src/HOLCF/Tools/fixrec_package.ML
author wenzelm
Tue Mar 03 18:32:01 2009 +0100 (2009-03-03)
changeset 30223 24d975352879
parent 30211 556d1810cdad
child 30242 aea5d7fa7ef5
permissions -rw-r--r--
renamed Binding.name_pos to Binding.make, renamed Binding.base_name to Binding.name_of, renamed Binding.map_base to Binding.map_name, added mandatory flag to Binding.qualify;
minor tuning;
wenzelm@23152
     1
(*  Title:      HOLCF/Tools/fixrec_package.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
wenzelm@23152
     7
signature FIXREC_PACKAGE =
wenzelm@23152
     8
sig
wenzelm@23152
     9
  val legacy_infer_term: theory -> term -> term
wenzelm@23152
    10
  val legacy_infer_prop: theory -> term -> term
huffman@30132
    11
huffman@30158
    12
  val add_fixrec: bool -> (binding * string option * mixfix) list
huffman@30158
    13
    -> (Attrib.binding * string) list -> local_theory -> local_theory
huffman@30158
    14
huffman@30158
    15
  val add_fixrec_i: bool -> (binding * typ option * mixfix) list
huffman@30158
    16
    -> (Attrib.binding * term) list -> local_theory -> local_theory
huffman@30158
    17
wenzelm@28084
    18
  val add_fixpat: Attrib.binding * string list -> theory -> theory
wenzelm@30211
    19
  val add_fixpat_i: Thm.binding * term list -> theory -> theory
huffman@30131
    20
  val add_matchers: (string * string) list -> theory -> theory
huffman@30131
    21
  val setup: theory -> theory
wenzelm@23152
    22
end;
wenzelm@23152
    23
wenzelm@23152
    24
structure FixrecPackage: FIXREC_PACKAGE =
wenzelm@23152
    25
struct
wenzelm@23152
    26
wenzelm@23152
    27
(* legacy type inference *)
huffman@30132
    28
(* used by the domain package *)
wenzelm@23152
    29
fun legacy_infer_term thy t =
wenzelm@24493
    30
  singleton (Syntax.check_terms (ProofContext.init thy)) (Sign.intern_term thy t);
wenzelm@23152
    31
wenzelm@24680
    32
fun legacy_infer_prop thy t = legacy_infer_term thy (TypeInfer.constrain propT t);
wenzelm@23152
    33
wenzelm@23152
    34
huffman@26045
    35
val fix_eq2 = @{thm fix_eq2};
huffman@26045
    36
val def_fix_ind = @{thm def_fix_ind};
wenzelm@23152
    37
wenzelm@23152
    38
wenzelm@23152
    39
fun fixrec_err s = error ("fixrec definition error:\n" ^ s);
wenzelm@23152
    40
fun fixrec_eq_err thy s eq =
wenzelm@26939
    41
  fixrec_err (s ^ "\nin\n" ^ quote (Syntax.string_of_term_global thy eq));
wenzelm@23152
    42
huffman@30132
    43
(*************************************************************************)
huffman@30132
    44
(***************************** building types ****************************)
huffman@30132
    45
(*************************************************************************)
huffman@30132
    46
wenzelm@23152
    47
(* ->> is taken from holcf_logic.ML *)
huffman@30132
    48
fun cfunT (T, U) = Type(@{type_name "->"}, [T, U]);
huffman@30132
    49
huffman@30132
    50
infixr 6 ->>; val (op ->>) = cfunT;
huffman@30132
    51
huffman@30132
    52
fun dest_cfunT (Type(@{type_name "->"}, [T, U])) = (T, U)
huffman@30132
    53
  | dest_cfunT T = raise TYPE ("dest_cfunT", [T], []);
huffman@30132
    54
huffman@30132
    55
fun binder_cfun (Type(@{type_name "->"},[T, U])) = T :: binder_cfun U
huffman@30132
    56
  | binder_cfun _   =  [];
huffman@30132
    57
huffman@30132
    58
fun body_cfun (Type(@{type_name "->"},[T, U])) = body_cfun U
huffman@30132
    59
  | body_cfun T   =  T;
wenzelm@23152
    60
huffman@30132
    61
fun strip_cfun T : typ list * typ =
huffman@30132
    62
