(* Title: Pure/context.ML
Author: Markus Wenzel, TU Muenchen
Generic theory contexts with unique identity, arbitrarily typed data,
monotonic development graph and history support. Generic proof
contexts with arbitrarily typed data.
Firm naming conventions:
thy, thy', thy1, thy2: theory
ctxt, ctxt', ctxt1, ctxt2: Proof.context
context: Context.generic
*)
signature BASIC_CONTEXT =
sig
type theory
exception THEORY of string * theory list
structure Proof: sig type context end
structure Proof_Context:
sig
val theory_of: Proof.context -> theory
val init_global: theory -> Proof.context
val get_global: {long: bool} -> theory -> string -> Proof.context
end
end;
signature CONTEXT =
sig
include BASIC_CONTEXT
(*theory data*)
type data_kind = int
val data_kinds: unit -> (data_kind * Position.T) list
(*theory context*)
type id = int
type theory_id
val theory_id: theory -> theory_id
val data_timing: bool Unsynchronized.ref
val parents_of: theory -> theory list
val ancestors_of: theory -> theory list
val theory_id_ord: theory_id ord
val theory_id_name: {long: bool} -> theory_id -> string
val theory_long_name: theory -> string
val theory_base_name: theory -> string
val theory_name: {long: bool} -> theory -> string
val theory_identifier: theory -> id
val PureN: string
val pretty_thy: theory -> Pretty.T
val pretty_abbrev_thy: theory -> Pretty.T
val get_theory: {long: bool} -> theory -> string -> theory
val eq_thy_id: theory_id * theory_id -> bool
val eq_thy: theory * theory -> bool
val proper_subthy_id: theory_id * theory_id -> bool
val proper_subthy: theory * theory -> bool
val subthy_id: theory_id * theory_id -> bool
val subthy: theory * theory -> bool
val join_thys: theory list -> theory
val begin_thy: string -> theory list -> theory
val finish_thy: theory -> theory
val theory_data_sizeof1: theory -> (Position.T * int) list
(*proof context*)
val raw_transfer: theory -> Proof.context -> Proof.context
(*certificate*)
datatype certificate = Certificate of theory | Certificate_Id of theory_id
val certificate_theory: certificate -> theory
val certificate_theory_id: certificate -> theory_id
val eq_certificate: certificate * certificate -> bool
val join_certificate: certificate * certificate -> certificate
val join_certificate_theory: theory * theory -> theory
(*generic context*)
datatype generic = Theory of theory | Proof of Proof.context
val theory_tracing: bool Unsynchronized.ref
val proof_tracing: bool Unsynchronized.ref
val enabled_tracing: unit -> bool
val finish_tracing: unit ->
{contexts: (generic * Position.T) list,
active_contexts: int,
active_theories: int,
active_proofs: int,
total_contexts: int,
total_theories: int,
total_proofs: int}
val cases: (theory -> 'a) -> (Proof.context -> 'a) -> generic -> 'a
val mapping: (theory -> theory) -> (Proof.context -> Proof.context) -> generic -> generic
val mapping_result: (theory -> 'a * theory) -> (Proof.context -> 'a * Proof.context) ->
generic -> 'a * generic
val the_theory: generic -> theory
val the_proof: generic -> Proof.context
val map_theory: (theory -> theory) -> generic -> generic
val map_proof: (Proof.context -> Proof.context) -> generic -> generic
val map_theory_result: (theory -> 'a * theory) -> generic -> 'a * generic
val map_proof_result: (Proof.context -> 'a * Proof.context) -> generic -> 'a * generic
val theory_map: (generic -> generic) -> theory -> theory
val proof_map: (generic -> generic) -> Proof.context -> Proof.context
val theory_of: generic -> theory (*total*)
val proof_of: generic -> Proof.context (*total*)
(*thread data*)
val get_generic_context: unit -> generic option
val put_generic_context: generic option -> unit
val setmp_generic_context: generic option -> ('a -> 'b) -> 'a -> 'b
val the_generic_context: unit -> generic
val the_global_context: unit -> theory
val the_local_context: unit -> Proof.context
