(*  Title:      Pure/Isar/local_theory.ML

     Author:     Makarius

 Local theory operations, with abstract target context.

 *)

 type local_theory = Proof.context;

 type generic_theory = Context.generic;

 signature LOCAL_THEORY =

 sig

   type operations

   val affirm: local_theory -> local_theory

   val naming_of: local_theory -> Name_Space.naming

   val full_name: local_theory -> binding -> string

   val map_naming: (Name_Space.naming -> Name_Space.naming) -> local_theory -> local_theory

   val conceal: local_theory -> local_theory

   val new_group: local_theory -> local_theory

   val reset_group: local_theory -> local_theory

   val restore_naming: local_theory -> local_theory -> local_theory

   val target_of: local_theory -> Proof.context

   val raw_theory_result: (theory -> 'a * theory) -> local_theory -> 'a * local_theory

   val raw_theory: (theory -> theory) -> local_theory -> local_theory

   val background_theory_result: (theory -> 'a * theory) -> local_theory -> 'a * local_theory

   val background_theory: (theory -> theory) -> local_theory -> local_theory

   val target_result: (Proof.context -> 'a * Proof.context) -> local_theory -> 'a * local_theory

   val target: (Proof.context -> Proof.context) -> local_theory -> local_theory

   val map_contexts: (Context.generic -> Context.generic) -> local_theory -> local_theory

   val propagate_ml_env: generic_theory -> generic_theory

   val standard_morphism: local_theory -> Proof.context -> morphism

   val target_morphism: local_theory -> morphism

   val global_morphism: local_theory -> morphism

   val define: (binding * mixfix) * (Attrib.binding * term) -> local_theory ->

     (term * (string * thm)) * local_theory

   val note: Attrib.binding * thm list -> local_theory -> (string * thm list) * local_theory

   val notes: (Attrib.binding * (thm list * Attrib.src list) list) list ->

     local_theory -> (string * thm list) list * local_theory

   val notes_kind: string -> (Attrib.binding * (thm list * Attrib.src list) list) list ->

     local_theory -> (string * thm list) list * local_theory

   val abbrev: Syntax.mode -> (binding * mixfix) * term -> local_theory ->

     (term * term) * local_theory

   val declaration: bool -> declaration -> local_theory -> local_theory

   val syntax_declaration: bool -> declaration -> local_theory -> local_theory

   val pretty: local_theory -> Pretty.T list

   val set_defsort: sort -> local_theory -> local_theory

   val type_notation: bool -> Syntax.mode -> (typ * mixfix) list -> local_theory -> local_theory

   val notation: bool -> Syntax.mode -> (term * mixfix) list -> local_theory -> local_theory

   val class_alias: binding -> class -> local_theory -> local_theory

   val type_alias: binding -> string -> local_theory -> local_theory

   val const_alias: binding -> string -> local_theory -> local_theory

   val init: serial option -> string -> operations -> Proof.context -> local_theory

   val restore: local_theory -> local_theory

   val exit: local_theory -> Proof.context

   val exit_global: local_theory -> theory

   val exit_result: (morphism -> 'a -> 'b) -> 'a * local_theory -> 'b * Proof.context

   val exit_result_global: (morphism -> 'a -> 'b) -> 'a * local_theory -> 'b * theory

 end;

 structure Local_Theory: LOCAL_THEORY =

 struct

 (** local theory data **)

 (* type lthy *)

 type operations =

  {define: (binding * mixfix) * (Attrib.binding * term) -> local_theory ->

     (term * (string * thm)) * local_theory,

   notes: string ->

     (Attrib.binding * (thm list * Attrib.src list) list) list ->

     local_theory -> (string * thm list) list * local_theory,

   abbrev: Syntax.mode -> (binding * mixfix) * term -> local_theory ->

     (term * term) * local_theory,

   declaration: bool -> declaration -> local_theory -> local_theory,

   syntax_declaration: bool -> declaration -> local_theory -> local_theory,

   pretty: local_theory -> Pretty.T list,

   exit: local_theory -> Proof.context};

 datatype lthy = LThy of

  {naming: Name_Space.naming,

   theory_prefix: string,

   operations: operations,

   target: Proof.context};

 fun make_lthy (naming, theory_prefix, operations, target) =

   LThy {naming = naming, theory_prefix = theory_prefix,

     operations = operations, target = target};

 (* context data *)

 structure Data = Proof_Data

 (

   type T = lthy option;

   fun init _ = NONE;

 );

 fun get_lthy lthy =

   (case Data.get lthy of

     NONE => error "No local theory context"

   | SOME (LThy data) => data);

 fun map_lthy f lthy =

   let val {naming, theory_prefix, operations, target} = get_lthy lthy

   in Data.put (SOME (make_lthy (f (naming, theory_prefix, operations, target)))) lthy end;

 val affirm = tap get_lthy;

 (* naming *)

 val naming_of = #naming o get_lthy;

 val full_name = Name_Space.full_name o naming_of;

 fun map_naming f = map_lthy (fn (naming, theory_prefix, operations, target) =>

   (f naming, theory_prefix, operations, target));

 val conceal = map_naming Name_Space.conceal;

 val new_group = map_naming Name_Space.new_group;

 val reset_group = map_naming Name_Space.reset_group;

 val restore_naming = map_naming o K o naming_of;

