1 (* Title: Pure/axclass.ML
2 Author: Markus Wenzel, TU Muenchen
4 Type classes defined as predicates, associated with a record of
10 val define_class: binding * class list -> string list ->
11 (Thm.binding * term list) list -> theory -> class * theory
12 val add_classrel: thm -> theory -> theory
13 val add_arity: thm -> theory -> theory
14 val prove_classrel: class * class -> tactic -> theory -> theory
15 val prove_arity: string * sort list * sort -> tactic -> theory -> theory
16 val get_info: theory -> class ->
17 {def: thm, intro: thm, axioms: thm list, params: (string * typ) list}
18 val class_intros: theory -> thm list
19 val class_of_param: theory -> string -> class option
20 val cert_classrel: theory -> class * class -> class * class
21 val read_classrel: theory -> xstring * xstring -> class * class
22 val axiomatize_class: binding * class list -> theory -> theory
23 val axiomatize_class_cmd: binding * xstring list -> theory -> theory
24 val axiomatize_classrel: (class * class) list -> theory -> theory
25 val axiomatize_classrel_cmd: (xstring * xstring) list -> theory -> theory
26 val axiomatize_arity: arity -> theory -> theory
27 val axiomatize_arity_cmd: xstring * string list * string -> theory -> theory
28 val instance_name: string * class -> string
29 val declare_overloaded: string * typ -> theory -> term * theory
30 val define_overloaded: binding -> string * term -> theory -> thm * theory
31 val unoverload: theory -> thm -> thm
32 val overload: theory -> thm -> thm
33 val unoverload_conv: theory -> conv
34 val overload_conv: theory -> conv
35 val unoverload_const: theory -> string * typ -> string
36 val lookup_inst_param: Consts.T -> ((string * string) * 'a) list -> string * typ -> 'a option
37 val param_of_inst: theory -> string * string -> string
38 val inst_of_param: theory -> string -> (string * string) option
39 val arity_property: theory -> class * string -> string -> string list
41 val of_sort: theory -> typ * sort -> cache -> thm list * cache (*exception Sorts.CLASS_ERROR*)
47 structure AxClass: AX_CLASS =
52 (* class parameters (canonical order) *)
54 type param = string * class;
56 fun add_param pp ((x, c): param) params =
57 (case AList.lookup (op =) params x of
58 NONE => (x, c) :: params
59 | SOME c' => error ("Duplicate class parameter " ^ quote x ^
60 " for " ^ Pretty.string_of_sort pp [c] ^
61 (if c = c' then "" else " and " ^ Pretty.string_of_sort pp [c'])));
63 fun merge_params _ ([], qs) = qs
64 | merge_params pp (ps, qs) =
65 fold_rev (fn q => if member (op =) ps q then I else add_param pp q) qs ps;
72 val axiomsN = "axioms";
74 datatype axclass = AxClass of
78 params: (string * typ) list};
80 type axclasses = axclass Symtab.table * param list;
82 fun make_axclass ((def, intro, axioms), params) = AxClass
83 {def = def, intro = intro, axioms = axioms, params = params};
85 fun merge_axclasses pp ((tab1, params1), (tab2, params2)) : axclasses =
86 (Symtab.merge (K true) (tab1, tab2), merge_params pp (params1, params2));
91 val classrel_prefix = "classrel_";
92 val arity_prefix = "arity_";
95 ((class * class) * thm) list *
96 ((class * sort list) * thm) list Symtab.table;
98 fun merge_instances ((classrel1, arities1): instances, (classrel2, arities2)) =
