src/Pure/theory.ML
author wenzelm
Wed Jul 13 16:07:24 2005 +0200 (2005-07-13)
changeset 16803 014090d1e64b
parent 16743 21dbff595bf6
child 16883 a89fafe1cbd8
permissions -rw-r--r--
tuned;
     1 (*  Title:      Pure/theory.ML
     2     ID:         $Id$
     3     Author:     Lawrence C Paulson and Markus Wenzel
     4 
     5 Logical theory content: axioms, definitions, oracles.
     6 *)
     7 
     8 signature BASIC_THEORY =
     9 sig
    10   type theory
    11   type theory_ref
    12   val sign_of: theory -> theory    (*obsolete*)
    13   val rep_theory: theory ->
    14    {axioms: term NameSpace.table,
    15     defs: Defs.graph,
    16     oracles: ((theory * Object.T -> term) * stamp) NameSpace.table}
    17   val parents_of: theory -> theory list
    18   val ancestors_of: theory -> theory list
    19   val eq_thy: theory * theory -> bool
    20   val subthy: theory * theory -> bool
    21   val cert_axm: theory -> string * term -> string * term
    22   val read_def_axm: theory * (indexname -> typ option) * (indexname -> sort option) ->
    23     string list -> string * string -> string * term
    24   val read_axm: theory -> string * string -> string * term
    25   val inferT_axm: theory -> string * term -> string * term
    26 end
    27 
    28 signature THEORY =
    29 sig
    30   include BASIC_THEORY
    31   include SIGN_THEORY
    32   val begin_theory: string -> theory list -> theory
    33   val end_theory: theory -> theory
    34   val checkpoint: theory -> theory
    35   val copy: theory -> theory
    36   val init_data: theory -> theory
    37   val axiom_space: theory -> NameSpace.T
    38   val oracle_space: theory -> NameSpace.T
    39   val axioms_of: theory -> (string * term) list
    40   val all_axioms_of: theory -> (string * term) list
    41   val defs_of : theory -> Defs.graph
    42   val self_ref: theory -> theory_ref
    43   val deref: theory_ref -> theory
    44   val merge: theory * theory -> theory                     (*exception TERM*)
    45   val merge_refs: theory_ref * theory_ref -> theory_ref    (*exception TERM*)
    46   val requires: theory -> string -> string -> unit
    47   val assert_super: theory -> theory -> theory
    48   val add_axioms: (bstring * string) list -> theory -> theory
    49   val add_axioms_i: (bstring * term) list -> theory -> theory
    50   val add_defs: bool -> (bstring * string) list -> theory -> theory
    51   val add_defs_i: bool -> (bstring * term) list -> theory -> theory
    52   val add_finals: bool -> string list -> theory -> theory
    53   val add_finals_i: bool -> term list -> theory -> theory
    54   val add_oracle: bstring * (theory * Object.T -> term) -> theory -> theory
    55 end
    56 
    57 structure Theory: THEORY =
    58 struct
    59 
    60 (** type theory **)
    61 
    62 (* context operations *)
    63 
    64 type theory = Context.theory;
    65 type theory_ref = Context.theory_ref;
    66 
    67 val eq_thy = Context.eq_thy;
    68 val subthy = Context.subthy;
    69 
    70 val parents_of = Context.parents_of;
    71 val ancestors_of = Context.ancestors_of;
    72 
    73 val self_ref = Context.self_ref;
    74 val deref = Context.deref;
    75 val merge = Context.merge;
    76 val merge_refs = Context.merge_refs;
    77 
    78 val begin_theory = Sign.local_path oo Context.begin_thy Sign.pp;
    79 val end_theory = Context.finish_thy;