val >> : (generic -> generic) -> unit
val >>> : (generic -> 'a * generic) -> 'a
end;
signature PRIVATE_CONTEXT =
sig
include CONTEXT
structure Theory_Data:
sig
val declare: Position.T -> Any.T -> ((theory * Any.T) list -> Any.T) -> data_kind
val get: data_kind -> (Any.T -> 'a) -> theory -> 'a
val put: data_kind -> ('a -> Any.T) -> 'a -> theory -> theory
end
structure Proof_Data:
sig
val declare: (theory -> Any.T) -> data_kind
val get: data_kind -> (Any.T -> 'a) -> Proof.context -> 'a
val put: data_kind -> ('a -> Any.T) -> 'a -> Proof.context -> Proof.context
end
end;
structure Context: PRIVATE_CONTEXT =
struct
(*** type definitions ***)
(* context data *)
(*private copy avoids potential conflict of table exceptions*)
structure Datatab = Table(type key = int val ord = int_ord);
type data_kind = int;
val data_kind = Counter.make ();
(* theory identity *)
type id = int;
local
val new_block = Counter.make ();
fun new_elem () = Bitset.make_elem (new_block (), 0);
val var = Thread_Data.var () : id Thread_Data.var;
in
fun new_id () =
let
val id =
(case Option.map Bitset.dest_elem (Thread_Data.get var) of
NONE => new_elem ()
| SOME (m, n) =>
(case try Bitset.make_elem (m, n + 1) of
NONE => new_elem ()
| SOME elem => elem));
val _ = Thread_Data.put var (SOME id);
in id end;
end;
abstype theory_id =
Thy_Id of
{id: id, (*identifier*)
ids: Bitset.T, (*cumulative identifiers -- symbolic body content*)
name: string, (*official theory name*)
stage: int} (*index for anonymous updates*)
with
fun rep_theory_id (Thy_Id args) = args;
val make_theory_id = Thy_Id;
end;
(* theory allocation state *)
type state = {stage: int} Synchronized.var;
fun make_state () : state =
Synchronized.var "Context.state" {stage = 0};
fun next_stage (state: state) =
Synchronized.change_result state (fn {stage} => (stage + 1, {stage = stage + 1}));
(* theory and proof context *)
datatype theory =
Thy_Undef
| Thy of
(*allocation state*)
state *
(*identity*)
{theory_id: theory_id,
theory_token: theory Unsynchronized.ref,
theory_token_pos: Position.T} *
(*ancestry*)
{parents: theory list, (*immediate predecessors*)
ancestors: theory list} * (*all predecessors -- canonical reverse order*)
(*data*)
Any.T Datatab.table; (*body content*)
datatype proof =
Prf_Undef
| Prf of
(*identity*)
proof Unsynchronized.ref * (*token*)
Position.T * (*token_pos*)
theory *
(*data*)
Any.T Datatab.table;
structure Proof = struct type context = proof end;
datatype generic = Theory of theory | Proof of Proof.context;
(* heap allocations *)
val theory_tracing = Unsynchronized.ref false;
val proof_tracing = Unsynchronized.ref false;
fun enabled_tracing () = ! theory_tracing orelse ! proof_tracing;
local
val m = Integer.pow 18 2;
fun cons_tokens var token =
Synchronized.change var (fn (n, tokens) =>
let val tokens' = if n mod m = 0 then filter Unsynchronized.weak_active tokens else tokens
in (n + 1, Weak.weak (SOME token) :: tokens') end);
fun finish_tokens var =
Synchronized.change_result var (fn (n, tokens) =>
let
val tokens' = filter Unsynchronized.weak_active tokens;
val results = map_filter Unsynchronized.weak_peek tokens';
in ((n, results), (n, tokens')) end);
fun make_token guard var token0 =
if ! guard then
let
val token = Unsynchronized.ref (! token0);
val pos = Position.thread_data ();
fun assign res = (token := res; cons_tokens var token; res);
in (token, pos, assign) end
else (token0, Position.none, I);
val theory_tokens = Synchronized.var "theory_tokens" (0, []: theory Unsynchronized.weak_ref list);
val proof_tokens = Synchronized.var "proof_tokens" (0, []: proof Unsynchronized.weak_ref list);
val theory_token0 = Unsynchronized.ref Thy_Undef;
val proof_token0 = Unsynchronized.ref Prf_Undef;
in
fun theory_token () = make_token theory_tracing theory_tokens theory_token0;
fun proof_token () = make_token proof_tracing proof_tokens proof_token0;
