src/HOLCF/Tools/fixrec_package.ML
author haftmann
Sun Jun 21 08:38:58 2009 +0200 (2009-06-21)
changeset 31738 7b9b9ba532ca
parent 31177 c39994cb152a
permissions -rw-r--r--
discontinued ancient tradition to suffix certain ML module names with "_package"
haftmann@31738
     1
(*  Title:      HOLCF/Tools/fixrec.ML
wenzelm@23152
     2
    Author:     Amber Telfer and Brian Huffman
wenzelm@23152
     3
wenzelm@23152
     4
Recursive function definition package for HOLCF.
wenzelm@23152
     5
*)
wenzelm@23152
     6
haftmann@31738
     7
signature FIXREC =
wenzelm@23152
     8
sig
wenzelm@30485
     9
  val add_fixrec: bool -> (binding * typ option * mixfix) list
wenzelm@30485
    10
    -> (Attrib.binding * term) list -> local_theory -> local_theory
wenzelm@30485
    11
  val add_fixrec_cmd: bool -> (binding * string option * mixfix) list
huffman@30158
    12
    -> (Attrib.binding * string) list -> local_theory -> local_theory
wenzelm@30485
    13
  val add_fixpat: Thm.binding * term list -> theory -> theory
wenzelm@30485
    14
  val add_fixpat_cmd: Attrib.binding * string list -> theory -> theory
huffman@30131
    15
  val add_matchers: (string * string) list -> theory -> theory
huffman@30131
    16
  val setup: theory -> theory
wenzelm@23152
    17
end;
wenzelm@23152
    18
haftmann@31738
    19
structure Fixrec :> FIXREC =
wenzelm@23152
    20
struct
wenzelm@23152
    21
huffman@31095
    22
val def_cont_fix_eq = @{thm def_cont_fix_eq};
huffman@31095
    23
val def_cont_fix_ind = @{thm def_cont_fix_ind};
wenzelm@23152
    24
wenzelm@23152
    25
wenzelm@23152
    26
fun fixrec_err s = error ("fixrec definition error:\n" ^ s);
wenzelm@23152
    27
fun fixrec_eq_err thy s eq =
wenzelm@26939
    28
  fixrec_err (s ^ "\nin\n" ^ quote (Syntax.string_of_term_global thy eq));
wenzelm@23152
    29
huffman@30132
    30
(*************************************************************************)
huffman@30132
    31
(***************************** building types ****************************)
huffman@30132
    32
(*************************************************************************)
huffman@30132
    33
wenzelm@23152
    34
(* ->> is taken from holcf_logic.ML *)
huffman@30132
    35
fun cfunT (T, U) = Type(@{type_name "->"}, [T, U]);
huffman@30132
    36
huffman@30132
    37
infixr 6 ->>; val (op ->>) = cfunT;
huffman@30132
    38
huffman@30912
    39
fun cfunsT (Ts, U) = foldr cfunT U Ts;
huffman@30912
    40
huffman@30132
    41
fun dest_cfunT (Type(@{type_name "->"}, [T, U])) = (T, U)
huffman@30132
    42
  | dest_cfunT T = raise TYPE ("dest_cfunT", [T], []);
huffman@30132
    43
huffman@30132
    44
fun binder_cfun (Type(@{type_name "->"},[T, U])) = T :: binder_cfun U
huffman@30132
    45
  | binder_cfun _   =  [];
huffman@30132
    46
huffman@30132
    47
fun body_cfun (Type(@{type_name "->"},[T, U])) = body_cfun U
huffman@30132
    48
  | body_cfun T   =  T;
wenzelm@23152
    49
huffman@30132
    50
fun strip_cfun T : typ list * typ =
huffman@30132
    51
  (binder_cfun T, body_cfun T);
huffman@30132
    52
huffman@30132
    53
fun maybeT T = Type(@{type_name "maybe"}, [T]);
huffman@30132
    54
huffman@30132
    55
