src/HOL/Tools/recdef_package.ML
author paulson
Tue May 22 17:56:06 2007 +0200 (2007-05-22)
changeset 23075 69e30a7e8880
parent 22846 fb79144af9a3
child 24039 273698405054
permissions -rw-r--r--
Some hacks for SPASS format
     1 (*  Title:      HOL/Tools/recdef_package.ML
     2     ID:         $Id$
     3     Author:     Markus Wenzel, TU Muenchen
     4 
     5 Wrapper module for Konrad Slind's TFL package.
     6 *)
     7 
     8 signature RECDEF_PACKAGE =
     9 sig
    10   val quiet_mode: bool ref
    11   val get_recdef: theory -> string
    12     -> {simps: thm list, rules: thm list list, induct: thm, tcs: term list} option
    13   val get_hints: Proof.context -> {simps: thm list, congs: (string * thm) list, wfs: thm list}
    14   val simp_add: attribute
    15   val simp_del: attribute
    16   val cong_add: attribute
    17   val cong_del: attribute
    18   val wf_add: attribute
    19   val wf_del: attribute
    20   val add_recdef: bool -> xstring -> string -> ((bstring * string) * Attrib.src list) list ->
    21     Attrib.src option -> theory -> theory
    22       * {simps: thm list, rules: thm list list, induct: thm, tcs: term list}
    23   val add_recdef_i: bool -> xstring -> term -> ((bstring * term) * attribute list) list ->
    24     theory -> theory * {simps: thm list, rules: thm list list, induct: thm, tcs: term list}
    25   val defer_recdef: xstring -> string list -> (thmref * Attrib.src list) list
    26     -> theory -> theory * {induct_rules: thm}
    27   val defer_recdef_i: xstring -> term list -> (thm list * attribute list) list
    28     -> theory -> theory * {induct_rules: thm}
    29   val recdef_tc: bstring * Attrib.src list -> xstring -> int option -> local_theory -> Proof.state
    30   val recdef_tc_i: bstring * Attrib.src list -> string -> int option -> local_theory -> Proof.state
    31   val setup: theory -> theory
    32 end;
    33 
    34 structure RecdefPackage: RECDEF_PACKAGE =
    35 struct
    36 
    37 val quiet_mode = Tfl.quiet_mode;
    38 val message = Tfl.message;
    39 
    40 
    41 (** recdef hints **)
    42 
    43 (* type hints *)
    44 
    45 type hints = {simps: thm list, congs: (string * thm) list, wfs: thm list};
    46 
    47 fun mk_hints (simps, congs, wfs) = {simps = simps, congs = congs, wfs = wfs}: hints;
    48 fun map_hints f ({simps, congs, wfs}: hints) = mk_hints (f (simps, congs, wfs));
    49 
    50 fun map_simps f = map_hints (fn (simps, congs, wfs) => (f simps, congs, wfs));
    51 fun map_congs f = map_hints (fn (simps, congs, wfs) => (simps, f congs, wfs));
    52 fun map_wfs f = map_hints (fn (simps, congs, wfs) => (simps, congs, f wfs));
    53 
    54 fun pretty_hints ({simps, congs, wfs}: hints) =
    55  [Pretty.big_list "recdef simp hints:" (map Display.pretty_thm simps),
    56   Pretty.big_list "recdef cong hints:" (map Display.pretty_thm (map snd congs)),
    57   Pretty.big_list "recdef wf hints:" (map Display.pretty_thm wfs)];
    58 
    59 
    60 (* congruence rules *)
    61 
    62 local
    63 
    64 val cong_head =
    65   fst o Term.dest_Const o Term.head_of o fst o Logic.dest_equals o Thm.concl_of;
    66 
    67 fun prep_cong raw_thm =
    68   let val thm = safe_mk_meta_eq raw_thm in (cong_head thm, thm) end;
    69 
    70 in
    71 
    72 fun add_cong raw_thm congs =
    73   let
    74     val (c, thm) = prep_cong raw_thm;
    75     val _ = if AList.defined (op =) congs c