fun finish_tracing () =
let
val _ = ML_Heap.full_gc ();
val (total_theories, token_theories) = finish_tokens theory_tokens;
val (total_proofs, token_proofs) = finish_tokens proof_tokens;
fun cons1 (thy as Thy (_, {theory_token_pos, ...}, _, _)) = cons (Theory thy, theory_token_pos)
| cons1 _ = I;
fun cons2 (ctxt as Prf (_, proof_token_pos, _, _)) = cons (Proof ctxt, proof_token_pos)
| cons2 _ = I;
val contexts = build (fold cons1 token_theories #> fold cons2 token_proofs);
val active_theories = fold (fn (Theory _, _) => Integer.add 1 | _ => I) contexts 0;
val active_proofs = fold (fn (Proof _, _) => Integer.add 1 | _ => I) contexts 0;
in
{contexts = contexts,
active_contexts = active_theories + active_proofs,
active_theories = active_theories,
active_proofs = active_proofs,
total_contexts = total_theories + total_proofs,
total_theories = total_theories,
total_proofs = total_proofs}
end;
end;
(*** theory operations ***)
fun rep_theory (Thy args) = args;
exception THEORY of string * theory list;
val state_of = #1 o rep_theory;
val theory_identity = #2 o rep_theory;
val theory_id = #theory_id o theory_identity;
val identity_of = rep_theory_id o theory_id;
val ancestry_of = #3 o rep_theory;
val data_of = #4 o rep_theory;
fun make_ancestry parents ancestors = {parents = parents, ancestors = ancestors};
fun stage_final stage = stage = 0;
val theory_id_stage = #stage o rep_theory_id;
val theory_id_final = stage_final o theory_id_stage;
val theory_id_ord = int_ord o apply2 (#id o rep_theory_id);
fun theory_id_name {long} thy_id =
let val name = #name (rep_theory_id thy_id)
in if long then name else Long_Name.base_name name end;
val theory_long_name = #name o identity_of;
val theory_base_name = Long_Name.base_name o theory_long_name;
fun theory_name {long} = if long then theory_long_name else theory_base_name;
val theory_identifier = #id o identity_of;
val parents_of = #parents o ancestry_of;
val ancestors_of = #ancestors o ancestry_of;
(* names *)
val PureN = "Pure";
fun display_name thy_id =
let
val name = theory_id_name {long = false} thy_id;
val final = theory_id_final thy_id;
in if final then name else name ^ ":" ^ string_of_int (theory_id_stage thy_id) end;
fun display_names thy =
let
val name = display_name (theory_id thy);
val ancestor_names = map theory_long_name (ancestors_of thy);
in rev (name :: ancestor_names) end;
val pretty_thy = Pretty.str_list "{" "}" o display_names;
val _ = ML_system_pp (fn _ => fn _ => Pretty.to_ML o pretty_thy);
fun pretty_abbrev_thy thy =
let
val names = display_names thy;
val n = length names;
val abbrev = if n > 5 then "..." :: List.drop (names, n - 5) else names;
in Pretty.str_list "{" "}" abbrev end;
fun get_theory long thy name =
if theory_name long thy <> name then
(case find_first (fn thy' => theory_name long thy' = name) (ancestors_of thy) of
SOME thy' => thy'
| NONE => error ("Unknown ancestor theory " ^ quote name))
else if theory_id_final (theory_id thy) then thy
else error ("Unfinished theory " ^ quote name);
(* identity *)
fun merge_ids thys =
fold (identity_of #> (fn {id, ids, ...} => fn acc => Bitset.merge (acc, ids) |> Bitset.insert id))
thys Bitset.empty;
val eq_thy_id = op = o apply2 (#id o rep_theory_id);
val eq_thy = op = o apply2 (#id o identity_of);
val proper_subthy_id = apply2 rep_theory_id #> (fn ({id, ...}, {ids, ...}) => Bitset.member ids id);
val proper_subthy = proper_subthy_id o apply2 theory_id;
fun subthy_id p = eq_thy_id p orelse proper_subthy_id p;
val subthy = subthy_id o apply2 theory_id;
(* consistent ancestors *)
fun eq_thy_consistent (thy1, thy2) =
eq_thy (thy1, thy2) orelse
(theory_base_name thy1 = theory_base_name thy2 andalso
raise THEORY ("Duplicate theory name", [thy1, thy2]));
fun extend_ancestors thy thys =
if member eq_thy_consistent thys thy then
