signature QUOTIENT_INFO =

sig

  exception NotFound

  type maps_info = {mapfun: string, relmap: string}

  val maps_exists: theory -> string -> bool

  val maps_lookup: theory -> string -> maps_info     (* raises NotFound *)

  val maps_update_thy: string -> maps_info -> theory -> theory    

  val maps_update: string -> maps_info -> Proof.context -> Proof.context     

  val print_mapsinfo: Proof.context -> unit

  type quotdata_info = {qtyp: typ, rtyp: typ, equiv_rel: term, equiv_thm: thm}

  val transform_quotdata: morphism -> quotdata_info -> quotdata_info

  val quotdata_lookup: theory -> string -> quotdata_info     (* raises NotFound *)

  val quotdata_update_thy: string -> quotdata_info -> theory -> theory

  val quotdata_update_gen: string -> quotdata_info -> Context.generic -> Context.generic

  val print_quotinfo: Proof.context -> unit

  type qconsts_info = {qconst: term, rconst: term, def: thm}

  val transform_qconsts: morphism -> qconsts_info -> qconsts_info

  val qconsts_lookup: theory -> term -> qconsts_info     (* raises NotFound *)

  val qconsts_dest: theory -> qconsts_info list

  val print_qconstinfo: Proof.context -> unit

  val equiv_rules_get: Proof.context -> thm list

  val equiv_rules_add: attribute

  val rsp_rules_get: Proof.context -> thm list  

  val prs_rules_get: Proof.context -> thm list  

  val id_simps_get: Proof.context -> thm list

  val quotient_rules_get: Proof.context -> thm list

  val quotient_rules_add: attribute

end;

functor Filtered_Named_Thms (val name: string val description: string val filter: thm -> thm): NAMED_THMS =

struct

structure Data = Generic_Data

( type T = thm Item_Net.T;

  val empty = Thm.full_rules;

  val extend = I;

  val merge = Item_Net.merge);

val content = Item_Net.content o Data.get;

val get = content o Context.Proof;

val add_thm = Data.map o Item_Net.update o filter;

val del_thm = Data.map o Item_Net.remove;

val add = Thm.declaration_attribute add_thm;

val del = Thm.declaration_attribute del_thm;

val setup =

  Attrib.setup (Binding.name name) (Attrib.add_del add del) ("declaration of " ^ description) #>

  PureThy.add_thms_dynamic (Binding.name name, content);

end;

structure Quotient_Info: QUOTIENT_INFO =

struct

exception NotFound

(** data containers **)

(* info about map- and rel-functions for a type *)

type maps_info = {mapfun: string, relmap: string}

structure MapsData = Theory_Data

  (type T = maps_info Symtab.table

   val empty = Symtab.empty

   val extend = I

   val merge = Symtab.merge (K true))

fun maps_exists thy s = 

  case (Symtab.lookup (MapsData.get thy) s) of

    SOME _ => true

  | NONE => false

fun maps_lookup thy s = 

  case (Symtab.lookup (MapsData.get thy) s) of

    SOME map_fun => map_fun

  | NONE => raise NotFound

fun maps_update_thy k minfo = MapsData.map (Symtab.update (k, minfo))

fun maps_update k minfo = ProofContext.theory (maps_update_thy k minfo)

fun maps_attribute_aux s minfo = Thm.declaration_attribute 

  (fn _ => Context.mapping (maps_update_thy s minfo) (maps_update s minfo))

(* attribute to be used in declare statements *)

fun maps_attribute (ctxt, (tystr, (mapstr, relstr))) = 

let  

  val thy = ProofContext.theory_of ctxt

  val tyname = Sign.intern_type thy tystr

  val mapname = Sign.intern_const thy mapstr

  val relname = Sign.intern_const thy relstr

  fun sanity_check s = (Const (s, dummyT) |> Syntax.check_term ctxt)

  val _ =  map sanity_check [mapname, relname]

in

  maps_attribute_aux tyname {mapfun = mapname, relmap = relname}

end

val maps_attr_parser = 

      Args.context -- Scan.lift

       ((Args.name --| OuterParse.$$$ "=") -- 

         (OuterParse.$$$ "(" |-- Args.name --| OuterParse.$$$ "," -- 

           Args.name --| OuterParse.$$$ ")"))

val _ = Context.>> (Context.map_theory

         (Attrib.setup @{binding "map"} (maps_attr_parser >> maps_attribute) 

           "declaration of map information"))

fun print_mapsinfo ctxt =

let

  fun prt_map (ty_name, {mapfun, relmap}) = 

      Pretty.block (Library.separate (Pretty.brk 2)