    76       then warning ("Overwriting recdef congruence rule for " ^ quote c)
    77       else ();
    78   in AList.update (op =) (c, thm) congs end;
    79 
    80 fun del_cong raw_thm congs =
    81   let
    82     val (c, thm) = prep_cong raw_thm;
    83     val _ = if AList.defined (op =) congs c
    84       then ()
    85       else warning ("No recdef congruence rule for " ^ quote c);
    86   in AList.delete (op =) c congs end;
    87 
    88 end;
    89 
    90 
    91 
    92 (** global and local recdef data **)
    93 
    94 (* theory data *)
    95 
    96 type recdef_info = {simps: thm list, rules: thm list list, induct: thm, tcs: term list};
    97 
    98 structure GlobalRecdefData = TheoryDataFun
    99 (
   100   type T = recdef_info Symtab.table * hints;
   101   val empty = (Symtab.empty, mk_hints ([], [], [])): T;
   102   val copy = I;
   103   val extend = I;
   104   fun merge _
   105    ((tab1, {simps = simps1, congs = congs1, wfs = wfs1}),
   106     (tab2, {simps = simps2, congs = congs2, wfs = wfs2})) : T =
   107       (Symtab.merge (K true) (tab1, tab2),
   108         mk_hints (Drule.merge_rules (simps1, simps2),
   109           AList.merge (op =) Thm.eq_thm (congs1, congs2),
   110           Drule.merge_rules (wfs1, wfs2)));
   111 );
   112 
   113 val get_recdef = Symtab.lookup o #1 o GlobalRecdefData.get;
   114 
   115 fun put_recdef name info thy =
   116   let
   117     val (tab, hints) = GlobalRecdefData.get thy;
   118     val tab' = Symtab.update_new (name, info) tab
   119       handle Symtab.DUP _ => error ("Duplicate recursive function definition " ^ quote name);
   120   in GlobalRecdefData.put (tab', hints) thy end;
   121 
   122 val get_global_hints = #2 o GlobalRecdefData.get;
   123 
   124 
   125 (* proof data *)
   126 
   127 structure LocalRecdefData = ProofDataFun
   128 (
   129   type T = hints;
   130   val init = get_global_hints;
   131 );
   132 
   133 val get_hints = LocalRecdefData.get;
   134 fun map_hints f = Context.mapping (GlobalRecdefData.map (apsnd f)) (LocalRecdefData.map f);
   135 
   136 
   137 (* attributes *)
   138 
   139 fun attrib f = Thm.declaration_attribute (map_hints o f);
   140 
   141 val simp_add = attrib (map_simps o Drule.add_rule);
   142 val simp_del = attrib (map_simps o Drule.del_rule);
   143 val cong_add = attrib (map_congs o add_cong);
   144 val cong_del = attrib (map_congs o del_cong);
   145 val wf_add = attrib (map_wfs o Drule.add_rule);
   146 val wf_del = attrib (map_wfs o Drule.del_rule);
   147 
   148 
   149 (* modifiers *)
   150 
   151 val recdef_simpN = "recdef_simp";
   152 val recdef_congN = "recdef_cong";
   153 val recdef_wfN = "recdef_wf";
   154 
   155 val recdef_modifiers =
   156  [Args.$$$ recdef_simpN -- Args.colon >> K ((I, simp_add): Method.modifier),
   157   Args.$$$ recdef_simpN -- Args.add -- Args.colon >> K (I, simp_add),
   158   Args.$$$ recdef_simpN -- Args.del -- Args.colon >> K (I, simp_del),
   159   Args.$$$ recdef_congN -- Args.colon >> K (I, cong_add),
   160   Args.$$$ recdef_congN -- Args.add -- Args.colon >> K (I, cong_add),
   161   Args.$$$ recdef_congN -- Args.del -- Args.colon >> K (I, cong_del),
   162   Args.$$$ recdef_wfN -- Args.colon >> K (I, wf_add),
   163   Args.$$$ recdef_wfN -- Args.add -- Args.colon >> K (I, wf_add),
   164   Args.$$$ recdef_wfN -- Args.del -- Args.colon >> K (I, wf_del)] @
   165   Clasimp.clasimp_modifiers;
   166 
   167 
   168 
   169 (** prepare_hints(_i) **)
   170 