99 (merge (eq_fst op =) (classrel1, classrel2),
100 Symtab.join (K (merge (eq_fst op =))) (arities1, arities2));
103 (* instance parameters *)
106 (string * thm) Symtab.table Symtab.table
107 (*constant name ~> type constructor ~> (constant name, equation)*)
108 * (string * string) Symtab.table; (*constant name ~> (constant name, type constructor)*)
110 fun merge_inst_params ((const_param1, param_const1), (const_param2, param_const2)) =
111 (Symtab.join (K (Symtab.merge (K true))) (const_param1, const_param2),
112 Symtab.merge (K true) (param_const1, param_const2));
117 structure AxClassData = TheoryDataFun
119 type T = axclasses * (instances * inst_params);
120 val empty = ((Symtab.empty, []), (([], Symtab.empty), (Symtab.empty, Symtab.empty)));
123 fun merge pp ((axclasses1, (instances1, inst_params1)), (axclasses2, (instances2, inst_params2))) =
124 (merge_axclasses pp (axclasses1, axclasses2),
125 (merge_instances (instances1, instances2), merge_inst_params (inst_params1, inst_params2)));
129 (* maintain axclasses *)
131 val get_axclasses = #1 o AxClassData.get;
132 val map_axclasses = AxClassData.map o apfst;
134 val lookup_def = Symtab.lookup o #1 o get_axclasses;
137 (case lookup_def thy c of
138 SOME (AxClass info) => info
139 | NONE => error ("No such axclass: " ^ quote c));
141 fun class_intros thy =
144 (case lookup_def thy c of SOME (AxClass {intro, ...}) => cons intro | _ => I);
145 val classes = Sign.all_classes thy;
146 in map (Thm.class_triv thy) classes @ fold add_intro classes [] end;
149 fun get_params thy pred =
150 let val params = #2 (get_axclasses thy);
151 in fold (fn (x, c) => if pred c then cons x else I) params [] end;
153 fun params_of thy c = get_params thy (fn c' => c' = c);
154 fun all_params_of thy S = get_params thy (fn c => Sign.subsort thy (S, [c]));
156 fun class_of_param thy = AList.lookup (op =) (#2 (get_axclasses thy));
159 (* maintain instances *)
161 fun instance_name (a, c) = Long_Name.base_name c ^ "_" ^ Long_Name.base_name a;
163 val get_instances = #1 o #2 o AxClassData.get;
164 val map_instances = AxClassData.map o apsnd o apfst;
167 fun the_classrel thy (c1, c2) =
168 (case AList.lookup (op =) (#1 (get_instances thy)) (c1, c2) of
169 SOME th => Thm.transfer thy th
170 | NONE => error ("Unproven class relation " ^
171 Syntax.string_of_classrel (ProofContext.init thy) [c1, c2]));
173 fun put_classrel arg = map_instances (fn (classrel, arities) =>
174 (insert (eq_fst op =) arg classrel, arities));
177 fun the_arity thy a (c, Ss) =
178 (case AList.lookup (op =) (Symtab.lookup_list (#2 (get_instances thy)) a) (c, Ss) of
179 SOME th => Thm.transfer thy th
180 | NONE => error ("Unproven type arity " ^
181 Syntax.string_of_arity (ProofContext.init thy) (a, Ss, [c])));
183 fun arity_property thy (c, a) x =
184 Symtab.lookup_list (snd (get_instances thy)) a
185 |> map_filter (fn ((c', _), th) => if c = c'
186 then AList.lookup (op =) (Thm.get_tags th) x else NONE)
189 fun insert_arity_completions thy (t, ((c, Ss), th)) arities =
191 val algebra = Sign.classes_of thy;
192 val super_class_completions = Sign.super_classes thy c
193 |> filter_out (fn c1 => exists (fn ((c2, Ss2), _) => c1 = c2
194 andalso Sorts.sorts_le algebra (Ss2, Ss)) (Symtab.lookup_list arities t))
