diff -r f550c4cf3f3a -r 8448ba49d681 src/Pure/Isar/code_unit.ML
--- a/src/Pure/Isar/code_unit.ML	Fri May 15 15:12:23 2009 -0700
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,447 +0,0 @@
-(*  Title:      Pure/Isar/code_unit.ML
-    Author:     Florian Haftmann, TU Muenchen
-
-Basic notions of code generation.  Auxiliary.
-*)
-
-signature CODE_UNIT =
-sig
-  (*typ instantiations*)
-  val typscheme: theory -> string * typ -> (string * sort) list * typ
-  val inst_thm: theory -> sort Vartab.table -> thm -> thm
-  val constrain_thm: theory -> sort -> thm -> thm
-
-  (*constant aliasses*)
-  val add_const_alias: thm -> theory -> theory
-  val triv_classes: theory -> class list
-  val resubst_alias: theory -> string -> string
-
-  (*constants*)
-  val string_of_typ: theory -> typ -> string
-  val string_of_const: theory -> string -> string
-  val no_args: theory -> string -> int
-  val check_const: theory -> term -> string
-  val read_bare_const: theory -> string -> string * typ
-  val read_const: theory -> string -> string
-
-  (*constructor sets*)
-  val constrset_of_consts: theory -> (string * typ) list
-    -> string * ((string * sort) list * (string * typ list) list)
-
-  (*code equations*)
-  val mk_eqn: theory -> (string -> bool) -> thm * bool -> thm * bool
-  val mk_eqn_liberal: theory -> (string -> bool) -> thm -> (thm * bool) option
-  val assert_eqn: theory -> (string -> bool) -> thm * bool -> thm * bool
-  val const_eqn: theory -> thm -> string
-    val const_typ_eqn: thm -> string * typ
-  val typscheme_eqn: theory -> thm -> (string * sort) list * typ
-  val expand_eta: theory -> int -> thm -> thm
-  val rewrite_eqn: simpset -> thm -> thm
-  val rewrite_head: thm list -> thm -> thm
-  val norm_args: theory -> thm list -> thm list 
-  val norm_varnames: theory -> thm list -> thm list
-
-  (*case certificates*)
-  val case_cert: thm -> string * (int * string list)
-end;
-
-structure Code_Unit: CODE_UNIT =
-struct
-
-
-(* auxiliary *)
-
-fun string_of_typ thy = setmp show_sorts true (Syntax.string_of_typ_global thy);
-fun string_of_const thy c = case AxClass.inst_of_param thy c
- of SOME (c, tyco) => Sign.extern_const thy c ^ " " ^ enclose "[" "]" (Sign.extern_type thy tyco)
-  | NONE => Sign.extern_const thy c;
-
-fun no_args thy = length o fst o strip_type o Sign.the_const_type thy;
-
-
-(* utilities *)
-
-fun typscheme thy (c, ty) =
-  let
-    val ty' = Logic.unvarifyT ty;
-    fun dest (TFree (v, sort)) = (v, sort)
-      | dest ty = error ("Illegal type parameter in type scheme: " ^ Syntax.string_of_typ_global thy ty);
-    val vs = map dest (Sign.const_typargs thy (c, ty'));
-  in (vs, Type.strip_sorts ty') end;
-
-fun inst_thm thy tvars' thm =
-  let
-    val tvars = (Term.add_tvars o Thm.prop_of) thm [];
-    val inter_sort = Sorts.inter_sort (Sign.classes_of thy);
-    fun mk_inst (tvar as (v, sort)) = case Vartab.lookup tvars' v
-     of SOME sort' => SOME (pairself (Thm.ctyp_of thy o TVar)
-          (tvar, (v, inter_sort (sort, sort'))))
-      | NONE => NONE;
-    val insts = map_filter mk_inst tvars;
-  in Thm.instantiate (insts, []) thm end;
-
-fun constrain_thm thy sort thm =
-  let
-    val constrain = curry (Sorts.inter_sort (Sign.classes_of thy)) sort
-    val tvars = (Term.add_tvars o Thm.prop_of) thm [];
-    fun mk_inst (tvar as (v, sort)) = pairself (Thm.ctyp_of thy o TVar o pair v)
-      (sort, constrain sort)
-    val insts = map mk_inst tvars;
-  in Thm.instantiate (insts, []) thm end;
-
-fun expand_eta thy k thm =
-  let
-    val (lhs, rhs) = (Logic.dest_equals o Thm.plain_prop_of) thm;
-    val (head, args) = strip_comb lhs;
-    val l = if k = ~1
-      then (length o fst o strip_abs) rhs