   171 fun prepare_hints thy opt_src =
   172   let
   173     val ctxt0 = ProofContext.init thy;
   174     val ctxt =
   175       (case opt_src of
   176         NONE => ctxt0
   177       | SOME src => Method.only_sectioned_args recdef_modifiers I src ctxt0);
   178     val {simps, congs, wfs} = get_hints ctxt;
   179     val cs = local_claset_of ctxt;
   180     val ss = local_simpset_of ctxt addsimps simps;
   181   in (cs, ss, rev (map snd congs), wfs) end;
   182 
   183 fun prepare_hints_i thy () =
   184   let
   185     val ctxt0 = ProofContext.init thy;
   186     val {simps, congs, wfs} = get_global_hints thy;
   187   in (local_claset_of ctxt0, local_simpset_of ctxt0 addsimps simps, rev (map snd congs), wfs) end;
   188 
   189 
   190 
   191 (** add_recdef(_i) **)
   192 
   193 fun requires_recdef thy = Theory.requires thy "Recdef" "recursive functions";
   194 
   195 fun gen_add_recdef tfl_fn prep_att prep_hints not_permissive raw_name R eq_srcs hints thy =
   196   let
   197     val _ = requires_recdef thy;
   198 
   199     val name = Sign.intern_const thy raw_name;
   200     val bname = Sign.base_name name;
   201     val _ = message ("Defining recursive function " ^ quote name ^ " ...");
   202 
   203     val ((eq_names, eqs), raw_eq_atts) = apfst split_list (split_list eq_srcs);
   204     val eq_atts = map (map (prep_att thy)) raw_eq_atts;
   205 
   206     val (cs, ss, congs, wfs) = prep_hints thy hints;
   207     (*We must remove imp_cong to prevent looping when the induction rule
   208       is simplified. Many induction rules have nested implications that would
   209       give rise to looping conditional rewriting.*)
   210     val (thy, {rules = rules_idx, induct, tcs}) =
   211         tfl_fn not_permissive thy cs (ss delcongs [imp_cong])
   212                congs wfs name R eqs;
   213     val rules = (map o map) fst (partition_eq (eq_snd (op = : int * int -> bool)) rules_idx);
   214     val simp_att = if null tcs then [Simplifier.simp_add, RecfunCodegen.add NONE] else [];
   215 
   216     val ((simps' :: rules', [induct']), thy) =
   217       thy
   218       |> Theory.add_path bname
   219       |> PureThy.add_thmss
   220         ((("simps", List.concat rules), simp_att) :: ((eq_names ~~ rules) ~~ eq_atts))
   221       ||>> PureThy.add_thms [(("induct", induct), [])];
   222     val result = {simps = simps', rules = rules', induct = induct', tcs = tcs};
   223     val thy =
   224       thy
   225       |> put_recdef name result
   226       |> Theory.parent_path;
   227   in (thy, result) end;
   228 
   229 val add_recdef = gen_add_recdef Tfl.define Attrib.attribute prepare_hints;
   230 fun add_recdef_i x y z w = gen_add_recdef Tfl.define_i (K I) prepare_hints_i x y z w ();
   231 
   232 
   233 
   234 (** defer_recdef(_i) **)
   235 
   236 fun gen_defer_recdef tfl_fn app_thms raw_name eqs raw_congs thy =
   237   let
   238     val name = Sign.intern_const thy raw_name;
   239     val bname = Sign.base_name name;
   240 
   241     val _ = requires_recdef thy;
   242     val _ = message ("Deferred recursive function " ^ quote name ^ " ...");
   243 
   244     val (congs, thy1) = thy |> app_thms raw_congs;
   245     val (thy2, induct_rules) = tfl_fn thy1 congs name eqs;
   246     val ([induct_rules'], thy3) =
   247       thy2
   248       |> Theory.add_path bname
   249       |> PureThy.add_thms [(("induct_rules", induct_rules), [])]
   250       ||> Theory.parent_path;