  (binder_cfun T, body_cfun T);
huffman@30132
    63
huffman@30132
    64
fun maybeT T = Type(@{type_name "maybe"}, [T]);
huffman@30132
    65
huffman@30132
    66
fun dest_maybeT (Type(@{type_name "maybe"}, [T])) = T
huffman@30132
    67
  | dest_maybeT T = raise TYPE ("dest_maybeT", [T], []);
huffman@30132
    68
huffman@30132
    69
fun tupleT [] = @{typ "unit"}
huffman@30132
    70
  | tupleT [T] = T
huffman@30132
    71
  | tupleT (T :: Ts) = HOLogic.mk_prodT (T, tupleT Ts);
huffman@30132
    72
huffman@30132
    73
fun matchT T = body_cfun T ->> maybeT (tupleT (binder_cfun T));
huffman@30132
    74
huffman@30132
    75
(*************************************************************************)
huffman@30132
    76
(***************************** building terms ****************************)
huffman@30132
    77
(*************************************************************************)
wenzelm@23152
    78
wenzelm@23152
    79
val mk_trp = HOLogic.mk_Trueprop;
wenzelm@23152
    80
wenzelm@23152
    81
(* splits a cterm into the right and lefthand sides of equality *)
wenzelm@23152
    82
fun dest_eqs t = HOLogic.dest_eq (HOLogic.dest_Trueprop t);
wenzelm@23152
    83
wenzelm@23152
    84
(* similar to Thm.head_of, but for continuous application *)
huffman@26045
    85
fun chead_of (Const(@{const_name Rep_CFun},_)$f$t) = chead_of f
wenzelm@23152
    86
  | chead_of u = u;
wenzelm@23152
    87
huffman@30132
    88
fun capply_const (S, T) =
huffman@30132
    89
  Const(@{const_name Rep_CFun}, (S ->> T) --> (S --> T));
huffman@30132
    90
huffman@30132
    91
fun cabs_const (S, T) =
huffman@30132
    92
  Const(@{const_name Abs_CFun}, (S --> T) --> (S ->> T));
huffman@30132
    93
huffman@30132
    94
fun mk_capply (t, u) =
huffman@30132
    95
  let val (S, T) =
huffman@30132
    96
    case Term.fastype_of t of
huffman@30132
    97
        Type(@{type_name "->"}, [S, T]) => (S, T)
huffman@30132
    98
      | _ => raise TERM ("mk_capply " ^ ML_Syntax.print_list ML_Syntax.print_term [t, u], [t, u]);
huffman@30132
    99
  in capply_const (S, T) $ t $ u end;
huffman@30132
   100
huffman@30132
   101
infix 0 ==;  val (op ==) = Logic.mk_equals;
huffman@30132
   102
infix 1 ===; val (op ===) = HOLogic.mk_eq;
huffman@30132
   103
infix 9 `  ; val (op `) = mk_capply;
huffman@30132
   104
huffman@30132
   105
huffman@30132
   106
fun mk_cpair (t, u) =
huffman@30132
   107
  let val T = Term.fastype_of t
huffman@30132
   108
      val U = Term.fastype_of u
huffman@30132
   109
      val cpairT = T ->> U ->> HOLogic.mk_prodT (T, U)
huffman@30132
   110
  in Const(@{const_name cpair}, cpairT) ` t ` u end;
huffman@30132
   111
huffman@30132
   112
fun mk_cfst t =
huffman@30132
   113
  let val T = Term.fastype_of t;
huffman@30132
   114
      val (U, _) = HOLogic.dest_prodT T;
huffman@30132
   115
  in Const(@{const_name cfst}, T ->> U) ` t end;
huffman@30132
   116
huffman@30132
   117
fun mk_csnd t =
huffman@30132
   118
  let val T = Term.fastype_of t;
huffman@30132
   119
      val (_, U) = HOLogic.dest_prodT T;
huffman@30132
   120
  in Const(@{const_name csnd}, T ->> U) ` t end;
huffman@30132
   121
huffman@30132
   122
fun mk_csplit t =
huffman@30132
   123
  let val (S, TU) = dest_cfunT (Term.fastype_of t);
huffman@30132
   124
      val (T, U) = dest_cfunT TU;
huffman@30132
   125
      val csplitT = (S ->> T ->> U) ->> HOLogic.mk_prodT (S, T) ->> U;
huffman@30132
   126
  in Const(@{const_name csplit}, csplitT) ` t end;
wenzelm@23152
   127
wenzelm@23152
   128
(* builds the expression (LAM v. rhs) *)