fun dest_maybeT (Type(@{type_name "maybe"}, [T])) = T
huffman@30132
    56
  | dest_maybeT T = raise TYPE ("dest_maybeT", [T], []);
huffman@30132
    57
huffman@31095
    58
fun tupleT [] = HOLogic.unitT
huffman@30132
    59
  | tupleT [T] = T
huffman@30132
    60
  | tupleT (T :: Ts) = HOLogic.mk_prodT (T, tupleT Ts);
huffman@30132
    61
huffman@30912
    62
fun matchT (T, U) =
huffman@30912
    63
  body_cfun T ->> cfunsT (binder_cfun T, U) ->> U;
huffman@30912
    64
huffman@30132
    65
huffman@30132
    66
(*************************************************************************)
huffman@30132
    67
(***************************** building terms ****************************)
huffman@30132
    68
(*************************************************************************)
wenzelm@23152
    69
wenzelm@23152
    70
val mk_trp = HOLogic.mk_Trueprop;
wenzelm@23152
    71
wenzelm@23152
    72
(* splits a cterm into the right and lefthand sides of equality *)
wenzelm@23152
    73
fun dest_eqs t = HOLogic.dest_eq (HOLogic.dest_Trueprop t);
wenzelm@23152
    74
wenzelm@23152
    75
(* similar to Thm.head_of, but for continuous application *)
huffman@26045
    76
fun chead_of (Const(@{const_name Rep_CFun},_)$f$t) = chead_of f
wenzelm@23152
    77
  | chead_of u = u;
wenzelm@23152
    78
huffman@30132
    79
fun capply_const (S, T) =
huffman@30132
    80
  Const(@{const_name Rep_CFun}, (S ->> T) --> (S --> T));
huffman@30132
    81
huffman@30132
    82
fun cabs_const (S, T) =
huffman@30132
    83
  Const(@{const_name Abs_CFun}, (S --> T) --> (S ->> T));
huffman@30132
    84
huffman@31095
    85
fun mk_cabs t =
huffman@31095
    86
  let val T = Term.fastype_of t
huffman@31095
    87
  in cabs_const (Term.domain_type T, Term.range_type T) $ t end
huffman@31095
    88
huffman@30132
    89
fun mk_capply (t, u) =
huffman@30132
    90
  let val (S, T) =
huffman@30132
    91
    case Term.fastype_of t of
huffman@30132
    92
        Type(@{type_name "->"}, [S, T]) => (S, T)
huffman@30132
    93
      | _ => raise TERM ("mk_capply " ^ ML_Syntax.print_list ML_Syntax.print_term [t, u], [t, u]);
huffman@30132
    94
  in capply_const (S, T) $ t $ u end;
huffman@30132
    95
huffman@30132
    96
infix 0 ==;  val (op ==) = Logic.mk_equals;
huffman@30132
    97
infix 1 ===; val (op ===) = HOLogic.mk_eq;
huffman@30132
    98
infix 9 `  ; val (op `) = mk_capply;
huffman@30132
    99
wenzelm@23152
   100
(* builds the expression (LAM v. rhs) *)
huffman@30132
   101
fun big_lambda v rhs =
huffman@30132
   102
  cabs_const (Term.fastype_of v, Term.fastype_of rhs) $ Term.lambda v rhs;
wenzelm@23152
   103
wenzelm@23152
   104
(* builds the expression (LAM v1 v2 .. vn. rhs) *)
wenzelm@23152
   105
fun big_lambdas [] rhs = rhs
wenzelm@23152
   106
  | big_lambdas (v::vs) rhs = big_lambda v (big_lambdas vs rhs);
wenzelm@23152
   107
huffman@30132
   108
fun mk_return t =
huffman@30132
   109
  let val T = Term.fastype_of t
huffman@30132
   110
  in Const(@{const_name Fixrec.return}, T ->> maybeT T) ` t end;
huffman@30132
   111
huffman@30132
   112
fun mk_bind (t, u) =
huffman@30132
   113
  let val (T, mU) = dest_cfunT (Term.fastype_of u);
huffman@30132
   114
      val bindT = maybeT T ->> (T ->> mU) ->> mU;