 (* target *)

 val target_of = #target o get_lthy;

 fun map_target f = map_lthy (fn (naming, theory_prefix, operations, target) =>

   (naming, theory_prefix, operations, f target));

 (* substructure mappings *)

 fun raw_theory_result f lthy =

   let

     val (res, thy') = f (Proof_Context.theory_of lthy);

     val lthy' = lthy

       |> map_target (Proof_Context.transfer thy')

       |> Proof_Context.transfer thy';

   in (res, lthy') end;

 fun raw_theory f = #2 o raw_theory_result (f #> pair ());

 val checkpoint = raw_theory Theory.checkpoint;

 fun background_theory_result f lthy =

   lthy |> raw_theory_result (fn thy =>

     thy

     |> Sign.map_naming (K (naming_of lthy))

     |> f

     ||> Sign.restore_naming thy

     ||> Theory.checkpoint);

 fun background_theory f = #2 o background_theory_result (f #> pair ());

 fun target_result f lthy =

   let

     val (res, ctxt') = target_of lthy

       |> Context_Position.set_visible false

       |> f

       ||> Context_Position.restore_visible lthy;

     val thy' = Proof_Context.theory_of ctxt';

     val lthy' = lthy

       |> map_target (K ctxt')

       |> Proof_Context.transfer thy';

   in (res, lthy') end;

 fun target f = #2 o target_result (f #> pair ());

 fun map_contexts f =

   background_theory (Context.theory_map f) #>

   target (Context.proof_map f) #>

   Context.proof_map f;

 fun propagate_ml_env (context as Context.Proof lthy) =

       Context.Proof (map_contexts (ML_Env.inherit context) lthy)

   | propagate_ml_env context = context;

 (* morphisms *)

 fun standard_morphism lthy ctxt =

   Proof_Context.norm_export_morphism lthy ctxt $>

   Morphism.binding_morphism (Name_Space.transform_binding (naming_of lthy));

 fun target_morphism lthy = standard_morphism lthy (target_of lthy);

 fun global_morphism lthy =

   standard_morphism lthy (Proof_Context.init_global (Proof_Context.theory_of lthy));

 (* primitive operations *)

 fun operation f lthy = f (#operations (get_lthy lthy)) lthy;

 fun operation1 f x = operation (fn ops => f ops x);

 fun operation2 f x y lthy = operation (fn ops => f ops x y) lthy;

 val pretty = operation #pretty;

 val abbrev = apsnd checkpoint ooo operation2 #abbrev;

 val define = apsnd checkpoint oo operation1 #define;

 val notes_kind = apsnd checkpoint ooo operation2 #notes;

 val declaration = checkpoint ooo operation2 #declaration;

 val syntax_declaration = checkpoint ooo operation2 #syntax_declaration;

 (** basic derived operations **)

 val notes = notes_kind "";

 fun note (a, ths) = notes [(a, [(ths, [])])] #>> the_single;

 fun set_defsort S =

   syntax_declaration false (K (Context.mapping (Sign.set_defsort S) (Proof_Context.set_defsort S)));

 (* notation *)

 fun type_notation add mode raw_args lthy =

   let val args = map (apfst (Morphism.typ (target_morphism lthy))) raw_args

   in syntax_declaration false (Proof_Context.target_type_notation add mode args) lthy end;

 fun notation add mode raw_args lthy =

   let val args = map (apfst (Morphism.term (target_morphism lthy))) raw_args

   in syntax_declaration false (Proof_Context.target_notation add mode args) lthy end;

 (* name space aliases *)

 fun alias global_alias local_alias b name =

   syntax_declaration false (fn phi =>

     let val b' = Morphism.binding phi b

     in Context.mapping (global_alias b' name) (local_alias b' name) end)

   #> local_alias b name;

 val class_alias = alias Sign.class_alias Proof_Context.class_alias;

 val type_alias = alias Sign.type_alias Proof_Context.type_alias;

 val const_alias = alias Sign.const_alias Proof_Context.const_alias;

 (** init and exit **)

 (* init *)

 fun init group theory_prefix operations target =

   let val naming =

     Sign.naming_of (Proof_Context.theory_of target)

     |> Name_Space.set_group group

     |> Name_Space.mandatory_path theory_prefix;

   in

     target |> Data.map

       (fn NONE => SOME (make_lthy (naming, theory_prefix, operations, target))

         | SOME _ => error "Local theory already initialized")

     |> checkpoint

   end;

 fun restore lthy =

   let val {naming, theory_prefix, operations, target} = get_lthy lthy

   in init (Name_Space.get_group naming) theory_prefix operations target end;

 (* exit *)

 val exit = Proof_Context.background_theory Theory.checkpoint o operation #exit;

 val exit_global = Proof_Context.theory_of o exit;

 fun exit_result f (x, lthy) =

   let

     val ctxt = exit lthy;

     val phi = standard_morphism lthy ctxt;

   in (f phi x, ctxt) end;

 fun exit_result_global f (x, lthy) =

   let

     val thy = exit_global lthy;

     val thy_ctxt = Proof_Context.init_global thy;

     val phi = standard_morphism lthy thy_ctxt;

   in (f phi x, thy) end;

 end;