(*  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

  val Attribute: bstring -> (Args.src -> attribute) -> string -> 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

(struct

  val name = "Isar/attributes";

  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 _ attribs =

    let

      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;

end);

val _ = Context.add_setup AttributesData.init;

val print_attributes = AttributesData.print;

(* 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;

fun Attribute name att cmt = Context.>> (add_attributes [(name, att, cmt)]);

(** 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 (st', f) = 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 true [th] (Context.proof_of ctxt)

  in th' end)) x;

fun eta_long x = no_args (Thm.rule_attribute (K (Drule.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 >> (fn att => att Morphism.identity)) 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;