huffman@30132
   115
  in Const(@{const_name Fixrec.bind}, bindT) ` t ` u end;
huffman@30132
   116
huffman@30132
   117
fun mk_mplus (t, u) =
huffman@30132
   118
  let val mT = Term.fastype_of t
huffman@30132
   119
  in Const(@{const_name Fixrec.mplus}, mT ->> mT ->> mT) ` t ` u end;
huffman@30132
   120
huffman@30132
   121
fun mk_run t =
huffman@30132
   122
  let val mT = Term.fastype_of t
huffman@30132
   123
      val T = dest_maybeT mT
huffman@30132
   124
  in Const(@{const_name Fixrec.run}, mT ->> T) ` t end;
huffman@30132
   125
huffman@30132
   126
fun mk_fix t =
huffman@30132
   127
  let val (T, _) = dest_cfunT (Term.fastype_of t)
huffman@30132
   128
  in Const(@{const_name fix}, (T ->> T) ->> T) ` t end;
wenzelm@23152
   129
huffman@31095
   130
fun mk_cont t =
huffman@31095
   131
  let val T = Term.fastype_of t
huffman@31095
   132
  in Const(@{const_name cont}, T --> HOLogic.boolT) $ t end;
huffman@31095
   133
huffman@31095
   134
val mk_fst = HOLogic.mk_fst
huffman@31095
   135
val mk_snd = HOLogic.mk_snd
huffman@31095
   136
huffman@31095
   137
(* builds the expression (v1,v2,..,vn) *)
huffman@31095
   138
fun mk_tuple [] = HOLogic.unit
huffman@31095
   139
|   mk_tuple (t::[]) = t
huffman@31095
   140
|   mk_tuple (t::ts) = HOLogic.mk_prod (t, mk_tuple ts);
huffman@31095
   141
huffman@31095
   142
(* builds the expression (%(v1,v2,..,vn). rhs) *)
huffman@31095
   143
fun lambda_tuple [] rhs = Term.lambda (Free("unit", HOLogic.unitT)) rhs
huffman@31095
   144
  | lambda_tuple (v::[]) rhs = Term.lambda v rhs
huffman@31095
   145
  | lambda_tuple (v::vs) rhs =
huffman@31095
   146
      HOLogic.mk_split (Term.lambda v (lambda_tuple vs rhs));
huffman@31095
   147
huffman@31095
   148
wenzelm@23152
   149
(*************************************************************************)
wenzelm@23152
   150
(************* fixed-point definitions and unfolding theorems ************)
wenzelm@23152
   151
(*************************************************************************)
wenzelm@23152
   152
huffman@30158
   153
fun add_fixdefs
huffman@30158
   154
  (fixes : ((binding * typ) * mixfix) list)
huffman@30158
   155
  (spec : (Attrib.binding * term) list)
huffman@30158
   156
  (lthy : local_theory) =
wenzelm@23152
   157
  let
huffman@31095
   158
    val thy = ProofContext.theory_of lthy;
wenzelm@30223
   159
    val names = map (Binding.name_of o fst o fst) fixes;
huffman@30158
   160
    val all_names = space_implode "_" names;
huffman@30158
   161
    val (lhss,rhss) = ListPair.unzip (map (dest_eqs o snd) spec);
huffman@31095
   162
    val functional = lambda_tuple lhss (mk_tuple rhss);
huffman@31095
   163
    val fixpoint = mk_fix (mk_cabs functional);
wenzelm@23152
   164
    
huffman@31095
   165
    val cont_thm =
huffman@31095
   166
      Goal.prove lthy [] [] (mk_trp (mk_cont functional))
huffman@31095
   167
        (K (simp_tac (local_simpset_of lthy) 1));
huffman@31095
   168
huffman@30158
   169
    fun one_def (l as Free(n,_)) r =
wenzelm@30364
   170
          let val b = Long_Name.base_name n
huffman@30158
   171
          in ((Binding.name (b^"_def"), []), r) end
wenzelm@23152