huffman@30132
   129
fun big_lambda v rhs =
huffman@30132
   130
  cabs_const (Term.fastype_of v, Term.fastype_of rhs) $ Term.lambda v rhs;
wenzelm@23152
   131
wenzelm@23152
   132
(* builds the expression (LAM v1 v2 .. vn. rhs) *)
wenzelm@23152
   133
fun big_lambdas [] rhs = rhs
wenzelm@23152
   134
  | big_lambdas (v::vs) rhs = big_lambda v (big_lambdas vs rhs);
wenzelm@23152
   135
wenzelm@23152
   136
(* builds the expression (LAM <v1,v2,..,vn>. rhs) *)
huffman@30132
   137
fun lambda_ctuple [] rhs = big_lambda (Free("unit", HOLogic.unitT)) rhs
wenzelm@23152
   138
  | lambda_ctuple (v::[]) rhs = big_lambda v rhs
wenzelm@23152
   139
  | lambda_ctuple (v::vs) rhs =
huffman@30132
   140
      mk_csplit (big_lambda v (lambda_ctuple vs rhs));
wenzelm@23152
   141
wenzelm@23152
   142
(* builds the expression <v1,v2,..,vn> *)
huffman@30132
   143
fun mk_ctuple [] = @{term "UU::unit"}
wenzelm@23152
   144
|   mk_ctuple (t::[]) = t
huffman@30132
   145
|   mk_ctuple (t::ts) = mk_cpair (t, mk_ctuple ts);
huffman@30132
   146
huffman@30132
   147
fun mk_return t =
huffman@30132
   148
  let val T = Term.fastype_of t
huffman@30132
   149
  in Const(@{const_name Fixrec.return}, T ->> maybeT T) ` t end;
huffman@30132
   150
huffman@30132
   151
fun mk_bind (t, u) =
huffman@30132
   152
  let val (T, mU) = dest_cfunT (Term.fastype_of u);
huffman@30132
   153
      val bindT = maybeT T ->> (T ->> mU) ->> mU;
huffman@30132
   154
  in Const(@{const_name Fixrec.bind}, bindT) ` t ` u end;
huffman@30132
   155
huffman@30132
   156
fun mk_mplus (t, u) =
huffman@30132
   157
  let val mT = Term.fastype_of t
huffman@30132
   158
  in Const(@{const_name Fixrec.mplus}, mT ->> mT ->> mT) ` t ` u end;
huffman@30132
   159
huffman@30132
   160
fun mk_run t =
huffman@30132
   161
  let val mT = Term.fastype_of t
huffman@30132
   162
      val T = dest_maybeT mT
huffman@30132
   163
  in Const(@{const_name Fixrec.run}, mT ->> T) ` t end;
huffman@30132
   164
huffman@30132
   165
fun mk_fix t =
huffman@30132
   166
  let val (T, _) = dest_cfunT (Term.fastype_of t)
huffman@30132
   167
  in Const(@{const_name fix}, (T ->> T) ->> T) ` t end;
wenzelm@23152
   168
wenzelm@23152
   169
(*************************************************************************)
wenzelm@23152
   170
(************* fixed-point definitions and unfolding theorems ************)
wenzelm@23152
   171
(*************************************************************************)
wenzelm@23152
   172
huffman@30158
   173
fun add_fixdefs
huffman@30158
   174
  (fixes : ((binding * typ) * mixfix) list)
huffman@30158
   175
  (spec : (Attrib.binding * term) list)
huffman@30158
   176
  (lthy : local_theory) =
wenzelm@23152
   177
  let
wenzelm@30223
   178
    val names = map (Binding.name_of o fst o fst) fixes;
huffman@30158
   179
    val all_names = space_implode "_" names;
huffman@30158
   180
    val (lhss,rhss) = ListPair.unzip (map (dest_eqs o snd) spec);
huffman@30132
   181
    val fixpoint = mk_fix (lambda_ctuple lhss (mk_ctuple rhss));
wenzelm@23152
   182
    
huffman@30158
   183
    fun one_def (l as Free(n,_)) r =
huffman@30158
   184
          let val b = Sign.base_name n
huffman@30158
   185
          in ((Binding.name (b^"_def"), []), r) end
wenzelm@23152
   186
      | one_def _ _ = fixrec_err "fixdefs: lhs not of correct form";
wenzelm@23152
   187
    fun defs [] _ = []
wenzelm@23152
   188
      | defs (l::[]) r = [one_def l r]
huffman@30132
   189
      | defs (l::ls) r = one_def l (mk_cfst r) :: defs ls (mk_csnd r);