    80 val checkpoint = Context.checkpoint_thy;
    81 val copy = Context.copy_thy;
    82 
    83 
    84 (* signature operations *)
    85 
    86 val sign_of = I;
    87 
    88 structure SignTheory: SIGN_THEORY = Sign;
    89 open SignTheory;
    90 
    91 
    92 
    93 (** diagnostics **)  (* FIXME belongs to defs.ML *)
    94 
    95 fun pretty_const pp (c, T) =
    96  [Pretty.str c, Pretty.str " ::", Pretty.brk 1,
    97   Pretty.quote (Pretty.typ pp (Type.freeze_type T))];    (* FIXME zero indexes!? *)
    98 
    99 fun pretty_path pp path = fold_rev (fn (T, c, def) =>
   100   fn [] => [Pretty.block (pretty_const pp (c, T))]
   101    | prts => Pretty.block (pretty_const pp (c, T) @
   102       [Pretty.brk 1, Pretty.str ("depends via " ^ quote def ^ " on")]) :: prts) path [];
   103 
   104 fun chain_history_msg s =    (* FIXME huh!? *)
   105   if Defs.chain_history () then s ^ ": "
   106   else s ^ " (set DEFS_CHAIN_HISTORY=ON for full history): ";
   107 
   108 fun defs_circular pp path =
   109   Pretty.str (chain_history_msg "Cyclic dependency of definitions") :: pretty_path pp path
   110   |> Pretty.chunks |> Pretty.string_of;
   111 
   112 fun defs_infinite_chain pp path =
   113   Pretty.str (chain_history_msg "Infinite chain of definitions") :: pretty_path pp path
   114   |> Pretty.chunks |> Pretty.string_of;
   115 
   116 fun defs_clash def1 def2 = "Type clash in definitions " ^ quote def1 ^ " and " ^ quote def2;
   117 
   118 fun defs_final pp const =
   119   (Pretty.str "Attempt to define final constant" :: Pretty.brk 1 :: pretty_const pp const)
   120   |> Pretty.block |> Pretty.string_of;
   121 
   122 
   123 
   124 (** datatype thy **)
   125 
   126 datatype thy = Thy of
   127  {axioms: term NameSpace.table,
   128   defs: Defs.graph,
   129   oracles: ((theory * Object.T -> term) * stamp) NameSpace.table};
   130 
   131 fun make_thy (axioms, defs, oracles) =
   132   Thy {axioms = axioms, defs = defs, oracles = oracles};
   133 
   134 fun err_dup_axms dups = error ("Duplicate axiom(s): " ^ commas_quote dups);
   135 fun err_dup_oras dups = error ("Duplicate oracle(s): " ^ commas_quote dups);
   136 
   137 structure ThyData = TheoryDataFun
   138 (struct
   139   val name = "Pure/theory";
   140   type T = thy;
   141   val empty = make_thy (NameSpace.empty_table, Defs.empty, NameSpace.empty_table);
   142   val copy = I;
   143 
   144   fun extend (Thy {axioms, defs, oracles}) = make_thy (NameSpace.empty_table, defs, oracles);
   145 
   146   fun merge pp (thy1, thy2) =
   147     let
   148       val Thy {axioms = _, defs = defs1, oracles = oracles1} = thy1;
   149       val Thy {axioms = _, defs = defs2, oracles = oracles2} = thy2;
   150 
   151       val axioms = NameSpace.empty_table;
   152       val defs = Defs.merge defs1 defs2  (* FIXME produce errors in defs.ML *)
   153         handle Defs.CIRCULAR namess => error (defs_circular pp namess)
   154           | Defs.INFINITE_CHAIN namess => error (defs_infinite_chain pp namess);
   155       val oracles = NameSpace.merge_tables eq_snd (oracles1, oracles2)
   156         handle Symtab.DUPS dups => err_dup_oras dups;
   157     in make_thy (axioms, defs, oracles) end;
   158 
   159   fun print _ _ = ();
   160 end);
   161 
   162 val init_data = ThyData.init;
   163 
   164 fun rep_theory thy = ThyData.get thy |> (fn Thy args => args);
