(*  Title:      Pure/Isar/attrib.ML

     ID:         $Id$

     Author:     Markus Wenzel, TU Muenchen

 Symbolic representation of attributes -- with name and syntax.

 *)

 signature BASIC_ATTRIB =

 sig

   val print_attributes: theory -> unit

 end;

 signature ATTRIB =

 sig

   include BASIC_ATTRIB

   type src

   exception ATTRIB_FAIL of (string * Position.T) * exn

   val intern: theory -> xstring -> string

   val intern_src: theory -> src -> src

   val pretty_attribs: Proof.context -> src list -> Pretty.T list

   val attribute: theory -> src -> attribute

   val attribute_i: theory -> src -> attribute

   val map_specs: ('a -> 'att) ->

     (('c * 'a list) * 'd) list -> (('c * 'att list) * 'd) list

   val map_facts: ('a -> 'att) ->

     (('c * 'a list) * ('d * 'a list) list) list ->

     (('c * 'att list) * ('d * 'att list) list) list

   val crude_closure: Proof.context -> src -> src

   val add_attributes: (bstring * (src -> attribute) * string) list -> theory -> theory

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

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

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

   val syntax: (Context.generic * Args.T list ->

     attribute * (Context.generic * Args.T list)) -> src -> attribute

   val no_args: attribute -> src -> attribute

   val add_del_args: attribute -> attribute -> src -> attribute

   val internal: (morphism -> attribute) -> src

 end;

 structure Attrib: ATTRIB =

 struct

 type src = Args.src;

 (** named attributes **)

 (* theory data *)

 structure AttributesData = TheoryDataFun

 (

   type T = (((src -> attribute) * string) * stamp) NameSpace.table;

   val empty = NameSpace.empty_table;

   val copy = I;

   val extend = I;

   fun merge _ tables = NameSpace.merge_tables (eq_snd (op =)) tables handle Symtab.DUPS dups =>

     error ("Attempt to merge different versions of attribute(s) " ^ commas_quote dups);

 );

 fun print_attributes thy =

   let

     val attribs = AttributesData.get thy;

     fun prt_attr (name, ((_, comment), _)) = Pretty.block

       [Pretty.str (name ^ ":"), Pretty.brk 2, Pretty.str comment];

   in

     [Pretty.big_list "attributes:" (map prt_attr (NameSpace.extern_table attribs))]

     |> Pretty.chunks |> Pretty.writeln

   end;

 (* name space *)

 val intern = NameSpace.intern o #1 o AttributesData.get;

 val intern_src = Args.map_name o intern;

 val extern = NameSpace.extern o #1 o AttributesData.get o ProofContext.theory_of;

 (* pretty printing *)

 fun pretty_attribs _ [] = []

   | pretty_attribs ctxt srcs =

       [Pretty.enclose "[" "]"

         (Pretty.commas (map (Args.pretty_src ctxt o Args.map_name (extern ctxt)) srcs))];

 (* get attributes *)

 exception ATTRIB_FAIL of (string * Position.T) * exn;

 fun attribute_i thy =

   let

     val attrs = #2 (AttributesData.get thy);

     fun attr src =

       let val ((name, _), pos) = Args.dest_src src in

         (case Symtab.lookup attrs name of

           NONE => error ("Unknown attribute: " ^ quote name ^ Position.str_of pos)

         | SOME ((att, _), _) => transform_failure (curry ATTRIB_FAIL (name, pos)) (att src))

       end;

   in attr end;

 fun attribute thy = attribute_i thy o intern_src thy;

 (* attributed declarations *)

 fun map_specs f = map (apfst (apsnd (map f)));

 fun map_facts f = map (apfst (apsnd (map f)) o apsnd (map (apsnd (map f))));

 (* crude_closure *)

 (*Produce closure without knowing facts in advance! The following

   works reasonably well for attribute parsers that do not peek at the

   thm structure.*)

 fun crude_closure ctxt src =

  (try (fn () => attribute_i (ProofContext.theory_of ctxt) src

     (Context.Proof ctxt, Drule.asm_rl)) ();

   Args.closure src);

 (* add_attributes *)

 fun add_attributes raw_attrs thy =

   let

     val new_attrs =

       raw_attrs |> map (fn (name, att, comment) => (name, ((att, comment), stamp ())));

     fun add attrs = NameSpace.extend_table (Sign.naming_of thy) (attrs, new_attrs)

       handle Symtab.DUPS dups =>

         error ("Duplicate declaration of attributes(s) " ^ commas_quote dups);

   in AttributesData.map add thy end;

 (** attribute parsers **)

 (* tags *)

 fun tag x = Scan.lift (Args.name -- Scan.repeat Args.name) x;

 (* theorems *)

 local

 val get_thms = Context.cases PureThy.get_thms ProofContext.get_thms;

 val fact_name = Args.internal_fact >> K "<fact>" || Args.name;

 fun gen_thm pick = Scan.depend (fn st =>

  (Scan.ahead Args.alt_name -- Args.named_fact (get_thms st o Fact)

     >> (fn (s, fact) => ("", Fact s, fact)) ||

   Scan.ahead fact_name -- Args.named_fact (get_thms st o Name) -- Args.thm_sel

     >> (fn ((name, fact), sel) => (name, NameSelection (name, sel), fact)) ||

   Scan.ahead fact_name -- Args.named_fact (get_thms st o Name)

     >> (fn (name, fact) => (name, Name name, fact))) --

   Args.opt_attribs (intern (Context.theory_of st))

