_abbrev = Scan.peek (named_term o ProofContext.read_term_abbrev o Context.proof_of);

 val prop = Scan.peek (named_term o Syntax.read_prop o Context.proof_of);

 (* type and constant names *)

 fun type_name strict =

   Scan.peek (fn ctxt => named_typ (ProofContext.read_type_name (Context.proof_of ctxt) strict))

   >> (fn Type (c, _) => c | TFree (a, _) => a | _ => "");

 fun const strict =

   Scan.peek (fn ctxt => named_term (ProofContext.read_const (Context.proof_of ctxt) strict dummyT))

   >> (fn Const (c, _) => c | Free (x, _) => x | _ => "");

 fun const_proper strict =

   Scan.peek (fn ctxt => named_term (ProofContext.read_const_proper (Context.proof_of ctxt) strict))

   >> (fn Const (c, _) => c | _ => "");

 (* improper method arguments *)

 val from_to =

   Parse.nat -- ($$$ "-" |-- Parse.nat) >> (fn (i, j) => fn tac => Seq.INTERVAL tac i j) ||

   Parse.nat --| $$$ "-" >> (fn i => fn tac => fn st => Seq.INTERVAL tac i (Thm.nprems_of st) st) ||

   Parse.nat >> (fn i => fn tac => tac i) ||

   $$$ "!" >> K ALLGOALS;

 val goal = $$$ "[" |-- Parse.!!! (from_to --| $$$ "]");

 fun goal_spec x = Scan.lift (Scan.optional goal (fn tac => tac 1)) x;

 (* arguments within outer syntax *)

 fun parse_args is_symid =

   let

     val keyword_symid = token (Parse.keyword_with is_symid);

     fun atom blk = Parse.group "argument"

       (ident || keyword_symid || string || alt_string ||

         (if blk then token (Parse.$$$ ",") else Scan.fail));

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

     and args1 blk x =

       ((Scan.repeat1

         (Scan.repeat1 (atom blk) ||

           argsp "(" ")" ||

           argsp "[" "]")) >> flat) x

     and argsp l r x =

       (token (Parse.$$$ l) ::: Parse.!!! (args true @@@ (token (Parse.$$$ r) >> single))) x;

   in (args, args1) end;

 val parse = #1 (parse_args Token.ident_or_symbolic) false;

 fun parse1 is_symid = #2 (parse_args is_symid) false;

 (* attributes *)

 fun attribs intern =

   let

     val attrib_name = internal_text || (symbolic || named)

       >> evaluate Token.Text (intern o Token.content_of);

     val attrib = Parse.position (attrib_name -- Parse.!!! parse) >> src;

   in $$$ "[" |-- Parse.!!! (Parse.list attrib --| $$$ "]") end;

 fun opt_attribs intern = Scan.optional (attribs intern) [];

 (* theorem specifications *)

 fun thm_name intern s = binding -- opt_attribs intern --| $$$ s;

 fun opt_thm_name intern s =

   Scan.optional

     ((binding -- opt_attribs intern || attribs intern >> pair Binding.empty) --| $$$ s)

     (Binding.empty, []);

 (** syntax wrapper **)

 fun syntax kind scan (Src ((s, args), pos)) st =

   (case Scan.error (Scan.finite' Token.stopper (Scan.option scan)) (st, args) of

     (SOME x, (st', [])) => (x, st')

   | (_, (_, args')) =>

       error (kind ^ " " ^ quote s ^ Position.str_of pos ^ ": bad arguments\n  " ^

         space_implode " " (map Token.unparse args')));

 fun context_syntax kind scan src = apsnd Context.the_proof o syntax kind scan src o Context.Proof;

 end;