195 val tags = Thm.get_tags th;
196 val completions = map (fn c1 => (Sorts.weaken algebra
197 (fn (th, c2) => fn c3 => th RS the_classrel thy (c2, c3)) (th, c) c1
198 |> Thm.map_tags (K tags) |> Thm.close_derivation, c1)) super_class_completions;
199 val arities' = fold (fn (th1, c1) => Symtab.cons_list (t, ((c1, Ss), th1)))
201 in (completions, arities') end;
203 fun put_arity ((t, Ss, c), th) thy =
205 val th' = (Thm.map_tags o AList.default (op =))
206 (Markup.theory_nameN, Context.theory_name thy) th;
207 val arity' = (t, ((c, Ss), th'));
210 |> map_instances (fn (classrel, arities) => (classrel,
212 |> Symtab.insert_list (eq_fst op =) arity'
213 |> insert_arity_completions thy arity'
217 fun complete_arities thy =
219 val arities = snd (get_instances thy);
220 val (completions, arities') = arities
221 |> fold_map (insert_arity_completions thy) (Symtab.dest_list arities)
223 in if null completions
225 else SOME (thy |> map_instances (fn (classrel, _) => (classrel, arities')))
228 val _ = Context.>> (Context.map_theory (Theory.at_begin complete_arities));
231 (* maintain instance parameters *)
233 val get_inst_params = #2 o #2 o AxClassData.get;
234 val map_inst_params = AxClassData.map o apsnd o apsnd;
236 fun get_inst_param thy (c, tyco) =
237 case Symtab.lookup ((the_default Symtab.empty o Symtab.lookup (fst (get_inst_params thy))) c) tyco
239 | NONE => error ("No instance parameter for constant " ^ quote c
240 ^ " on type constructor " ^ quote tyco);
242 fun add_inst_param (c, tyco) inst = (map_inst_params o apfst
243 o Symtab.map_default (c, Symtab.empty)) (Symtab.update_new (tyco, inst))
244 #> (map_inst_params o apsnd) (Symtab.update_new (fst inst, (c, tyco)));
246 val inst_of_param = Symtab.lookup o snd o get_inst_params;
247 val param_of_inst = fst oo get_inst_param;
249 fun inst_thms thy = (Symtab.fold (Symtab.fold (cons o snd o snd) o snd) o fst)
250 (get_inst_params thy) [];
252 fun get_inst_tyco consts = try (fst o dest_Type o the_single o Consts.typargs consts);
254 fun unoverload thy = MetaSimplifier.simplify true (inst_thms thy);
255 fun overload thy = MetaSimplifier.simplify true (map Thm.symmetric (inst_thms thy));
257 fun unoverload_conv thy = MetaSimplifier.rewrite true (inst_thms thy);
258 fun overload_conv thy = MetaSimplifier.rewrite true (map Thm.symmetric (inst_thms thy));
260 fun lookup_inst_param consts params (c, T) = case get_inst_tyco consts (c, T)
261 of SOME tyco => AList.lookup (op =) params (c, tyco)
264 fun unoverload_const thy (c_ty as (c, _)) =
265 case class_of_param thy c
266 of SOME class => (case get_inst_tyco (Sign.consts_of thy) c_ty
267 of SOME tyco => try (param_of_inst thy) (c, tyco) |> the_default c
274 (* class relations *)
276 fun cert_classrel thy raw_rel =
278 val string_of_sort = Syntax.string_of_sort_global thy;
279 val (c1, c2) = pairself (Sign.certify_class thy) raw_rel;
280 val _ = Sign.primitive_classrel (c1, c2) (Theory.copy thy);
282 (case subtract (op =) (all_params_of thy [c1]) (all_params_of thy [c2]) of
284 | xs => raise TYPE ("Class " ^ string_of_sort [c1] ^ " lacks parameter(s) " ^
285 commas_quote xs ^ " of " ^ string_of_sort [c2], [], []));
288 fun read_classrel thy raw_rel =
289 cert_classrel thy (pairself (Sign.read_class thy) raw_rel)