   165 
   166 fun map_thy f = ThyData.map (fn (Thy {axioms, defs, oracles}) =>
   167   make_thy (f (axioms, defs, oracles)));
   168 
   169 fun map_axioms f = map_thy (fn (axioms, defs, oracles) => (f axioms, defs, oracles));
   170 fun map_defs f = map_thy (fn (axioms, defs, oracles) => (axioms, f defs, oracles));
   171 fun map_oracles f = map_thy (fn (axioms, defs, oracles) => (axioms, defs, f oracles));
   172 
   173 
   174 (* basic operations *)
   175 
   176 val axiom_space = #1 o #axioms o rep_theory;
   177 val oracle_space = #1 o #oracles o rep_theory;
   178 
   179 val axioms_of = Symtab.dest o #2 o #axioms o rep_theory;
   180 fun all_axioms_of thy = List.concat (map axioms_of (thy :: ancestors_of thy));
   181 
   182 val defs_of = #defs o rep_theory;
   183 
   184 fun requires thy name what =
   185   if Context.exists_name name thy then ()
   186   else error ("Require theory " ^ quote name ^ " as an ancestor for " ^ what);
   187 
   188 fun assert_super thy1 thy2 =
   189   if subthy (thy1, thy2) then thy2
   190   else raise THEORY ("Not a super theory", [thy1, thy2]);
   191 
   192 
   193 
   194 (** add axioms **)
   195 
   196 (* prepare axioms *)
   197 
   198 fun err_in_axm name =
   199   error ("The error(s) above occurred in axiom " ^ quote name);
   200 
   201 fun no_vars pp tm =
   202   (case (Term.term_vars tm, Term.term_tvars tm) of
   203     ([], []) => tm
   204   | (ts, ixns) => error (Pretty.string_of (Pretty.block (Pretty.breaks
   205       (Pretty.str "Illegal schematic variable(s) in term:" ::
   206        map (Pretty.term pp) ts @ map (Pretty.typ pp o TVar) ixns)))));
   207 
   208 fun cert_axm thy (name, raw_tm) =
   209   let
   210     val pp = Sign.pp thy;
   211     val (t, T, _) = Sign.certify_term pp thy raw_tm
   212       handle TYPE (msg, _, _) => error msg
   213         | TERM (msg, _) => error msg;
   214   in
   215     Term.no_dummy_patterns t handle TERM (msg, _) => error msg;
   216     assert (T = propT) "Term not of type prop";
   217     (name, no_vars pp t)
   218   end;
   219 
   220 fun read_def_axm (thy, types, sorts) used (name, str) =
   221   let
   222     val ts = Syntax.read thy (Sign.is_logtype thy) (Sign.syn_of thy) propT str;
   223     val (t, _) = Sign.infer_types (Sign.pp thy) thy types sorts used true (ts, propT);
   224   in cert_axm thy (name, t) end
   225   handle ERROR => err_in_axm name;
   226 
   227 fun read_axm thy name_str = read_def_axm (thy, K NONE, K NONE) [] name_str;
   228 
   229 fun inferT_axm thy (name, pre_tm) =
   230   let
   231     val pp = Sign.pp thy;
   232     val (t, _) = Sign.infer_types pp thy (K NONE) (K NONE) [] true ([pre_tm], propT);
   233   in (name, no_vars pp t) end
   234   handle ERROR => err_in_axm name;
   235 
   236 
   237 (* add_axioms(_i) *)
   238 
   239 local
   240 
   241 fun gen_add_axioms prep_axm raw_axms thy = thy |> map_axioms (fn axioms =>
   242   let
   243     val axms = map (apsnd (Term.compress_term o Logic.varify) o prep_axm thy) raw_axms;
   244     val axioms' = NameSpace.extend_table (Sign.naming_of thy) (axioms, axms)
   245       handle Symtab.DUPS dups => err_dup_axms dups;
   246   in axioms' end);
   247 
   248 in
   249 
   250 val add_axioms = gen_add_axioms read_axm;
   251 val add_axioms_i = gen_add_axioms cert_axm;
   252 
   253 end;
   254 
   255 
   256 
