(*  Title:      Pure/Isar/args.ML

     ID:         $Id$

     Author:     Markus Wenzel, TU Muenchen

 Parsing with implicit value assigment.  Concrete argument syntax of

 attributes, methods etc.

 *)

 signature ARGS =

 sig

   type T = OuterLex.token

   type src

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

   val dest_src: src -> (string * 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 maxidx_values: src -> int -> int

   val assignable: src -> src

   val closure: src -> src

   val context: Context.generic * T list -> Context.proof * (Context.generic * T list)

   val theory: Context.generic * T list -> Context.theory * (Context.generic * T list)

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

   val add: T list -> string * T list

   val del: T list -> string * T list

   val colon: T list -> string * T list

   val query: T list -> string * T list

   val bang: T list -> string * T list

   val query_colon: T list -> string * T list

   val bang_colon: T list -> string * T list

   val parens: (T list -> 'a * T list) -> T list -> 'a * T list

   val bracks: (T list -> 'a * T list) -> T list -> 'a * T list

   val mode: string -> 'a * T list -> bool * ('a * T list)

   val maybe: (T list -> 'a * T list) -> T list -> 'a option * T list

   val name: T list -> string * T list

   val alt_name: T list -> string * T list

   val symbol: T list -> string * T list

   val liberal_name: T list -> string * T list

   val var: T list -> indexname * T list

   val internal_text: T list -> string * T list

   val internal_typ: T list -> typ * T list

   val internal_term: T list -> term * T list

   val internal_fact: T list -> thm list * T list

   val internal_attribute: T list -> (morphism -> attribute) * T list

   val named_text: (string -> string) -> T list -> string * T list

   val named_typ: (string -> typ) -> T list -> typ * T list

   val named_term: (string -> term) -> T list -> term * T list

   val named_fact: (string -> thm list) -> T list -> thm list * T list

   val named_attribute: (string -> morphism -> attribute) -> T list ->

     (morphism -> attribute) * T list

   val typ_abbrev: Context.generic * T list -> typ * (Context.generic * T list)

   val typ: Context.generic * T list -> typ * (Context.generic * T list)

   val term: Context.generic * T list -> term * (Context.generic * T list)

   val term_abbrev: Context.generic * T list -> term * (Context.generic * T list)

   val prop: Context.generic * T list -> term * (Context.generic * T list)

   val tyname: Context.generic * T list -> string * (Context.generic * T list)

   val const: Context.generic * T list -> string * (Context.generic * T list)

   val const_proper: Context.generic * T list -> string * (Context.generic * T list)

   val bang_facts: Context.generic * T list -> thm list * (Context.generic * T list)

   val goal_spec: ((int -> tactic) -> tactic) -> ('a * T list)

     -> ((int -> tactic) -> tactic) * ('a * T list)

   val parse: OuterLex.token list -> T list * OuterLex.token list

   val parse1: (string -> bool) -> OuterLex.token list -> T list * OuterLex.token list

   val attribs: (string -> string) -> T list -> src list * T list

   val opt_attribs: (string -> string) -> T list -> src list * T list

   val thm_name: (string -> string) -> string -> T list -> (string * src list) * T list

   val opt_thm_name: (string -> string) -> string -> T list -> (string * src list) * T list

   val syntax: string -> ('b * T list -> 'a * ('b * T list)) -> src -> 'b -> 'a * 'b

   val context_syntax: string -> (Context.generic * T list -> 'a * (Context.generic * T list)) ->

     src -> Proof.context -> 'a * Proof.context

 end;

 structure Args: ARGS =

 struct

 structure T = OuterLex;

 structure P = OuterParse;

 (** datatype src **)

 type T = T.token;

 datatype src = Src of (string * 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 ProofContext.pretty_thm ctxt;

     fun prt arg =

       (case T.get_value arg of

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

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

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

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

       | _ => Pretty.str (T.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 (T.map_value

   (fn T.Text s => T.Text s

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

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

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

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

 fun maxidx_values (Src ((_, args), _)) = args |> fold (fn arg =>

   (case T.get_value arg of

     SOME (T.Typ T) => Term.maxidx_typ T

   | SOME (T.Term t) => Term.maxidx_term t

   | SOME (T.Fact ths) => fold Thm.maxidx_thm ths

   | _ => I));

 val assignable = map_args T.assignable;

 val closure = map_args T.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 P.not_eof --| atom;

 val ident = token

   (P.short_ident || P.long_ident || P.sym_ident || P.term_var ||

     P.type_ident || P.type_var || P.number);

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

 val alt_string = token P.alt_string;

 val symbolic = token P.keyword_ident_or_symbolic;

 fun $$$ x = (ident >> T.content_of || P.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 = named >> T.content_of;

 val alt_name = alt_string >> T.content_of;

 val symbol = symbolic >> T.content_of;

 val liberal_name = symbol || name;

 val var = (ident >> T.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 T.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 (T.assign (SOME (mk x)) arg; x) end;

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

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

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

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

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

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

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

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

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

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

 fun named_attribute att = internal_attribute || named >> evaluate T.Attribute (att o T.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 *)

 val tyname = Scan.peek (named_typ o ProofContext.read_tyname o Context.proof_of)

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

 val const = Scan.peek (named_term o ProofContext.read_const o Context.proof_of)

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

 val const_proper = Scan.peek (named_term o ProofContext.read_const_proper o Context.proof_of)

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

 (* improper method arguments *)

 val bang_facts = Scan.peek (fn context =>

   P.position ($$$ "!") >> (fn (_, pos) =>

     (warning ("use of prems in proof method" ^ Position.str_of pos);

       Assumption.prems_of (Context.proof_of context))) || Scan.succeed []);

 val from_to =

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

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

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

   $$$ "!" >> K ALLGOALS;

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

 fun goal_spec def = Scan.lift (Scan.optional goal def);

 (* arguments within outer syntax *)

 fun parse_args is_symid =

   let

     val keyword_symid = token (P.keyword_with is_symid);

     fun atom blk = P.group "argument"

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

         (if blk then token (P.$$$ ",") 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 (P.$$$ l) ::: P.!!! (args true @@@ (token (P.$$$ r) >> single))) x;

   in (args, args1) end;

 val parse = #1 (parse_args T.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 T.Text (intern o T.content_of);

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

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

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

 (* theorem specifications *)

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

 fun opt_thm_name intern s =

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

 (** syntax wrapper **)

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

   (case Scan.error (Scan.finite' T.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 T.unparse args')));

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

 end;