290 handle TYPE (msg, _, _) => error msg;
293 (* declaration and definition of instances of overloaded constants *)
295 fun inst_tyco_of thy (c, T) = case get_inst_tyco (Sign.consts_of thy) (c, T)
297 | NONE => error ("Illegal type for instantiation of class parameter: "
298 ^ quote (c ^ " :: " ^ Syntax.string_of_typ_global thy T));
300 fun declare_overloaded (c, T) thy =
302 val class = case class_of_param thy c
303 of SOME class => class
304 | NONE => error ("Not a class parameter: " ^ quote c);
305 val tyco = inst_tyco_of thy (c, T);
306 val name_inst = instance_name (tyco, class) ^ "_inst";
307 val c' = Long_Name.base_name c ^ "_" ^ Long_Name.base_name tyco;
308 val T' = Type.strip_sorts T;
311 |> Sign.mandatory_path name_inst
312 |> Sign.declare_const [] ((Binding.name c', T'), NoSyn)
313 |-> (fn const' as Const (c'', _) =>
314 Thm.add_def false true
315 (Binding.name (Thm.def_name c'), Logic.mk_equals (Const (c, T'), const'))
317 #-> (fn thm => add_inst_param (c, tyco) (c'', thm)
318 #> PureThy.add_thm ((Binding.name c', thm), [Thm.kind_internal])
320 #> Sign.restore_naming thy
321 #> pair (Const (c, T))))
324 fun define_overloaded b (c, t) thy =
326 val T = Term.fastype_of t;
327 val tyco = inst_tyco_of thy (c, T);
328 val (c', eq) = get_inst_param thy (c, tyco);
329 val prop = Logic.mk_equals (Const (c', T), t);
330 val b' = Thm.def_binding_optional
331 (Binding.name (Long_Name.base_name c ^ "_" ^ Long_Name.base_name tyco)) b;
334 |> Thm.add_def false false (b', prop)
335 |>> (fn thm => Drule.transitive_thm OF [eq, thm])
339 (* primitive rules *)
341 fun add_classrel th thy =
343 fun err () = raise THM ("add_classrel: malformed class relation", 0, [th]);
344 val prop = Thm.plain_prop_of (Thm.transfer thy th);
345 val rel = Logic.dest_classrel prop handle TERM _ => err ();
346 val (c1, c2) = cert_classrel thy rel handle TYPE _ => err ();
349 |> Sign.primitive_classrel (c1, c2)
350 |> put_classrel ((c1, c2), Thm.close_derivation (Drule.unconstrainTs th))
351 |> perhaps complete_arities
354 fun add_arity th thy =
356 fun err () = raise THM ("add_arity: malformed type arity", 0, [th]);
357 val prop = Thm.plain_prop_of (Thm.transfer thy th);
358 val (t, Ss, c) = Logic.dest_arity prop handle TERM _ => err ();
359 val T = Type (t, map TFree (Name.names Name.context Name.aT Ss));
360 val missing_params = Sign.complete_sort thy [c]
361 |> maps (these o Option.map #params o try (get_info thy))
362 |> filter_out (fn (const, _) => can (get_inst_param thy) (const, t))
363 |> (map o apsnd o map_atyps) (K T);
364 val _ = map (Sign.certify_sort thy) Ss = Ss orelse err ();
365 val th' = Drule.unconstrainTs th;
368 |> fold (snd oo declare_overloaded) missing_params
369 |> Sign.primitive_arity (t, Ss, [c])
370 |> put_arity ((t, Ss, c), th')
374 (* tactical proofs *)
376 fun prove_classrel raw_rel tac thy =
378 val ctxt = ProofContext.init thy;
379 val (c1, c2) = cert_classrel thy raw_rel;
380 val th = Goal.prove ctxt [] [] (Logic.mk_classrel (c1, c2)) (K tac) handle ERROR msg =>
381 cat_error msg ("The error(s) above occurred while trying to prove class relation " ^
382 quote (Syntax.string_of_classrel ctxt [c1, c2]));
385 |> PureThy.add_thms [((Binding.name
386 (prefix classrel_prefix (Logic.name_classrel (c1, c2))), th), [])]