   251   in (thy3, {induct_rules = induct_rules'}) end;
   252 
   253 val defer_recdef = gen_defer_recdef Tfl.defer IsarCmd.apply_theorems;
   254 val defer_recdef_i = gen_defer_recdef Tfl.defer_i IsarCmd.apply_theorems_i;
   255 
   256 
   257 
   258 (** recdef_tc(_i) **)
   259 
   260 fun gen_recdef_tc prep_att prep_name (bname, raw_atts) raw_name opt_i lthy =
   261   let
   262     val thy = ProofContext.theory_of lthy;
   263     val name = prep_name thy raw_name;
   264     val atts = map (prep_att thy) raw_atts;
   265     val tcs =
   266       (case get_recdef thy name of
   267         NONE => error ("No recdef definition of constant: " ^ quote name)
   268       | SOME {tcs, ...} => tcs);
   269     val i = the_default 1 opt_i;
   270     val tc = nth tcs (i - 1) handle Subscript =>
   271       error ("No termination condition #" ^ string_of_int i ^
   272         " in recdef definition of " ^ quote name);
   273   in
   274     Specification.theorem_i Thm.internalK NONE (K I) (bname, atts)
   275       [] (Element.Shows [(("", []), [(HOLogic.mk_Trueprop tc, [])])]) lthy
   276   end;
   277 
   278 val recdef_tc = gen_recdef_tc Attrib.intern_src Sign.intern_const;
   279 val recdef_tc_i = gen_recdef_tc (K I) (K I);
   280 
   281 
   282 
   283 (** package setup **)
   284 
   285 (* setup theory *)
   286 
   287 val setup =
   288   Attrib.add_attributes
   289    [(recdef_simpN, Attrib.add_del_args simp_add simp_del, "declaration of recdef simp rule"),
   290     (recdef_congN, Attrib.add_del_args cong_add cong_del, "declaration of recdef cong rule"),
   291     (recdef_wfN, Attrib.add_del_args wf_add wf_del, "declaration of recdef wf rule")];
   292 
   293 
   294 (* outer syntax *)
   295 
   296 local structure P = OuterParse and K = OuterKeyword in
   297 
   298 val hints =
   299   P.$$$ "(" |-- P.!!! (P.position (P.$$$ "hints" -- P.arguments) --| P.$$$ ")") >> Args.src;
   300 
   301 val recdef_decl =
   302   Scan.optional (P.$$$ "(" -- P.!!! (P.$$$ "permissive" -- P.$$$ ")") >> K false) true --
   303   P.name -- P.term -- Scan.repeat1 (SpecParse.opt_thm_name ":" -- P.prop) -- Scan.option hints
   304   >> (fn ((((p, f), R), eqs), src) => #1 o add_recdef p f R (map P.triple_swap eqs) src);
   305 
   306 val recdefP =
   307   OuterSyntax.command "recdef" "define general recursive functions (TFL)" K.thy_decl
   308     (recdef_decl >> Toplevel.theory);
   309 
   310 
   311 val defer_recdef_decl =
   312   P.name -- Scan.repeat1 P.prop --
   313   Scan.optional (P.$$$ "(" |-- P.$$$ "congs" |-- P.!!! (SpecParse.xthms1 --| P.$$$ ")")) []
   314   >> (fn ((f, eqs), congs) => #1 o defer_recdef f eqs congs);
   315 
   316 val defer_recdefP =
   317   OuterSyntax.command "defer_recdef" "defer general recursive functions (TFL)" K.thy_decl
   318     (defer_recdef_decl >> Toplevel.theory);
   319 
   320 val recdef_tcP =
   321   OuterSyntax.command "recdef_tc" "recommence proof of termination condition (TFL)" K.thy_goal
   322     (P.opt_target --
   323       SpecParse.opt_thm_name ":" -- P.xname -- Scan.option (P.$$$ "(" |-- P.nat --| P.$$$ ")")
   324       >> (fn (((loc, thm_name), name), i) =>
   325         Toplevel.print o Toplevel.local_theory_to_proof loc (recdef_tc thm_name name i)));
   326 
   327 
   328 val _ = OuterSyntax.add_keywords ["permissive", "congs", "hints"];
   329 val _ = OuterSyntax.add_parsers [recdefP, defer_recdefP, recdef_tcP];
   330 
   331 end;
   332 
   333 end;