   172
      | one_def _ _ = fixrec_err "fixdefs: lhs not of correct form";
wenzelm@23152
   173
    fun defs [] _ = []
wenzelm@23152
   174
      | defs (l::[]) r = [one_def l r]
huffman@31095
   175
      | defs (l::ls) r = one_def l (mk_fst r) :: defs ls (mk_snd r);
huffman@30158
   176
    val fixdefs = defs lhss fixpoint;
huffman@30158
   177
    val define_all = fold_map (LocalTheory.define Thm.definitionK);
huffman@30158
   178
    val (fixdef_thms : (term * (string * thm)) list, lthy') = lthy
huffman@30158
   179
      |> define_all (map (apfst fst) fixes ~~ fixdefs);
huffman@31095
   180
    fun pair_equalI (thm1, thm2) = @{thm Pair_equalI} OF [thm1, thm2];
huffman@31095
   181
    val tuple_fixdef_thm = foldr1 pair_equalI (map (snd o snd) fixdef_thms);
huffman@31095
   182
    val P = Var (("P", 0), map Term.fastype_of lhss ---> HOLogic.boolT);
huffman@31095
   183
    val predicate = lambda_tuple lhss (list_comb (P, lhss));
huffman@31095
   184
    val tuple_induct_thm = (def_cont_fix_ind OF [tuple_fixdef_thm, cont_thm])
huffman@31095
   185
      |> Drule.instantiate' [] [SOME (Thm.cterm_of thy predicate)]
huffman@31095
   186
      |> LocalDefs.unfold lthy @{thms split_paired_all split_conv split_strict};
huffman@31095
   187
    val tuple_unfold_thm = (def_cont_fix_eq OF [tuple_fixdef_thm, cont_thm])
huffman@31095
   188
      |> LocalDefs.unfold lthy' @{thms split_conv};
wenzelm@23152
   189
    fun unfolds [] thm = []
wenzelm@23152
   190
      | unfolds (n::[]) thm = [(n^"_unfold", thm)]
wenzelm@23152
   191
      | unfolds (n::ns) thm = let
huffman@31095
   192
          val thmL = thm RS @{thm Pair_eqD1};
huffman@31095
   193
          val thmR = thm RS @{thm Pair_eqD2};
wenzelm@23152
   194
        in (n^"_unfold", thmL) :: unfolds ns thmR end;
huffman@31095
   195
    val unfold_thms = unfolds names tuple_unfold_thm;
huffman@30158
   196
    fun mk_note (n, thm) = ((Binding.name n, []), [thm]);
huffman@30158
   197
    val (thmss, lthy'') = lthy'
haftmann@31177
   198
      |> fold_map (LocalTheory.note Thm.generatedK o mk_note)
huffman@31095
   199
        ((all_names ^ "_induct", tuple_induct_thm) :: unfold_thms);
wenzelm@23152
   200
  in
huffman@30158
   201
    (lthy'', names, fixdef_thms, map snd unfold_thms)
wenzelm@23152
   202
  end;
wenzelm@23152
   203
wenzelm@23152
   204
(*************************************************************************)
wenzelm@23152
   205
(*********** monadic notation and pattern matching compilation ***********)
wenzelm@23152
   206
(*************************************************************************)
wenzelm@23152
   207
huffman@30131
   208
structure FixrecMatchData = TheoryDataFun (
huffman@30131
   209
  type T = string Symtab.table;
huffman@30131
   210
  val empty = Symtab.empty;
huffman@30131
   211
  val copy = I;
huffman@30131
   212
  val extend = I;
huffman@30131
   213
  fun merge _ tabs : T = Symtab.merge (K true) tabs;
huffman@30131
   214
);
huffman@30131
   215
huffman@30131
   216
(* associate match functions with pattern constants *)
huffman@30131
   217
fun add_matchers ms = FixrecMatchData.map (fold Symtab.update ms);
huffman@30131
   218
huffman@30157