387 |-> (fn [th'] => add_classrel th')
390 fun prove_arity raw_arity tac thy =
392 val ctxt = ProofContext.init thy;
393 val arity = Sign.cert_arity thy raw_arity;
394 val names = map (prefix arity_prefix) (Logic.name_arities arity);
395 val props = Logic.mk_arities arity;
396 val ths = Goal.prove_multi ctxt [] [] props
397 (fn _ => Goal.precise_conjunction_tac (length props) 1 THEN tac) handle ERROR msg =>
398 cat_error msg ("The error(s) above occurred while trying to prove type arity " ^
399 quote (Syntax.string_of_arity ctxt arity));
402 |> PureThy.add_thms (map (rpair []) (map Binding.name names ~~ ths))
408 (** class definitions **)
410 fun split_defined n eq =
413 (eq RS Drule.equal_elim_rule2)
414 |> Conjunction.curry_balanced n
415 |> n = 0 ? Thm.eq_assumption 1;
419 (eq RS Drule.equal_elim_rule1)
420 |> BalancedTree.dest (fn th =>
421 (th RS Conjunction.conjunctionD1, th RS Conjunction.conjunctionD2)) n;
422 in (intro, dests) end;
424 fun define_class (bclass, raw_super) raw_params raw_specs thy =
426 val ctxt = ProofContext.init thy;
427 val pp = Syntax.pp ctxt;
432 val bconst = Binding.map_name Logic.const_of_class bclass;
433 val class = Sign.full_name thy bclass;
434 val super = Sign.minimize_sort thy (Sign.certify_sort thy raw_super);
436 fun check_constraint (a, S) =
437 if Sign.subsort thy (super, S) then ()
438 else error ("Sort constraint of type variable " ^
439 setmp show_sorts true (Pretty.string_of_typ pp) (TFree (a, S)) ^
440 " needs to be weaker than " ^ Pretty.string_of_sort pp super);
445 val params = raw_params |> map (fn p =>
447 val T = Sign.the_const_type thy p;
449 (case Term.add_tvarsT T [] of
450 [((a, _), S)] => check_constraint (a, S)
451 | _ => error ("Exactly one type variable expected in class parameter " ^ quote p));
452 val T' = Term.map_type_tvar (fn _ => TFree (Name.aT, [class])) T;
459 (case Term.add_tfrees t [] of
460 [(a, S)] => check_constraint (a, S)
462 | _ => error ("Multiple type variables in class axiom:\n" ^ Pretty.string_of_term pp t);
464 |> Term.map_types (Term.map_atyps (fn TFree _ => Term.aT [] | U => U))
465 |> Logic.close_form);
467 val axiomss = map (map (prep_axiom o Sign.cert_prop thy) o snd) raw_specs;
468 val name_atts = map fst raw_specs;
473 val conjs = map (curry Logic.mk_of_class (Term.aT [])) super @ flat axiomss;
475 Logic.mk_equals (Logic.mk_of_class (Term.aT [], class), Logic.mk_conjunction_balanced conjs);
477 val ([def], def_thy) =
479 |> Sign.primitive_class (bclass, super)
480 |> PureThy.add_defs false [((Binding.map_name Thm.def_name bconst, class_eq), [])];
481 val (raw_intro, (raw_classrel, raw_axioms)) =
482 split_defined (length conjs) def ||> chop (length super);
487 val class_triv = Thm.class_triv def_thy class;
488 val ([(_, [intro]), (_, classrel), (_, axioms)], facts_thy) =
490 |> Sign.mandatory_path (Binding.name_of bconst)
491 |> PureThy.note_thmss ""
492 [((Binding.name introN, []), [([Drule.standard raw_intro], [])]),
493 ((Binding.name superN, []), [(map Drule.standard raw_classrel, [])]),
494 ((Binding.name axiomsN, []),
495 [(map (fn th => Drule.standard (class_triv RS th)) raw_axioms, [])])]
496 ||> Sign.restore_naming def_thy;
501 val axclass = make_axclass ((def, intro, axioms), params);