huffman@30158
   190
    val fixdefs = defs lhss fixpoint;
huffman@30158
   191
    val define_all = fold_map (LocalTheory.define Thm.definitionK);
huffman@30158
   192
    val (fixdef_thms : (term * (string * thm)) list, lthy') = lthy
huffman@30158
   193
      |> define_all (map (apfst fst) fixes ~~ fixdefs);
huffman@30158
   194
    fun cpair_equalI (thm1, thm2) = @{thm cpair_equalI} OF [thm1, thm2];
huffman@30158
   195
    val ctuple_fixdef_thm = foldr1 cpair_equalI (map (snd o snd) fixdef_thms);
huffman@30158
   196
    val ctuple_induct_thm = ctuple_fixdef_thm RS def_fix_ind;
huffman@30158
   197
    val ctuple_unfold_thm =
huffman@30158
   198
      Goal.prove lthy' [] [] (mk_trp (mk_ctuple lhss === mk_ctuple rhss))
huffman@30158
   199
        (fn _ => EVERY [rtac (ctuple_fixdef_thm RS fix_eq2 RS trans) 1,
huffman@30158
   200
                   simp_tac (local_simpset_of lthy') 1]);
wenzelm@23152
   201
    fun unfolds [] thm = []
wenzelm@23152
   202
      | unfolds (n::[]) thm = [(n^"_unfold", thm)]
wenzelm@23152
   203
      | unfolds (n::ns) thm = let
wenzelm@25132
   204
          val thmL = thm RS @{thm cpair_eqD1};
wenzelm@25132
   205
          val thmR = thm RS @{thm cpair_eqD2};
wenzelm@23152
   206
        in (n^"_unfold", thmL) :: unfolds ns thmR end;
wenzelm@23152
   207
    val unfold_thms = unfolds names ctuple_unfold_thm;
huffman@30158
   208
    fun mk_note (n, thm) = ((Binding.name n, []), [thm]);
huffman@30158
   209
    val (thmss, lthy'') = lthy'
huffman@30158
   210
      |> fold_map (LocalTheory.note Thm.theoremK o mk_note)
huffman@30158
   211
        ((all_names ^ "_induct", ctuple_induct_thm) :: unfold_thms);
wenzelm@23152
   212
  in
huffman@30158
   213
    (lthy'', names, fixdef_thms, map snd unfold_thms)
wenzelm@23152
   214
  end;
wenzelm@23152
   215
wenzelm@23152
   216
(*************************************************************************)
wenzelm@23152
   217
(*********** monadic notation and pattern matching compilation ***********)
wenzelm@23152
   218
(*************************************************************************)
wenzelm@23152
   219
huffman@30131
   220
structure FixrecMatchData = TheoryDataFun (
huffman@30131
   221
  type T = string Symtab.table;
huffman@30131
   222
  val empty = Symtab.empty;
huffman@30131
   223
  val copy = I;
huffman@30131
   224
  val extend = I;
huffman@30131
   225
  fun merge _ tabs : T = Symtab.merge (K true) tabs;
huffman@30131
   226
);
huffman@30131
   227
huffman@30131
   228
(* associate match functions with pattern constants *)
huffman@30131
   229
fun add_matchers ms = FixrecMatchData.map (fold Symtab.update ms);
huffman@30131
   230
huffman@30157
   231
fun taken_names (t : term) : bstring list =
huffman@30157
   232
  let
huffman@30157
   233
    fun taken (Const(a,_), bs) = insert (op =) (Sign.base_name a) bs
huffman@30157
   234
      | taken (Free(a,_) , bs) = insert (op =) a bs
huffman@30157
   235
      | taken (f $ u     , bs) = taken (f, taken (u, bs))
huffman@30157
   236
      | taken (Abs(a,_,t), bs) = taken (t, insert (op =) a bs)
huffman@30157
   237
      | taken (_         , bs) = bs;
huffman@30157
   238
  in
huffman@30157
   239
    taken (t, [])
huffman@30157
   240
  end;
wenzelm@23152
   241
wenzelm@23152
   242
(* builds a monadic term for matching a constructor pattern *)
huffman@30131
   243
fun pre_build match_name pat rhs vs taken =
wenzelm@23152
   244
  case pat of
huffman@26045
   245
    Const(@{const_name Rep_CFun},_)$f$(v as Free(n,T)) =>