   257 (** add constant definitions **)
   258 
   259 (* overloading *)
   260 
   261 datatype overloading = Clean | Implicit | Useless;
   262 
   263 fun overloading thy overloaded declT defT =
   264   let
   265     val defT' = Term.incr_tvar (maxidx_of_typ declT + 1) (Type.varifyT defT);
   266   in
   267     if Sign.typ_instance thy (declT, defT') then Clean
   268     else if Sign.typ_instance thy (Type.strip_sorts declT, Type.strip_sorts defT') then Useless
   269     else if overloaded then Clean
   270     else Implicit
   271   end;
   272 
   273 
   274 (* dest_def *)
   275 
   276 fun dest_def pp tm =
   277   let
   278     fun err msg = raise TERM (msg, [tm]);
   279 
   280     val (lhs, rhs) = Logic.dest_equals (Logic.strip_imp_concl tm)
   281       handle TERM _ => err "Not a meta-equality (==)";
   282     val (head, args) = Term.strip_comb lhs;
   283     val (c, T) = Term.dest_Const head
   284       handle TERM _ => err "Head of lhs not a constant";
   285 
   286     fun dest_free (Free (x, _)) = x
   287       | dest_free (Const ("TYPE", Type ("itself", [TFree (x, _)]))) = x
   288       | dest_free _ = raise Match;
   289 
   290     val show_terms = commas_quote o map (Pretty.string_of_term pp);
   291     val show_frees = commas_quote o map dest_free;
   292     val show_tfrees = commas_quote o map fst;
   293 
   294     val lhs_nofrees = filter (not o can dest_free) args;
   295     val lhs_dups = duplicates args;
   296     val rhs_extras = term_frees rhs |> fold (remove op =) args;
   297     val rhs_extrasT = term_tfrees rhs |> fold (remove op =) (typ_tfrees T);
   298   in
   299     if not (null lhs_nofrees) then
   300       err ("Non-variables as arguments on lhs: " ^ show_terms lhs_nofrees)
   301     else if not (null lhs_dups) then
   302       err ("Duplicate variables on lhs: " ^ show_frees lhs_dups)
   303     else if not (null rhs_extras) then
   304       err ("Extra variables on rhs: " ^ show_frees rhs_extras)
   305     else if not (null rhs_extrasT) then
   306       err ("Extra type variables on rhs: " ^ show_tfrees rhs_extrasT)
   307     else if exists_Const (equal (c, T)) rhs then
   308       err ("Constant to be defined occurs on rhs")
   309     else ((c, T), rhs)
   310   end;
   311 
   312 
   313 (* check_def *)
   314 
   315 fun declare thy c defs =      (* FIXME move to defs.ML *)
   316   let val T = Sign.the_const_type thy c
   317   in if_none (try (Defs.declare defs) (c, T)) defs end;
   318 
   319 fun check_def thy overloaded (bname, tm) defs =
   320   let
   321     val pp = Sign.pp thy;
   322 
   323     fun err msg = error (Pretty.string_of (Pretty.chunks
   324      [Pretty.str msg, Pretty.block
   325       [Pretty.str ("The error(s) above occurred in definition " ^ quote bname ^ ":"),
   326         Pretty.fbrk, Pretty.quote (Pretty.term pp tm)]]));
   327 
   328     fun prt_const (c, T) =
   329      [Pretty.str c, Pretty.str " ::", Pretty.brk 1,
   330       Pretty.quote (Pretty.typ pp (Type.freeze_type T))];
   331     fun string_of_def const txt =
   332       [Pretty.block (Pretty.str "Definition of " :: pretty_const pp const), Pretty.str txt]
   333       |> Pretty.chunks |> Pretty.string_of;
   334 
   335     val ((c, defT), rhs) = dest_def pp tm handle TERM (msg, _) => err msg;
   336     val rhs_consts = Term.term_constsT rhs;
   337     val declT = Sign.the_const_type thy c;