504 |> fold put_classrel (map (pair class) super ~~ classrel)
505 |> Sign.add_path (Binding.name_of bconst)
506 |> PureThy.note_thmss "" (name_atts ~~ map Thm.simple_fact (unflat axiomss axioms)) |> snd
507 |> Sign.restore_naming facts_thy
508 |> map_axclasses (fn (axclasses, parameters) =>
509 (Symtab.update (class, axclass) axclasses,
510 fold (fn (x, _) => add_param pp (x, class)) params parameters));
512 in (class, result_thy) end;
516 (** axiomatizations **)
520 fun axiomatize prep mk name add raw_args thy =
522 val args = prep thy raw_args;
524 val names = name args;
527 |> PureThy.add_axioms (map (rpair []) (map Binding.name names ~~ specs))
531 fun ax_classrel prep =
532 axiomatize (map o prep) (map Logic.mk_classrel)
533 (map (prefix classrel_prefix o Logic.name_classrel)) add_classrel;
536 axiomatize prep Logic.mk_arities
537 (map (prefix arity_prefix) o Logic.name_arities) add_arity;
540 (Logic.const_of_class c, Term.itselfT (Term.aT []) --> propT);
542 fun ax_class prep_class prep_classrel (bclass, raw_super) thy =
544 val class = Sign.full_name thy bclass;
545 val super = map (prep_class thy) raw_super |> Sign.minimize_sort thy;
548 |> Sign.primitive_class (bclass, super)
549 |> ax_classrel prep_classrel (map (fn c => (class, c)) super)
550 |> Theory.add_deps "" (class_const class) (map class_const super)
555 val axiomatize_class = ax_class Sign.certify_class cert_classrel;
556 val axiomatize_class_cmd = ax_class Sign.read_class read_classrel;
557 val axiomatize_classrel = ax_classrel cert_classrel;
558 val axiomatize_classrel_cmd = ax_classrel read_classrel;
559 val axiomatize_arity = ax_arity Sign.cert_arity;
560 val axiomatize_arity_cmd = ax_arity Sign.read_arity;
566 (** explicit derivations -- cached **)
568 datatype cache = Types of (class * thm) list Typtab.table;
572 fun lookup_type (Types cache) = AList.lookup (op =) o Typtab.lookup_list cache;
573 fun insert_type T der (Types cache) = Types (Typtab.insert_list (eq_fst op =) (T, der) cache);
575 fun derive_type _ (_, []) = []
576 | derive_type thy (typ, sort) =
578 val certT = Thm.ctyp_of thy;
579 val vars = Term.fold_atyps
580 (fn T as TFree (_, S) => insert (eq_fst op =) (T, S)
581 | T as TVar (_, S) => insert (eq_fst op =) (T, S)
584 |> map (fn (T, S) => (T, Thm.of_sort (certT T, S) ~~ S));
585 val ths = (typ, sort)
586 |> Sorts.of_sort_derivation (Syntax.pp_global thy) (Sign.classes_of thy)
588 fn (th, c1) => fn c2 => th RS the_classrel thy (c1, c2),
590 fn a => fn dom => fn c =>
591 let val Ss = map (map snd) dom and ths = maps (map fst) dom
592 in ths MRS the_arity thy a (c, Ss) end,
594 the_default [] o AList.lookup (op =) hyps};
599 fun of_sort thy (typ, sort) cache =
601 val sort' = filter (is_none o lookup_type cache typ) sort;
602 val ths' = derive_type thy (typ, sort')
603 handle ERROR msg => cat_error msg ("The error(s) above occurred for sort derivation: " ^
604 Syntax.string_of_typ_global thy typ ^ " :: " ^ Syntax.string_of_sort_global thy sort');
605 val cache' = cache |> fold (insert_type typ) (sort' ~~ ths');
608 Goal.finish (the (lookup_type cache' typ c) RS
609 Goal.init (Thm.cterm_of thy (Logic.mk_of_class (typ, c))))
610 |> Thm.adjust_maxidx_thm ~1);
611 in (ths, cache') end;
615 val cache = Types Typtab.empty;