raise THEORY ("Duplicate theory node", thy :: thys)
else thy :: thys;
val merge_ancestors = merge eq_thy_consistent;
val eq_ancestry =
apply2 ancestry_of #>
(fn ({parents, ancestors}, {parents = parents', ancestors = ancestors'}) =>
eq_list eq_thy (parents, parents') andalso eq_list eq_thy (ancestors, ancestors'));
(** theory data **)
(* data kinds and access methods *)
val data_timing = Unsynchronized.ref false;
local
type kind =
{pos: Position.T,
empty: Any.T,
merge: (theory * Any.T) list -> Any.T};
val kinds = Synchronized.var "Theory_Data" (Datatab.empty: kind Datatab.table);
fun the_kind k =
(case Datatab.lookup (Synchronized.value kinds) k of
SOME kind => kind
| NONE => raise Fail "Invalid theory data identifier");
in
fun data_kinds () =
Datatab.fold_rev (fn (k, {pos, ...}) => cons (k, pos)) (Synchronized.value kinds) [];
val invoke_pos = #pos o the_kind;
val invoke_empty = #empty o the_kind;
fun invoke_merge kind args =
if ! data_timing then
Timing.cond_timeit true ("Theory_Data.merge" ^ Position.here (#pos kind))
(fn () => #merge kind args)
else #merge kind args;
fun declare_data pos empty merge =
let
val k = data_kind ();
val kind = {pos = pos, empty = empty, merge = merge};
val _ = Synchronized.change kinds (Datatab.update (k, kind));
in k end;
fun lookup_data k thy = Datatab.lookup (data_of thy) k;
fun get_data k thy =
(case lookup_data k thy of
SOME x => x
| NONE => invoke_empty k);
fun merge_data [] = Datatab.empty
| merge_data [thy] = data_of thy
| merge_data thys =
let
fun merge (k, kind) data =
(case map_filter (fn thy => lookup_data k thy |> Option.map (pair thy)) thys of
[] => data
| [(_, x)] => Datatab.default (k, x) data
| args => Datatab.update (k, invoke_merge kind args) data);
in Datatab.fold merge (Synchronized.value kinds) (data_of (hd thys)) end;
end;
(** build theories **)
(* create theory *)
fun create_thy state ids name stage ancestry data =
let
val theory_id = make_theory_id {id = new_id (), ids = ids, name = name, stage = stage};
val (token, pos, assign) = theory_token ();
val identity = {theory_id = theory_id, theory_token = token, theory_token_pos = pos};
in assign (Thy (state, identity, ancestry, data)) end;
(* primitives *)
val pre_pure_thy =
let
val state = make_state ();
val stage = next_stage state;
in create_thy state Bitset.empty PureN stage (make_ancestry [] []) Datatab.empty end;
local
fun change_thy finish f thy =
let
val {name, stage, ...} = identity_of thy;
val Thy (state, _, ancestry, data) = thy;
val ancestry' =
if stage_final stage
then make_ancestry [thy] (extend_ancestors thy (ancestors_of thy))
else ancestry;
val ids' = merge_ids [thy];
val stage' = if finish then 0 else next_stage state;
val data' = f data;
in create_thy state ids' name stage' ancestry' data' end;
in
val update_thy = change_thy false;
val finish_thy = change_thy true I;
end;
(* join: unfinished theory nodes *)
fun join_thys [] = raise List.Empty
| join_thys thys =
let
val thy0 = hd thys;
val name0 = theory_long_name thy0;
val state0 = state_of thy0;
fun ok thy =
not (theory_id_final (theory_id thy)) andalso
theory_long_name thy = name0 andalso
eq_ancestry (thy0, thy);
val _ =
(case filter_out ok thys of
[] => ()
| bad => raise THEORY ("Cannot join theories", bad));
val stage = next_stage state0;
val ids = merge_ids thys;
val data = merge_data thys;
in create_thy state0 ids name0 stage (ancestry_of thy0) data end;
(* merge: finished theory nodes *)
fun make_parents thys =
let val thys' = distinct eq_thy thys
in thys' |> filter_out (fn thy => exists (fn thy' => proper_subthy (thy, thy')) thys') end;
fun begin_thy name imports =
if name = "" then error ("Bad theory name: " ^ quote name)
else if null imports then error "Missing theory imports"
else
let
val parents = make_parents imports;
val ancestors =
Library.foldl1 merge_ancestors (map ancestors_of parents)