   219
fun taken_names (t : term) : bstring list =
huffman@30157
   220
  let
wenzelm@30364
   221
    fun taken (Const(a,_), bs) = insert (op =) (Long_Name.base_name a) bs
huffman@30157
   222
      | taken (Free(a,_) , bs) = insert (op =) a bs
huffman@30157
   223
      | taken (f $ u     , bs) = taken (f, taken (u, bs))
huffman@30157
   224
      | taken (Abs(a,_,t), bs) = taken (t, insert (op =) a bs)
huffman@30157
   225
      | taken (_         , bs) = bs;
huffman@30157
   226
  in
huffman@30157
   227
    taken (t, [])
huffman@30157
   228
  end;
wenzelm@23152
   229
wenzelm@23152
   230
(* builds a monadic term for matching a constructor pattern *)
huffman@30131
   231
fun pre_build match_name pat rhs vs taken =
wenzelm@23152
   232
  case pat of
huffman@26045
   233
    Const(@{const_name Rep_CFun},_)$f$(v as Free(n,T)) =>
huffman@30131
   234
      pre_build match_name f rhs (v::vs) taken
huffman@26045
   235
  | Const(@{const_name Rep_CFun},_)$f$x =>
huffman@30131
   236
      let val (rhs', v, taken') = pre_build match_name x rhs [] taken;
huffman@30131
   237
      in pre_build match_name f rhs' (v::vs) taken' end
wenzelm@23152
   238
  | Const(c,T) =>
wenzelm@23152
   239
      let
wenzelm@23152
   240
        val n = Name.variant taken "v";
huffman@26045
   241
        fun result_type (Type(@{type_name "->"},[_,T])) (x::xs) = result_type T xs
wenzelm@23152
   242
          | result_type T _ = T;
wenzelm@23152
   243
        val v = Free(n, result_type T vs);
huffman@30912
   244
        val m = Const(match_name c, matchT (T, fastype_of rhs));
huffman@30912
   245
        val k = big_lambdas vs rhs;
wenzelm@23152
   246
      in
huffman@30912
   247
        (m`v`k, v, n::taken)
wenzelm@23152
   248
      end
wenzelm@23152
   249
  | Free(n,_) => fixrec_err ("expected constructor, found free variable " ^ quote n)
wenzelm@23152
   250
  | _ => fixrec_err "pre_build: invalid pattern";
wenzelm@23152
   251
wenzelm@23152
   252
(* builds a monadic term for matching a function definition pattern *)
wenzelm@23152
   253
(* returns (name, arity, matcher) *)
huffman@30131
   254
fun building match_name pat rhs vs taken =
wenzelm@23152
   255
  case pat of
huffman@26045
   256
    Const(@{const_name Rep_CFun}, _)$f$(v as Free(n,T)) =>
huffman@30131
   257
      building match_name f rhs (v::vs) taken
huffman@26045
   258
  | Const(@{const_name Rep_CFun}, _)$f$x =>
huffman@30131
   259
      let val (rhs', v, taken') = pre_build match_name x rhs [] taken;
huffman@30131
   260
      in building match_name f rhs' (v::vs) taken' end
huffman@30158
   261
  | Free(_,_) => ((pat, length vs), big_lambdas vs rhs)
huffman@30158
   262
  | Const(_,_) => ((pat, length vs), big_lambdas vs rhs)
huffman@30158
   263
  | _ => fixrec_err ("function is not declared as constant in theory: "
huffman@30158
   264
                    ^ ML_Syntax.print_term pat);
wenzelm@23152
   265
huffman@30158
   266
fun strip_alls t =
huffman@30158
   267
  if Logic.is_all t then strip_alls (snd (Logic.dest_all t)) else t;
huffman@30158
   268
huffman@30158
   269
fun match_eq match_name eq =
huffman@30158
   270
  let
huffman@30158
   271