   338 
   339     val _ =
   340       (case overloading thy overloaded declT defT of
   341         Clean => ()
   342       | Implicit => warning (string_of_def (c, defT)
   343           ("is strictly less general than the declared type (see " ^ quote bname ^ ")"))
   344       | Useless => err (Library.setmp show_sorts true (string_of_def (c, defT))
   345           "imposes additional sort constraints on the declared type of the constant"));
   346 
   347     val decl_defs = defs |> declare thy c |> fold (declare thy) (map #1 rhs_consts);
   348   in
   349     Defs.define decl_defs (c, defT) (Sign.full_name thy bname) rhs_consts
   350       (* FIXME produce errors in defs.ML *)
   351       handle Defs.DEFS msg => err ("DEFS: " ^ msg)   (* FIXME sys_error!? *)
   352         | Defs.CIRCULAR path => err (defs_circular pp path)
   353         | Defs.INFINITE_CHAIN path => err (defs_infinite_chain pp path)
   354         | Defs.CLASH (_, def1, def2) => err (defs_clash def1 def2)
   355         | Defs.FINAL const => err (defs_final pp const)
   356   end;
   357 
   358 
   359 (* add_defs(_i) *)
   360 
   361 local
   362 
   363 fun gen_add_defs prep_axm overloaded raw_axms thy =
   364   let val axms = map (prep_axm thy) raw_axms in
   365     thy
   366     |> map_defs (fold (check_def thy overloaded) axms)
   367     |> add_axioms_i axms
   368   end;
   369 
   370 in
   371 
   372 val add_defs_i = gen_add_defs cert_axm;
   373 val add_defs = gen_add_defs read_axm;
   374 
   375 end;
   376 
   377 
   378 (* add_finals(_i) *)
   379 
   380 local
   381 
   382 fun gen_add_finals prep_term overloaded raw_terms thy =
   383   let
   384     fun finalize tm finals =
   385       let
   386         fun err msg = raise TERM (msg, [tm]);    (* FIXME error!? *)
   387         val (c, defT) =
   388           (case tm of Const x => x
   389           | Free _ => err "Attempt to finalize variable (or undeclared constant)"
   390           | _ => err "Attempt to finalize non-constant term");
   391         val declT = Sign.the_const_type thy c
   392           handle TYPE (msg, _, _) => err msg;
   393         val _ =    (* FIXME unify messages with defs *)
   394           (case overloading thy overloaded declT defT of
   395             Clean => ()
   396           | Implicit => warning ("Finalizing " ^ quote c ^
   397               " at a strictly less general type than declared")
   398           | Useless => err "Sort constraints stronger than declared");
   399       in Defs.finalize (if_none (try (Defs.declare finals) (c, declT)) finals) (c, defT) end;
   400   in thy |> map_defs (fold finalize (map (prep_term thy) raw_terms)) end;
   401 
   402 fun read_term thy = Sign.simple_read_term thy TypeInfer.logicT;
   403 fun cert_term thy = #1 o Sign.certify_term (Sign.pp thy) thy;
   404 
   405 in
   406 
   407 val add_finals = gen_add_finals read_term;
   408 val add_finals_i = gen_add_finals cert_term;
   409 
   410 end;
   411 
   412 
   413 
   414 (** add oracle **)
   415 
   416 fun add_oracle (bname, oracle) thy = thy |> map_oracles (fn oracles =>
   417   NameSpace.extend_table (Sign.naming_of thy) (oracles, [(bname, (oracle, stamp ()))])
   418     handle Symtab.DUPS dups => err_dup_oras dups);
   419 
   420 end;
   421 
   422 structure BasicTheory: BASIC_THEORY = Theory;
   423 open BasicTheory;