(*  Title:      Pure/Isar/args.ML

     ID:         $Id$

     Author:     Markus Wenzel, TU Muenchen

 Concrete argument syntax of attributes, methods etc. -- with special

 support for embedded values and static binding.

 *)

 signature ARGS =

 sig

   datatype value =

     Text of string | Typ of typ | Term of term | Fact of thm list |

     Attribute of morphism -> attribute

   type T

   val string_of: T -> string

   val mk_ident: string * Position.T -> T

   val mk_string: string * Position.T -> T

   val mk_alt_string: string * Position.T -> T

   val mk_keyword: string * Position.T -> T

   val mk_text: string -> T

   val mk_typ: typ -> T

   val mk_term: term -> T

   val mk_fact: thm list -> T

   val mk_attribute: (morphism -> attribute) -> T

   val stopper: T * (T -> bool)

   val not_eof: T -> bool

   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 assign: value option -> T -> unit

   val closure: src -> src

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

   val !!! : (T list -> 'a) -> T list -> 'a

   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 terminator: T list -> T * 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 nat: T list -> int * T list

   val int: T list -> int * T list

   val var: T list -> indexname * T list

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

   val list1: (T list -> 'a * T list) -> T list -> 'a list * T list

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

   val enum1: string -> ('a * T list -> 'b * ('a * T list)) -> 'a * T list -> 'b list * ('a * T list)

   val and_list: ('a * T list -> 'b * ('a * T list)) -> 'a * T list -> 'b list * ('a * T list)

   val and_list1: ('a * T list -> 'b * ('a * T list)) -> 'a * T list -> 'b list * ('a * T list)

   val ahead: T list -> T * 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 thm_sel: T list -> Facts.interval list * 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 attribs: (string -> string) -> T list -> src list * T list

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

 (** datatype T **)

 (*An argument token is a symbol (with raw string value), together with

   an optional assigned internal value.  Note that an assignable ref

   designates an intermediate state of internalization -- it is NOT

   meant to persist.*)

 datatype kind = Ident | String | AltString | Keyword | EOF;

 type symbol = kind * string * Position.T;

 datatype value =

   Text of string |

   Typ of typ |

   Term of term |

   Fact of thm list |

   Attribute of morphism -> attribute;

 datatype slot =

   Empty |

   Value of value option |

   Assignable of value option ref;

 datatype T = Arg of symbol * slot;

 fun string_of (Arg ((Ident, x, _), _)) = x

   | string_of (Arg ((String, x, _), _)) = quote x

   | string_of (Arg ((AltString, x, _), _)) = enclose "`" "`" x

   | string_of (Arg ((Keyword, x, _), _)) = x

   | string_of (Arg ((EOF, _, _), _)) = "";

 fun sym_of (Arg ((_, x, _), _)) = x;

 fun pos_of (Arg ((_, _, pos), _)) = pos;

 (* basic constructors *)

 fun mk_symbol k (x, p) = Arg ((k, x, p), Empty);

 fun mk_value k v = Arg ((Keyword, k, Position.none), Value (SOME v));

 val mk_ident = mk_symbol Ident;

 val mk_string = mk_symbol String;

 val mk_alt_string = mk_symbol AltString;

 val mk_keyword = mk_symbol Keyword;

 val mk_text = mk_value "<text>" o Text;

 val mk_typ = mk_value "<typ>" o Typ;

 val mk_term = mk_value "<term>" o Term;

 val mk_fact = mk_value "<fact>" o Fact;

 val mk_attribute = mk_value "<attribute>" o Attribute;

 (* eof *)

 val eof = mk_symbol EOF ("", Position.none);

 fun is_eof (Arg ((EOF, _, _), _)) = true

   | is_eof _ = false;

 val stopper = (eof, is_eof);

 val not_eof = not o is_eof;

 (** datatype src **)

 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 (_, Value (SOME (Text s)))) = Pretty.str (quote s)

       | prt (Arg (_, Value (SOME (Typ T)))) = Syntax.pretty_typ ctxt T

       | prt (Arg (_, Value (SOME (Term t)))) = Syntax.pretty_term ctxt t

       | prt (Arg (_, Value (SOME (Fact ths)))) =

           Pretty.enclose "(" ")" (Pretty.breaks (map prt_thm ths))

       | prt arg = Pretty.str (string_of 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 map_value f (Arg (s, Value (SOME v))) = Arg (s, Value (SOME (f v)))

   | map_value _ arg = arg;

 fun morph_values phi = map_args (map_value

   (fn Text s => Text s

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

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

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

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

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

   (fn (Arg (_, Value (SOME (Typ T)))) => Term.maxidx_typ T

     | (Arg (_, Value (SOME (Term t)))) => Term.maxidx_term t

     | (Arg (_, Value (SOME (Fact ths)))) => fold Thm.maxidx_thm ths

     | _ => I);