        (map Pretty.str 

          ["type:", ty_name,

           "map:", mapfun,

           "relation map:", relmap]))

in

  MapsData.get (ProofContext.theory_of ctxt)

  |> Symtab.dest

  |> map (prt_map)

  |> Pretty.big_list "maps for type constructors:" 

  |> Pretty.writeln

end

(* info about quotient types *)

type quotdata_info = {qtyp: typ, rtyp: typ, equiv_rel: term, equiv_thm: thm}

structure QuotData = Theory_Data

  (type T = quotdata_info Symtab.table

   val empty = Symtab.empty

   val extend = I

   val merge = Symtab.merge (K true)) 

fun transform_quotdata phi {qtyp, rtyp, equiv_rel, equiv_thm} =

    {qtyp = Morphism.typ phi qtyp,

     rtyp = Morphism.typ phi rtyp,

     equiv_rel = Morphism.term phi equiv_rel,

     equiv_thm = Morphism.thm phi equiv_thm}

fun quotdata_lookup thy str = 

  case Symtab.lookup (QuotData.get thy) str of

    SOME qinfo => qinfo

  | NONE => raise NotFound

fun quotdata_update_thy str qinfo = QuotData.map (Symtab.update (str, qinfo))

fun quotdata_update_gen str qinfo = Context.mapping (quotdata_update_thy str qinfo) I

fun print_quotinfo ctxt =

let

  fun prt_quot {qtyp, rtyp, equiv_rel, equiv_thm} = 

      Pretty.block (Library.separate (Pretty.brk 2)

          [Pretty.str "quotient type:", 

           Syntax.pretty_typ ctxt qtyp,

           Pretty.str "raw type:", 

           Syntax.pretty_typ ctxt rtyp,

           Pretty.str "relation:", 

           Syntax.pretty_term ctxt equiv_rel,

           Pretty.str "equiv. thm:", 

           Syntax.pretty_term ctxt (prop_of equiv_thm)])

in

  QuotData.get (ProofContext.theory_of ctxt)

  |> Symtab.dest

  |> map (prt_quot o snd)

  |> Pretty.big_list "quotients:" 

  |> Pretty.writeln

end

(* info about quotient constants *)

type qconsts_info = {qconst: term, rconst: term, def: thm}

structure QConstsData = Theory_Data

   val extend = I

fun transform_qconsts phi {qconst, rconst, def} =

    {qconst = Morphism.term phi qconst,

     rconst = Morphism.term phi rconst,

     def = Morphism.thm phi def}

fun qconsts_dest thy =

(* FIXME / TODO : better implementation of the lookup datastructure *)

(* for example symtabs to alist; or tables with string type key     *) 

fun qconsts_lookup thy t =

  let

    val (name, qty) = dest_Const t

    fun matches (_, x) =

      let

        val (name', qty') = dest_Const (#qconst x);

      in

        name = name' andalso Sign.typ_instance thy (qty, qty')

      end

  in

    case (find_first matches smt) of

      SOME (_, x) => x

    | _ => raise NotFound

  end

fun print_qconstinfo ctxt =

let

  fun prt_qconst {qconst, rconst, def} =

      Pretty.block (separate (Pretty.brk 1)

          [Syntax.pretty_term ctxt qconst,

           Pretty.str ":=",

           Syntax.pretty_term ctxt rconst,

           Pretty.str "as",

           Syntax.pretty_term ctxt (prop_of def)])

in

  QConstsData.get (ProofContext.theory_of ctxt)

  |> map (prt_qconst o snd)

  |> Pretty.big_list "quotient constants:" 

  |> Pretty.writeln

end

(* FIXME/TODO: check the various lemmas conform *)

(* with the required shape                      *)

(* equivalence relation theorems *)

structure EquivRules = Named_Thms

  (val name = "quot_equiv"

   val description = "Equivalence relation theorems.")

val equiv_rules_get = EquivRules.get

val equiv_rules_add = EquivRules.add

(* respectfulness theorems *)

structure RspRules = Filtered_Named_Thms

  (val name = "quot_respect"

   val description = "Respectfulness theorems."

   val filter = I)

val rsp_rules_get = RspRules.get

(* preservation theorems *)

structure PrsRules = Named_Thms

  (val name = "quot_preserve"

   val description = "Preservation theorems.")

val prs_rules_get = PrsRules.get

(* id simplification theorems *)

structure IdSimps = Named_Thms

  (val name = "id_simps"

   val description = "Identity simp rules for maps.")

val id_simps_get = IdSimps.get

(* quotient theorems *)

structure QuotientRules = Named_Thms

  (val name = "quot_thm"

   val description = "Quotient theorems.")

val quotient_rules_get = QuotientRules.get

val quotient_rules_add = QuotientRules.add

(* setup of the theorem lists *)

val _ = Context.>> (Context.map_theory 

    (EquivRules.setup #>

     RspRules.setup #>

     PrsRules.setup #>

     IdSimps.setup #>

     QuotientRules.setup))

(* setup of the printing commands *)

fun improper_command (pp_fn, cmd_name, descr_str) =  

  OuterSyntax.improper_command cmd_name descr_str 

    OuterKeyword.diag (Scan.succeed (Toplevel.keep (pp_fn o Toplevel.context_of)))

val _ = map improper_command 

         [(print_mapsinfo, "print_maps", "prints out all map functions"),

          (print_quotinfo, "print_quotients", "prints out all quotients"), 

          (print_qconstinfo, "print_quotconsts", "prints out all quotient constants")]

end; (* structure *)