   >> (fn ((name, thmref, fact), srcs) =>

     let

       val ths = PureThy.select_thm thmref fact;

       val atts = map (attribute_i (Context.theory_of st)) srcs;

       val (st', ths') = foldl_map (Library.apply atts) (st, ths);

     in (st', pick name ths') end));

 in

 val thm = gen_thm PureThy.single_thm;

 val multi_thm = gen_thm (K I);

 val thms = Scan.repeat multi_thm >> flat;

 end;

 (** attribute syntax **)

 fun syntax scan src (st, th) =

   let val (f, st') = Args.syntax "attribute" scan src st

   in f (st', th) end;

 fun no_args x = syntax (Scan.succeed x);

 fun add_del_args add del x = syntax

   (Scan.lift (Args.add >> K add || Args.del >> K del || Scan.succeed add)) x;

 (** basic attributes **)

 (* tags *)

 fun tagged x = syntax (tag >> PureThy.tag) x;

 fun untagged x = syntax (Scan.lift Args.name >> PureThy.untag) x;

 fun kind x = syntax (Scan.lift Args.name >> PureThy.kind) x;

 (* rule composition *)

 val COMP_att =

   syntax (Scan.lift (Scan.optional (Args.bracks Args.nat) 1) -- thm

     >> (fn (i, B) => Thm.rule_attribute (fn _ => fn A => Drule.compose_single (A, i, B))));

 val THEN_att =

   syntax (Scan.lift (Scan.optional (Args.bracks Args.nat) 1) -- thm

     >> (fn (i, B) => Thm.rule_attribute (fn _ => fn A => A RSN (i, B))));

 val OF_att =

   syntax (thms >> (fn Bs => Thm.rule_attribute (fn _ => fn A => Bs MRS A)));

 (* rename_abs *)

 fun rename_abs src = syntax

   (Scan.lift (Scan.repeat (Args.maybe Args.name) >> (apsnd o Drule.rename_bvars'))) src;

 (* unfold / fold definitions *)

 fun unfolded_syntax rule =

   syntax (thms >>

     (fn ths => Thm.rule_attribute (fn context => rule (Context.proof_of context) ths)));

 val unfolded = unfolded_syntax LocalDefs.unfold;

 val folded = unfolded_syntax LocalDefs.fold;

 (* rule cases *)

 fun consumes x = syntax (Scan.lift (Scan.optional Args.nat 1) >> RuleCases.consumes) x;

 fun case_names x = syntax (Scan.lift (Scan.repeat1 Args.name) >> RuleCases.case_names) x;

 fun case_conclusion x =

   syntax (Scan.lift (Args.name -- Scan.repeat Args.name) >> RuleCases.case_conclusion) x;

 fun params x = syntax (Args.and_list1 (Scan.lift (Scan.repeat Args.name)) >> RuleCases.params) x;

 (* rule format *)

 fun rule_format_att x = syntax (Args.mode "no_asm"

   >> (fn true => ObjectLogic.rule_format_no_asm | false => ObjectLogic.rule_format)) x;

 fun elim_format x = no_args (Thm.rule_attribute (K Tactic.make_elim)) x;

 (* misc rules *)

 fun standard x = no_args (Thm.rule_attribute (K Drule.standard)) x;

 fun no_vars x = no_args (Thm.rule_attribute (fn ctxt => fn th =>

   let val ((_, [th']), _) = Variable.import_thms true [th] (Context.proof_of ctxt)

   in th' end)) x;

 fun eta_long x =

   no_args (Thm.rule_attribute (K (Conv.fconv_rule Drule.eta_long_conversion))) x;

 (* internal attribute *)

 fun internal att = Args.src (("Pure.attribute", [Args.mk_attribute att]), Position.none);

 fun internal_att x =

   syntax (Scan.lift Args.internal_attribute >> Morphism.form) x;

 (* theory setup *)

 val _ = Context.add_setup

  (add_attributes

    [("tagged", tagged, "tagged theorem"),

     ("untagged", untagged, "untagged theorem"),

     ("kind", kind, "theorem kind"),

     ("COMP", COMP_att, "direct composition with rules (no lifting)"),

     ("THEN", THEN_att, "resolution with rule"),

     ("OF", OF_att, "rule applied to facts"),

     ("rename_abs", rename_abs, "rename bound variables in abstractions"),

     ("unfolded", unfolded, "unfolded definitions"),

     ("folded", folded, "folded definitions"),

     ("standard", standard, "result put into standard form"),

     ("elim_format", elim_format, "destruct rule turned into elimination rule format"),

     ("no_vars", no_vars, "frozen schematic vars"),

     ("eta_long", eta_long, "put theorem into eta long beta normal form"),

     ("consumes", consumes, "number of consumed facts"),

     ("case_names", case_names, "named rule cases"),

     ("case_conclusion", case_conclusion, "named conclusion of rule cases"),

     ("params", params, "named rule parameters"),

     ("atomize", no_args ObjectLogic.declare_atomize, "declaration of atomize rule"),

     ("rulify", no_args ObjectLogic.declare_rulify, "declaration of rulify rule"),

     ("rule_format", rule_format_att, "result put into standard rule format"),

     ("defn", add_del_args LocalDefs.defn_add LocalDefs.defn_del,

       "declaration of definitional transformations"),

     ("attribute", internal_att, "internal attribute")]);

 end;

 structure BasicAttrib: BASIC_ATTRIB = Attrib;

 open BasicAttrib;