huffman@30131
   246
      pre_build match_name f rhs (v::vs) taken
huffman@26045
   247
  | Const(@{const_name Rep_CFun},_)$f$x =>
huffman@30131
   248
      let val (rhs', v, taken') = pre_build match_name x rhs [] taken;
huffman@30131
   249
      in pre_build match_name f rhs' (v::vs) taken' end
wenzelm@23152
   250
  | Const(c,T) =>
wenzelm@23152
   251
      let
wenzelm@23152
   252
        val n = Name.variant taken "v";
huffman@26045
   253
        fun result_type (Type(@{type_name "->"},[_,T])) (x::xs) = result_type T xs
wenzelm@23152
   254
          | result_type T _ = T;
wenzelm@23152
   255
        val v = Free(n, result_type T vs);
huffman@30132
   256
        val m = Const(match_name c, matchT T);
wenzelm@23152
   257
        val k = lambda_ctuple vs rhs;
wenzelm@23152
   258
      in
huffman@30132
   259
        (mk_bind (m`v, k), v, n::taken)
wenzelm@23152
   260
      end
wenzelm@23152
   261
  | Free(n,_) => fixrec_err ("expected constructor, found free variable " ^ quote n)
wenzelm@23152
   262
  | _ => fixrec_err "pre_build: invalid pattern";
wenzelm@23152
   263
wenzelm@23152
   264
(* builds a monadic term for matching a function definition pattern *)
wenzelm@23152
   265
(* returns (name, arity, matcher) *)
huffman@30131
   266
fun building match_name pat rhs vs taken =
wenzelm@23152
   267
  case pat of
huffman@26045
   268
    Const(@{const_name Rep_CFun}, _)$f$(v as Free(n,T)) =>
huffman@30131
   269
      building match_name f rhs (v::vs) taken
huffman@26045
   270
  | Const(@{const_name Rep_CFun}, _)$f$x =>
huffman@30131
   271
      let val (rhs', v, taken') = pre_build match_name x rhs [] taken;
huffman@30131
   272
      in building match_name f rhs' (v::vs) taken' end
huffman@30158
   273
  | Free(_,_) => ((pat, length vs), big_lambdas vs rhs)
huffman@30158
   274
  | Const(_,_) => ((pat, length vs), big_lambdas vs rhs)
huffman@30158
   275
  | _ => fixrec_err ("function is not declared as constant in theory: "
huffman@30158
   276
                    ^ ML_Syntax.print_term pat);
wenzelm@23152
   277
huffman@30158
   278
fun strip_alls t =
huffman@30158
   279
  if Logic.is_all t then strip_alls (snd (Logic.dest_all t)) else t;
huffman@30158
   280
huffman@30158
   281
fun match_eq match_name eq =
huffman@30158
   282
  let
huffman@30158
   283
    val (lhs,rhs) = dest_eqs (Logic.strip_imp_concl (strip_alls eq));
huffman@30131
   284
  in
huffman@30157
   285
    building match_name lhs (mk_return rhs) [] (taken_names eq)
huffman@30131
   286
  end;
wenzelm@23152
   287
wenzelm@23152
   288
(* returns the sum (using +++) of the terms in ms *)
wenzelm@23152
   289
(* also applies "run" to the result! *)
wenzelm@23152
   290
fun fatbar arity ms =
wenzelm@23152
   291
  let
huffman@30132
   292
    fun LAM_Ts 0 t = ([], Term.fastype_of t)
huffman@30132
   293
      | LAM_Ts n (_ $ Abs(_,T,t)) =
huffman@30132
   294
          let val (Ts, U) = LAM_Ts (n-1) t in (T::Ts, U) end
huffman@30132
   295
      | LAM_Ts _ _ = fixrec_err "fatbar: internal error, not enough LAMs";
wenzelm@23152
   296
    fun unLAM 0 t = t
wenzelm@23152
   297
      | unLAM n (_$Abs(_,_,t)) = unLAM (n-1) t
wenzelm@23152
   298
      | unLAM _ _ = fixrec_err "fatbar: internal error, not enough LAMs";
huffman@30132
   299
    fun reLAM ([], U) t = t
huffman@30132
   300
      | reLAM (T::Ts, U) t = reLAM (Ts, T ->> U) (cabs_const(T,U)$Abs("",T,t));
huffman@30132
   301
    val msum = foldr1 mk_mplus (map (unLAM arity) ms);
huffman@30132
   302