|> fold extend_ancestors parents;
val ancestry = make_ancestry parents ancestors;
val state = make_state ();
val stage = next_stage state;
val ids = merge_ids parents;
val data = merge_data parents;
in create_thy state ids name stage ancestry data |> tap finish_thy end;
(* theory data *)
structure Theory_Data =
struct
val declare = declare_data;
fun get k dest thy = dest (get_data k thy);
fun put k make x = update_thy (Datatab.update (k, make x));
fun sizeof1 k thy =
Datatab.lookup (data_of thy) k |> Option.map ML_Heap.sizeof1;
end;
fun theory_data_sizeof1 thy =
build (data_of thy |> Datatab.fold_rev (fn (k, _) =>
(case Theory_Data.sizeof1 k thy of
NONE => I
| SOME n => (cons (invoke_pos k, n)))));
(*** proof context ***)
(* proof data kinds *)
local
val kinds = Synchronized.var "Proof_Data" (Datatab.empty: (theory -> Any.T) Datatab.table);
fun init_data thy =
Synchronized.value kinds |> Datatab.map (fn _ => fn init => init thy);
fun init_new_data thy =
Synchronized.value kinds |> Datatab.fold (fn (k, init) => fn data =>
if Datatab.defined data k then data
else Datatab.update (k, init thy) data);
fun init_fallback k thy =
(case Datatab.lookup (Synchronized.value kinds) k of
SOME init => init thy
| NONE => raise Fail "Invalid proof data identifier");
in
fun raw_transfer thy' (ctxt as Prf (_, _, thy, data)) =
if eq_thy (thy, thy') then ctxt
else if proper_subthy (thy, thy') then
let
val (token', pos', assign) = proof_token ();
val data' = init_new_data thy' data;
in assign (Prf (token', pos', thy', data')) end
else error "Cannot transfer proof context: not a super theory";
structure Proof_Context =
struct
fun theory_of (Prf (_, _, thy, _)) = thy;
fun init_global thy =
let val (token, pos, assign) = proof_token ()
in assign (Prf (token, pos, thy, init_data thy)) end;
fun get_global long thy name = init_global (get_theory long thy name);
end;
structure Proof_Data =
struct
fun declare init =
let
val k = data_kind ();
val _ = Synchronized.change kinds (Datatab.update (k, init));
in k end;
fun get k dest (Prf (_, _, thy, data)) =
(case Datatab.lookup data k of
SOME x => x
| NONE => init_fallback k thy) |> dest;
fun put k make x (Prf (_, _, thy, data)) =
let
val (token', pos', assign) = proof_token ();
val data' = Datatab.update (k, make x) data;
in assign (Prf (token', pos', thy, data')) end;
end;
end;
(*** theory certificate ***)
datatype certificate = Certificate of theory | Certificate_Id of theory_id;
fun certificate_theory (Certificate thy) = thy
| certificate_theory (Certificate_Id thy_id) =
error ("No content for theory certificate " ^ display_name thy_id);
fun certificate_theory_id (Certificate thy) = theory_id thy
| certificate_theory_id (Certificate_Id thy_id) = thy_id;
fun eq_certificate (Certificate thy1, Certificate thy2) = eq_thy (thy1, thy2)
| eq_certificate (Certificate_Id thy_id1, Certificate_Id thy_id2) = eq_thy_id (thy_id1, thy_id2)
| eq_certificate _ = false;
fun err_join (thy_id1, thy_id2) =
error ("Cannot join unrelated theory certificates " ^
display_name thy_id1 ^ " and " ^ display_name thy_id2);
fun join_certificate (cert1, cert2) =
let val (thy_id1, thy_id2) = apply2 certificate_theory_id (cert1, cert2) in
if eq_thy_id (thy_id1, thy_id2) then (case cert1 of Certificate _ => cert1 | _ => cert2)
else if proper_subthy_id (thy_id2, thy_id1) then cert1
else if proper_subthy_id (thy_id1, thy_id2) then cert2
else err_join (thy_id1, thy_id2)
end;
fun join_certificate_theory (thy1, thy2) =
let val (thy_id1, thy_id2) = apply2 theory_id (thy1, thy2) in
if subthy_id (thy_id2, thy_id1) then thy1
else if proper_subthy_id (thy_id1, thy_id2) then thy2
else err_join (thy_id1, thy_id2)
end;
(*** generic context ***)
fun cases f _ (Theory thy) = f thy
| cases _ g (Proof prf) = g prf;
fun mapping f g = cases (Theory o f) (Proof o g);