    val (lhs,rhs) = dest_eqs (Logic.strip_imp_concl (strip_alls eq));
huffman@30131
   272
  in
huffman@30157
   273
    building match_name lhs (mk_return rhs) [] (taken_names eq)
huffman@30131
   274
  end;
wenzelm@23152
   275
wenzelm@23152
   276
(* returns the sum (using +++) of the terms in ms *)
wenzelm@23152
   277
(* also applies "run" to the result! *)
wenzelm@23152
   278
fun fatbar arity ms =
wenzelm@23152
   279
  let
huffman@30132
   280
    fun LAM_Ts 0 t = ([], Term.fastype_of t)
huffman@30132
   281
      | LAM_Ts n (_ $ Abs(_,T,t)) =
huffman@30132
   282
          let val (Ts, U) = LAM_Ts (n-1) t in (T::Ts, U) end
huffman@30132
   283
      | LAM_Ts _ _ = fixrec_err "fatbar: internal error, not enough LAMs";
wenzelm@23152
   284
    fun unLAM 0 t = t
wenzelm@23152
   285
      | unLAM n (_$Abs(_,_,t)) = unLAM (n-1) t
wenzelm@23152
   286
      | unLAM _ _ = fixrec_err "fatbar: internal error, not enough LAMs";
huffman@30132
   287
    fun reLAM ([], U) t = t
huffman@30132
   288
      | reLAM (T::Ts, U) t = reLAM (Ts, T ->> U) (cabs_const(T,U)$Abs("",T,t));
huffman@30132
   289
    val msum = foldr1 mk_mplus (map (unLAM arity) ms);
huffman@30132
   290
    val (Ts, U) = LAM_Ts arity (hd ms)
wenzelm@23152
   291
  in
huffman@30132
   292
    reLAM (rev Ts, dest_maybeT U) (mk_run msum)
wenzelm@23152
   293
  end;
wenzelm@23152
   294
wenzelm@23152
   295
(* this is the pattern-matching compiler function *)
huffman@30158
   296
fun compile_pats match_name eqs =
wenzelm@23152
   297
  let
huffman@30158
   298
    val (((n::names),(a::arities)),mats) =
huffman@30158
   299
      apfst ListPair.unzip (ListPair.unzip (map (match_eq match_name) eqs));
wenzelm@23152
   300
    val cname = if forall (fn x => n=x) names then n
wenzelm@23152
   301
          else fixrec_err "all equations in block must define the same function";
wenzelm@23152
   302
    val arity = if forall (fn x => a=x) arities then a
wenzelm@23152
   303
          else fixrec_err "all equations in block must have the same arity";
wenzelm@23152
   304
    val rhs = fatbar arity mats;
wenzelm@23152
   305
  in
huffman@30132
   306
    mk_trp (cname === rhs)
wenzelm@23152
   307
  end;
wenzelm@23152
   308
wenzelm@23152
   309
(*************************************************************************)
wenzelm@23152
   310
(********************** Proving associated theorems **********************)
wenzelm@23152
   311
(*************************************************************************)
wenzelm@23152
   312
wenzelm@23152
   313
(* proves a block of pattern matching equations as theorems, using unfold *)
huffman@30158
   314
fun make_simps lthy (unfold_thm, eqns : (Attrib.binding * term) list) =
wenzelm@23152
   315
  let
huffman@30158
   316
    val tacs =
huffman@30158
   317
      [rtac (unfold_thm RS @{thm ssubst_lhs}) 1,
huffman@30158
   318
       asm_simp_tac (local_simpset_of lthy) 1];
huffman@30158
   319
    fun prove_term t = Goal.prove lthy [] [] t (K (EVERY tacs));
huffman@30158
   320
    fun prove_eqn (bind, eqn_t) = (bind, prove_term eqn_t);
wenzelm@23152
   321
  in
wenzelm@23152
   322
    map prove_eqn eqns
wenzelm@23152
   323
  end;
wenzelm@23152
   324
wenzelm@23152