    val (Ts, U) = LAM_Ts arity (hd ms)
wenzelm@23152
   303
  in
huffman@30132
   304
    reLAM (rev Ts, dest_maybeT U) (mk_run msum)
wenzelm@23152
   305
  end;
wenzelm@23152
   306
wenzelm@23152
   307
(* this is the pattern-matching compiler function *)
huffman@30158
   308
fun compile_pats match_name eqs =
wenzelm@23152
   309
  let
huffman@30158
   310
    val (((n::names),(a::arities)),mats) =
huffman@30158
   311
      apfst ListPair.unzip (ListPair.unzip (map (match_eq match_name) eqs));
wenzelm@23152
   312
    val cname = if forall (fn x => n=x) names then n
wenzelm@23152
   313
          else fixrec_err "all equations in block must define the same function";
wenzelm@23152
   314
    val arity = if forall (fn x => a=x) arities then a
wenzelm@23152
   315
          else fixrec_err "all equations in block must have the same arity";
wenzelm@23152
   316
    val rhs = fatbar arity mats;
wenzelm@23152
   317
  in
huffman@30132
   318
    mk_trp (cname === rhs)
wenzelm@23152
   319
  end;
wenzelm@23152
   320
wenzelm@23152
   321
(*************************************************************************)
wenzelm@23152
   322
(********************** Proving associated theorems **********************)
wenzelm@23152
   323
(*************************************************************************)
wenzelm@23152
   324
wenzelm@23152
   325
(* proves a block of pattern matching equations as theorems, using unfold *)
huffman@30158
   326
fun make_simps lthy (unfold_thm, eqns : (Attrib.binding * term) list) =
wenzelm@23152
   327
  let
huffman@30158
   328
    val tacs =
huffman@30158
   329
      [rtac (unfold_thm RS @{thm ssubst_lhs}) 1,
huffman@30158
   330
       asm_simp_tac (local_simpset_of lthy) 1];
huffman@30158
   331
    fun prove_term t = Goal.prove lthy [] [] t (K (EVERY tacs));
huffman@30158
   332
    fun prove_eqn (bind, eqn_t) = (bind, prove_term eqn_t);
wenzelm@23152
   333
  in
wenzelm@23152
   334
    map prove_eqn eqns
wenzelm@23152
   335
  end;
wenzelm@23152
   336
wenzelm@23152
   337
(*************************************************************************)
wenzelm@23152
   338
(************************* Main fixrec function **************************)
wenzelm@23152
   339
(*************************************************************************)
wenzelm@23152
   340
huffman@30158
   341
local
huffman@30158
   342
(* code adapted from HOL/Tools/primrec_package.ML *)
huffman@30158
   343
huffman@30158
   344
fun prepare_spec prep_spec ctxt raw_fixes raw_spec =
huffman@30158
   345
  let
huffman@30158
   346
    val ((fixes, spec), _) = prep_spec
huffman@30158
   347
      raw_fixes (map (single o apsnd single) raw_spec) ctxt
huffman@30158
   348
  in (fixes, map (apsnd the_single) spec) end;
huffman@30158
   349
huffman@30158
   350
fun gen_fixrec
huffman@30158
   351
  (set_group : bool)
huffman@30158
   352
  (prep_spec : (binding * 'a option * mixfix) list ->
huffman@30158
   353
       (Attrib.binding * 'b list) list list ->
huffman@30158
   354
      Proof.context ->
huffman@30158
   355
   (((binding * typ) * mixfix) list * (Attrib.binding * term list) list)
huffman@30158
   356
    * Proof.context
huffman@30158
   357
  )
huffman@30158
   358
  (strict : bool)
huffman@30158
   359
  raw_fixes
huffman@30158
   360
  raw_spec
huffman@30158
   361
  (lthy : local_theory) =
wenzelm@23152
   362
  let
huffman@30158
   363
    val (fixes : ((binding * typ) * mixfix) list,
huffman@30158
   364
         spec : (Attrib.binding * term) list) =
huffman@30158
   365