fun mapping_result f g = cases (apsnd Theory o f) (apsnd Proof o g);
val the_theory = cases I (fn _ => error "Ill-typed context: theory expected");
val the_proof = cases (fn _ => error "Ill-typed context: proof expected") I;
fun map_theory f = Theory o f o the_theory;
fun map_proof f = Proof o f o the_proof;
fun map_theory_result f = apsnd Theory o f o the_theory;
fun map_proof_result f = apsnd Proof o f o the_proof;
fun theory_map f = the_theory o f o Theory;
fun proof_map f = the_proof o f o Proof;
val theory_of = cases I Proof_Context.theory_of;
val proof_of = cases Proof_Context.init_global I;
(** thread data **)
local val generic_context_var = Thread_Data.var () : generic Thread_Data.var in
fun get_generic_context () = Thread_Data.get generic_context_var;
val put_generic_context = Thread_Data.put generic_context_var;
fun setmp_generic_context opt_context = Thread_Data.setmp generic_context_var opt_context;
fun the_generic_context () =
(case get_generic_context () of
SOME context => context
| _ => error "Unknown context");
val the_global_context = theory_of o the_generic_context;
val the_local_context = proof_of o the_generic_context;
end;
fun >>> f =
let
val (res, context') = f (the_generic_context ());
val _ = put_generic_context (SOME context');
in res end;
nonfix >>;
fun >> f = >>> (fn context => ((), f context));
val _ = put_generic_context (SOME (Theory pre_pure_thy));
end;
structure Basic_Context: BASIC_CONTEXT = Context;
open Basic_Context;
(*** type-safe interfaces for data declarations ***)
(** theory data **)
signature THEORY_DATA'_ARGS =
sig
type T
val empty: T
val merge: (theory * T) list -> T
end;
signature THEORY_DATA_ARGS =
sig
type T
val empty: T
val merge: T * T -> T
end;
signature THEORY_DATA =
sig
type T
val get: theory -> T
val put: T -> theory -> theory
val map: (T -> T) -> theory -> theory
end;
functor Theory_Data'(Data: THEORY_DATA'_ARGS): THEORY_DATA =
struct
type T = Data.T;
exception Data of T;
val kind =
let val pos = Position.thread_data () in
Context.Theory_Data.declare
pos
(Data Data.empty)
(Data o Data.merge o map (fn (thy, Data x) => (thy, x)))
end;
val get = Context.Theory_Data.get kind (fn Data x => x);
val put = Context.Theory_Data.put kind Data;
fun map f thy = put (f (get thy)) thy;
end;
functor Theory_Data(Data: THEORY_DATA_ARGS): THEORY_DATA =
Theory_Data'
(
type T = Data.T;
val empty = Data.empty;
fun merge args = Library.foldl (fn (a, (_, b)) => Data.merge (a, b)) (#2 (hd args), tl args)
);
(** proof data **)
signature PROOF_DATA_ARGS =
sig
type T
val init: theory -> T
end;
signature PROOF_DATA =
sig
type T
val get: Proof.context -> T
val put: T -> Proof.context -> Proof.context
val map: (T -> T) -> Proof.context -> Proof.context
end;
functor Proof_Data(Data: PROOF_DATA_ARGS): PROOF_DATA =
struct
type T = Data.T;
exception Data of T;
val kind = Context.Proof_Data.declare (Data o Data.init);
val get = Context.Proof_Data.get kind (fn Data x => x);
val put = Context.Proof_Data.put kind Data;
fun map f prf = put (f (get prf)) prf;
end;
(** generic data **)
signature GENERIC_DATA_ARGS =
sig
type T
val empty: T
val merge: T * T -> T
end;
signature GENERIC_DATA =
sig
type T
val get: Context.generic -> T
val put: T -> Context.generic -> Context.generic
val map: (T -> T) -> Context.generic -> Context.generic
end;
functor Generic_Data(Data: GENERIC_DATA_ARGS): GENERIC_DATA =
struct
structure Thy_Data = Theory_Data(Data);
structure Prf_Data = Proof_Data(type T = Data.T val init = Thy_Data.get);
type T = Data.T;
fun get (Context.Theory thy) = Thy_Data.get thy
| get (Context.Proof prf) = Prf_Data.get prf;
fun put x (Context.Theory thy) = Context.Theory (Thy_Data.put x thy)
| put x (Context.Proof prf) = Context.Proof (Prf_Data.put x prf);
fun map f ctxt = put (f (get ctxt)) ctxt;
end;
(*hide private interface*)
structure Context: CONTEXT = Context;