   325
(*************************************************************************)
wenzelm@23152
   326
(************************* Main fixrec function **************************)
wenzelm@23152
   327
(*************************************************************************)
wenzelm@23152
   328
huffman@30158
   329
local
haftmann@31738
   330
(* code adapted from HOL/Tools/primrec.ML *)
huffman@30158
   331
huffman@30158
   332
fun gen_fixrec
huffman@30158
   333
  (set_group : bool)
wenzelm@30485
   334
  prep_spec
huffman@30158
   335
  (strict : bool)
huffman@30158
   336
  raw_fixes
huffman@30158
   337
  raw_spec
huffman@30158
   338
  (lthy : local_theory) =
wenzelm@23152
   339
  let
huffman@30158
   340
    val (fixes : ((binding * typ) * mixfix) list,
huffman@30158
   341
         spec : (Attrib.binding * term) list) =
wenzelm@30485
   342
          fst (prep_spec raw_fixes raw_spec lthy);
huffman@30158
   343
    val chead_of_spec =
huffman@30158
   344
      chead_of o fst o dest_eqs o Logic.strip_imp_concl o strip_alls o snd;
huffman@30158
   345
    fun name_of (Free (n, _)) = n
huffman@30158
   346
      | name_of t = fixrec_err ("unknown term");
huffman@30158
   347
    val all_names = map (name_of o chead_of_spec) spec;
huffman@30158
   348
    val names = distinct (op =) all_names;
huffman@30158
   349
    fun block_of_name n =
huffman@30158
   350
      map_filter
huffman@30158
   351
        (fn (m,eq) => if m = n then SOME eq else NONE)
huffman@30158
   352
        (all_names ~~ spec);
huffman@30158
   353
    val blocks = map block_of_name names;
huffman@30158
   354
huffman@30158
   355
    val matcher_tab = FixrecMatchData.get (ProofContext.theory_of lthy);
huffman@30131
   356
    fun match_name c =
huffman@30158
   357
      case Symtab.lookup matcher_tab c of SOME m => m
huffman@30158
   358
        | NONE => fixrec_err ("unknown pattern constructor: " ^ c);
huffman@30131
   359
huffman@30158
   360
    val matches = map (compile_pats match_name) (map (map snd) blocks);
huffman@30158
   361
    val spec' = map (pair Attrib.empty_binding) matches;
huffman@30158
   362
    val (lthy', cnames, fixdef_thms, unfold_thms) =
huffman@30158
   363
      add_fixdefs fixes spec' lthy;
wenzelm@23152
   364
  in
wenzelm@23152
   365
    if strict then let (* only prove simp rules if strict = true *)
huffman@30158
   366
      val simps : (Attrib.binding * thm) list list =
huffman@30158
   367
        map (make_simps lthy') (unfold_thms ~~ blocks);
huffman@30158
   368
      fun mk_bind n : Attrib.binding =
huffman@30158
   369
       (Binding.name (n ^ "_simps"),
huffman@30158
   370
         [Attrib.internal (K Simplifier.simp_add)]);
huffman@30158
   371
      val simps1 : (Attrib.binding * thm list) list =
huffman@30158
   372
        map (fn (n,xs) => (mk_bind n, map snd xs)) (names ~~ simps);
huffman@30158
   373
      val simps2 : (Attrib.binding * thm list) list =
huffman@30158
   374
        map (apsnd (fn thm => [thm])) (List.concat simps);
huffman@30158
   375
      val (_, lthy'') = lthy'
haftmann@31177
   376
        |> fold_map (LocalTheory.note Thm.generatedK) (simps1 @ simps2);
wenzelm@23152
   377
    in