          prepare_spec prep_spec lthy raw_fixes raw_spec;
huffman@30158
   366
    val chead_of_spec =
huffman@30158
   367
      chead_of o fst o dest_eqs o Logic.strip_imp_concl o strip_alls o snd;
huffman@30158
   368
    fun name_of (Free (n, _)) = n
huffman@30158
   369
      | name_of t = fixrec_err ("unknown term");
huffman@30158
   370
    val all_names = map (name_of o chead_of_spec) spec;
huffman@30158
   371
    val names = distinct (op =) all_names;
huffman@30158
   372
    fun block_of_name n =
huffman@30158
   373
      map_filter
huffman@30158
   374
        (fn (m,eq) => if m = n then SOME eq else NONE)
huffman@30158
   375
        (all_names ~~ spec);
huffman@30158
   376
    val blocks = map block_of_name names;
huffman@30158
   377
huffman@30158
   378
    val matcher_tab = FixrecMatchData.get (ProofContext.theory_of lthy);
huffman@30131
   379
    fun match_name c =
huffman@30158
   380
      case Symtab.lookup matcher_tab c of SOME m => m
huffman@30158
   381
        | NONE => fixrec_err ("unknown pattern constructor: " ^ c);
huffman@30131
   382
huffman@30158
   383
    val matches = map (compile_pats match_name) (map (map snd) blocks);
huffman@30158
   384
    val spec' = map (pair Attrib.empty_binding) matches;
huffman@30158
   385
    val (lthy', cnames, fixdef_thms, unfold_thms) =
huffman@30158
   386
      add_fixdefs fixes spec' lthy;
wenzelm@23152
   387
  in
wenzelm@23152
   388
    if strict then let (* only prove simp rules if strict = true *)
huffman@30158
   389
      val simps : (Attrib.binding * thm) list list =
huffman@30158
   390
        map (make_simps lthy') (unfold_thms ~~ blocks);
huffman@30158
   391
      fun mk_bind n : Attrib.binding =
huffman@30158
   392
       (Binding.name (n ^ "_simps"),
huffman@30158
   393
         [Attrib.internal (K Simplifier.simp_add)]);
huffman@30158
   394
      val simps1 : (Attrib.binding * thm list) list =
huffman@30158
   395
        map (fn (n,xs) => (mk_bind n, map snd xs)) (names ~~ simps);
huffman@30158
   396
      val simps2 : (Attrib.binding * thm list) list =
huffman@30158
   397
        map (apsnd (fn thm => [thm])) (List.concat simps);
huffman@30158
   398
      val (_, lthy'') = lthy'
huffman@30158
   399
        |> fold_map (LocalTheory.note Thm.theoremK) (simps1 @ simps2);
wenzelm@23152
   400
    in
huffman@30158
   401
      lthy''
wenzelm@23152
   402
    end
huffman@30158
   403
    else lthy'
wenzelm@23152
   404
  end;
wenzelm@23152
   405
huffman@30158
   406
in
wenzelm@23152
   407
huffman@30158
   408
val add_fixrec_i = gen_fixrec false Specification.check_specification;
huffman@30158
   409
val add_fixrec = gen_fixrec true Specification.read_specification;
huffman@30158
   410
huffman@30158
   411
end; (* local *)
wenzelm@23152
   412
wenzelm@23152
   413
(*************************************************************************)
wenzelm@23152
   414
(******************************** Fixpat *********************************)
wenzelm@23152
   415
(*************************************************************************)
wenzelm@23152
   416
wenzelm@23152
   417
fun fix_pat thy t = 
wenzelm@23152
   418
  let
wenzelm@23152
   419
    val T = fastype_of t;
wenzelm@23152
   420
    val eq = mk_trp (HOLogic.eq_const T $ t $ Var (("x",0),T));
wenzelm@23152
   421
    val cname = case chead_of t of Const(c,_) => c | _ =>
wenzelm@23152
   422
              fixrec_err "function is not declared as constant in theory";
wenzelm@26343
   423
    val unfold_thm = PureThy.get_thm thy (cname^"_unfold");