 (* static binding *)

 (*1st stage: make empty slots assignable*)

 val assignable =

   map_args (fn Arg (s, Empty) => Arg (s, Assignable (ref NONE)) | arg => arg);

 (*2nd stage: assign values as side-effect of scanning*)

 fun assign v (arg as Arg (_, Assignable r)) = r := v

   | assign _ _ = ();

 val ahead = Scan.ahead (Scan.one not_eof);

 fun touch scan = ahead -- scan >> (fn (arg, y) => (assign NONE arg; y));

 (*3rd stage: static closure of final values*)

 val closure =

   map_args (fn Arg (s, Assignable (ref v)) => Arg (s, Value v) | arg => arg);

 (** scanners **)

 (* position *)

 fun position scan =

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

 (* cut *)

 fun !!! scan =

   let

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

       | get_pos (arg :: _) = Position.str_of (pos_of arg);

     fun err (args, NONE) = "Argument syntax error" ^ get_pos args

       | err (args, SOME msg) = "Argument syntax error" ^ get_pos args ^ ": " ^ msg;

   in Scan.!! err scan end;

 (* basic *)

 fun some_ident f =

   touch (Scan.some (fn Arg ((Ident, x, _), _) => f x | _ => NONE));

 val named =

   touch (Scan.one (fn Arg ((k, _, _), _) => k = Ident orelse k = String));

 val alt_string =

   touch (Scan.one (fn Arg ((k, _, _), _) => k = AltString));

 val symbolic =

   touch (Scan.one (fn Arg ((k, x, _), _) => k = Keyword andalso OuterLex.is_sid x));

 fun &&& x =

   touch (Scan.one (fn Arg ((k, y, _), _) => k = Keyword andalso x = y));

 fun $$$ x =

   touch (Scan.one (fn Arg ((k, y, _), _) => (k = Ident orelse k = Keyword) andalso x = y))

   >> sym_of;

 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 terminator = Scan.ahead (Scan.one is_eof);

 val name = named >> sym_of;

 val alt_name = alt_string >> sym_of;

 val symbol = symbolic >> sym_of;

 val liberal_name = symbol || name;

 val nat = some_ident Lexicon.read_nat;

 val int = Scan.optional ($$$ "-" >> K ~1) 1 -- nat >> op *;

 val var = some_ident Lexicon.read_variable;

 (* enumerations *)

 fun list1 scan = scan ::: Scan.repeat ($$$ "," |-- scan);

 fun list scan = list1 scan || Scan.succeed [];

 fun enum1 sep scan = scan ::: Scan.repeat (Scan.lift ($$$ sep) |-- scan);

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

 fun and_list1 scan = enum1 "and" scan;

 fun and_list scan = enum "and" scan;

 (* values *)

 fun value dest = Scan.some  (*no touch here*)

   (fn Arg (_, Value (SOME v)) => (SOME (dest v) handle Match => NONE)

     | Arg _ => NONE);

 fun evaluate mk eval arg =

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

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

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

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

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

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

 fun named_text intern = internal_text || named >> evaluate Text intern;

 fun named_typ readT = internal_typ || named >> evaluate Typ readT;

 fun named_term read = internal_term || named >> evaluate Term read;

 fun named_fact get = internal_fact || (alt_string || named) >> evaluate Fact get;

 fun named_attribute att = internal_attribute || named >> evaluate Attribute att;

 (* 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 | _ => "");

 (* misc *)

 val thm_sel = parens (list1

  (nat --| $$$ "-" -- nat >> Facts.FromTo ||

   nat --| $$$ "-" >> Facts.From ||

   nat >> Facts.Single));

 val bang_facts = Scan.peek (fn context =>

   $$$ "!" >> (fn _ => (warning "use of prems in proof method";

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

 (* goal specification *)

 (* range *)

 val from_to =

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

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

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

   $$$ "!" >> K ALLGOALS;

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

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

 (* attribs *)

 local

 val exclude = member (op =) (explode "()[],");

 fun atomic blk = touch (Scan.one (fn Arg ((k, x, _), _) =>

     k <> Keyword orelse not (exclude x) orelse blk andalso x = ","));

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

 and args1 blk x =

   ((Scan.repeat1

     (Scan.repeat1 (atomic blk) ||

       argsp "(" ")" ||

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

 and argsp l r x =

   (Scan.trace (&&& l -- !!! (args true -- &&& r)) >> #2) x;

 in

 fun attribs intern =

   let

     val attrib_name = internal_text || (symbolic || named) >> evaluate Text intern;

     val attrib = position (attrib_name -- !!! (args false)) >> src;

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

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

 end;

 (* syntax interface *)

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

   (case Scan.error (Scan.finite' 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 string_of args')));

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

 end;