huffman@30158
   378
      lthy''
wenzelm@23152
   379
    end
huffman@30158
   380
    else lthy'
wenzelm@23152
   381
  end;
wenzelm@23152
   382
huffman@30158
   383
in
wenzelm@23152
   384
wenzelm@30485
   385
val add_fixrec = gen_fixrec false Specification.check_spec;
wenzelm@30485
   386
val add_fixrec_cmd = gen_fixrec true Specification.read_spec;
huffman@30158
   387
huffman@30158
   388
end; (* local *)
wenzelm@23152
   389
wenzelm@23152
   390
(*************************************************************************)
wenzelm@23152
   391
(******************************** Fixpat *********************************)
wenzelm@23152
   392
(*************************************************************************)
wenzelm@23152
   393
wenzelm@23152
   394
fun fix_pat thy t = 
wenzelm@23152
   395
  let
wenzelm@23152
   396
    val T = fastype_of t;
wenzelm@23152
   397
    val eq = mk_trp (HOLogic.eq_const T $ t $ Var (("x",0),T));
wenzelm@23152
   398
    val cname = case chead_of t of Const(c,_) => c | _ =>
wenzelm@23152
   399
              fixrec_err "function is not declared as constant in theory";
wenzelm@26343
   400
    val unfold_thm = PureThy.get_thm thy (cname^"_unfold");
wenzelm@23152
   401
    val simp = Goal.prove_global thy [] [] eq
wenzelm@23152
   402
          (fn _ => EVERY [stac unfold_thm 1, simp_tac (simpset_of thy) 1]);
wenzelm@23152
   403
  in simp end;
wenzelm@23152
   404
wenzelm@23152
   405
fun gen_add_fixpat prep_term prep_attrib ((name, srcs), strings) thy =
wenzelm@23152
   406
  let
wenzelm@23152
   407
    val atts = map (prep_attrib thy) srcs;
wenzelm@23152
   408
    val ts = map (prep_term thy) strings;
wenzelm@23152
   409
    val simps = map (fix_pat thy) ts;
wenzelm@23152
   410
  in
haftmann@29585
   411
    (snd o PureThy.add_thmss [((name, simps), atts)]) thy
wenzelm@23152
   412
  end;
wenzelm@23152
   413
wenzelm@30485
   414
val add_fixpat = gen_add_fixpat Sign.cert_term (K I);
wenzelm@30485
   415
val add_fixpat_cmd = gen_add_fixpat Syntax.read_term_global Attrib.attribute;
wenzelm@23152
   416
wenzelm@23152
   417
wenzelm@23152
   418
(*************************************************************************)
wenzelm@23152
   419
(******************************** Parsers ********************************)
wenzelm@23152
   420
(*************************************************************************)
wenzelm@23152
   421
wenzelm@23152
   422
local structure P = OuterParse and K = OuterKeyword in
wenzelm@23152
   423
wenzelm@30485
   424
val _ = OuterSyntax.local_theory "fixrec" "define recursive functions (HOLCF)" K.thy_decl
wenzelm@30485
   425
  ((P.opt_keyword "permissive" >> not) -- P.fixes -- SpecParse.where_alt_specs
wenzelm@30485
   426
    >> (fn ((strict, fixes), specs) => add_fixrec_cmd strict fixes specs));
wenzelm@23152
   427
wenzelm@30485
   428
val _ = OuterSyntax.command "fixpat" "define rewrites for fixrec functions" K.thy_decl
wenzelm@30485
   429
  (SpecParse.specs >> (Toplevel.theory o add_fixpat_cmd));
huffman@30158
   430
  
wenzelm@30485
   431
end;
wenzelm@23152
   432
huffman@30131
   433
val setup = FixrecMatchData.init;
huffman@30131
   434
wenzelm@24867
   435
end;