wenzelm@23152
   424
    val simp = Goal.prove_global thy [] [] eq
wenzelm@23152
   425
          (fn _ => EVERY [stac unfold_thm 1, simp_tac (simpset_of thy) 1]);
wenzelm@23152
   426
  in simp end;
wenzelm@23152
   427
wenzelm@23152
   428
fun gen_add_fixpat prep_term prep_attrib ((name, srcs), strings) thy =
wenzelm@23152
   429
  let
wenzelm@23152
   430
    val atts = map (prep_attrib thy) srcs;
wenzelm@23152
   431
    val ts = map (prep_term thy) strings;
wenzelm@23152
   432
    val simps = map (fix_pat thy) ts;
wenzelm@23152
   433
  in
haftmann@29585
   434
    (snd o PureThy.add_thmss [((name, simps), atts)]) thy
wenzelm@23152
   435
  end;
wenzelm@23152
   436
wenzelm@24707
   437
val add_fixpat = gen_add_fixpat Syntax.read_term_global Attrib.attribute;
wenzelm@23152
   438
val add_fixpat_i = gen_add_fixpat Sign.cert_term (K I);
wenzelm@23152
   439
wenzelm@23152
   440
wenzelm@23152
   441
(*************************************************************************)
wenzelm@23152
   442
(******************************** Parsers ********************************)
wenzelm@23152
   443
(*************************************************************************)
wenzelm@23152
   444
wenzelm@23152
   445
local structure P = OuterParse and K = OuterKeyword in
wenzelm@23152
   446
huffman@30158
   447
(* bool parser *)
wenzelm@23152
   448
val fixrec_strict = P.opt_keyword "permissive" >> not;
wenzelm@23152
   449
huffman@30158
   450
fun pipe_error t = P.!!! (Scan.fail_with (K
huffman@30158
   451
  (cat_lines ["Equations must be separated by " ^ quote "|", quote t])));
huffman@30158
   452
huffman@30158
   453
(* (Attrib.binding * string) parser *)
huffman@30158
   454
val statement = SpecParse.opt_thm_name ":" -- P.prop --| Scan.ahead
huffman@30158
   455
  ((P.term :-- pipe_error) || Scan.succeed ("",""));
huffman@30158
   456
huffman@30158
   457
(* ((Attrib.binding * string) list) parser *)
huffman@30158
   458
val statements = P.enum1 "|" statement;
huffman@30158
   459
huffman@30158
   460
(* (((xstring option * bool) * (Binding.binding * string option * Mixfix.mixfix) list)
huffman@30158
   461
   * (Attrib.binding * string) list) parser *)
huffman@30158
   462
val fixrec_decl =
huffman@30158
   463
  P.opt_target -- fixrec_strict -- P.fixes --| P.$$$ "where" -- statements;
wenzelm@23152
   464
wenzelm@23152
   465
(* this builds a parser for a new keyword, fixrec, whose functionality 
wenzelm@23152
   466
is defined by add_fixrec *)
wenzelm@24867
   467
val _ =
huffman@30158
   468
  let
huffman@30158
   469
    val desc = "define recursive functions (HOLCF)";
huffman@30158
   470
    fun fixrec (((opt_target, strict), raw_fixes), raw_spec) =
huffman@30158
   471
      Toplevel.local_theory opt_target (add_fixrec strict raw_fixes raw_spec);
huffman@30158
   472
  in
huffman@30158
   473
    OuterSyntax.command "fixrec" desc K.thy_decl (fixrec_decl >> fixrec)
huffman@30158
   474
  end;
wenzelm@23152
   475
wenzelm@23152
   476
(* fixpat parser *)
wenzelm@23152
   477
val fixpat_decl = SpecParse.opt_thm_name ":" -- Scan.repeat1 P.prop;
wenzelm@23152
   478
wenzelm@24867
   479
val _ =
wenzelm@23152
   480
  OuterSyntax.command "fixpat" "define rewrites for fixrec functions" K.thy_decl
wenzelm@23152
   481
    (fixpat_decl >> (Toplevel.theory o add_fixpat));
huffman@30158
   482
  
huffman@26045
   483
end; (* local structure *)
wenzelm@23152
   484
huffman@30131
   485
val setup = FixrecMatchData.init;
huffman@30131
   486
wenzelm@24867
   487
end;