-      else Int.max (0, k - length args);
-    val used = Name.make_context (map (fst o fst) (Term.add_vars lhs []));
-    fun get_name _ 0 = pair []
-      | get_name (Abs (v, ty, t)) k =
-          Name.variants [v]
-          ##>> get_name t (k - 1)
-          #>> (fn ([v'], vs') => (v', ty) :: vs')
-      | get_name t k = 
-          let
-            val (tys, _) = (strip_type o fastype_of) t
-          in case tys
-           of [] => raise TERM ("expand_eta", [t])
-            | ty :: _ =>
-                Name.variants [""]
-                #-> (fn [v] => get_name (t $ Var ((v, 0), ty)) (k - 1)
-                #>> (fn vs' => (v, ty) :: vs'))
-          end;
-    val (vs, _) = get_name rhs l used;
-    fun expand (v, ty) thm = Drule.fun_cong_rule thm
-      (Thm.cterm_of thy (Var ((v, 0), ty)));
-  in
-    thm
-    |> fold expand vs
-    |> Conv.fconv_rule Drule.beta_eta_conversion
-  end;
-
-fun eqn_conv conv =
-  let
-    fun lhs_conv ct = if can Thm.dest_comb ct
-      then (Conv.combination_conv lhs_conv conv) ct
-      else Conv.all_conv ct;
-  in Conv.combination_conv (Conv.arg_conv lhs_conv) conv end;
-
-fun head_conv conv =
-  let
-    fun lhs_conv ct = if can Thm.dest_comb ct
-      then (Conv.fun_conv lhs_conv) ct
-      else conv ct;
-  in Conv.fun_conv (Conv.arg_conv lhs_conv) end;
-
-val rewrite_eqn = Conv.fconv_rule o eqn_conv o Simplifier.rewrite;
-val rewrite_head = Conv.fconv_rule o head_conv o MetaSimplifier.rewrite false;
-
-fun norm_args thy thms =
-  let
-    val num_args_of = length o snd o strip_comb o fst o Logic.dest_equals;
-    val k = fold (curry Int.max o num_args_of o Thm.prop_of) thms 0;
-  in
-    thms
-    |> map (expand_eta thy k)
-    |> map (Conv.fconv_rule Drule.beta_eta_conversion)
-  end;
-
-fun canonical_tvars thy thm =
-  let
-    val ctyp = Thm.ctyp_of thy;
-    val purify_tvar = unprefix "'" #> Name.desymbolize false #> prefix "'";
-    fun tvars_subst_for thm = (fold_types o fold_atyps)
-      (fn TVar (v_i as (v, _), sort) => let
-            val v' = purify_tvar v
-          in if v = v' then I
-          else insert (op =) (v_i, (v', sort)) end
-        | _ => I) (prop_of thm) [];
-    fun mk_inst (v_i, (v', sort)) (maxidx, acc) =
-      let
-        val ty = TVar (v_i, sort)
-      in
-        (maxidx + 1, (ctyp ty, ctyp (TVar ((v', maxidx), sort))) :: acc)
-      end;
-    val maxidx = Thm.maxidx_of thm + 1;
-    val (_, inst) = fold mk_inst (tvars_subst_for thm) (maxidx + 1, []);
-  in Thm.instantiate (inst, []) thm end;
-
-fun canonical_vars thy thm =
-  let
-    val cterm = Thm.cterm_of thy;
-    val purify_var = Name.desymbolize false;
-    fun vars_subst_for thm = fold_aterms
-      (fn Var (v_i as (v, _), ty) => let
-            val v' = purify_var v
-          in if v = v' then I
-          else insert (op =) (v_i, (v', ty)) end
-        | _ => I) (prop_of thm) [];
-    fun mk_inst (v_i as (v, i), (v', ty)) (maxidx, acc) =
-      let
-        val t = Var (v_i, ty)
-      in
-        (maxidx + 1, (cterm t, cterm (Var ((v', maxidx), ty))) :: acc)
-      end;
-    val maxidx = Thm.maxidx_of thm + 1;
-    val (_, inst) = fold mk_inst (vars_subst_for thm) (maxidx + 1, []);
-  in Thm.instantiate ([], inst) thm end;
-
-fun canonical_absvars thm =
-  let
-    val t = Thm.plain_prop_of thm;
-    val purify_var = Name.desymbolize false;
-    val t' = Term.map_abs_vars purify_var t;
-  in Thm.rename_boundvars t t' thm end;
-
-fun norm_varnames thy thms =
-  let
-    fun burrow_thms f [] = []
-      | burrow_thms f thms =
-          thms
-          |> Conjunction.intr_balanced
-          |> f
-          |> Conjunction.elim_balanced (length thms)
-  in
-    thms
-    |> map (canonical_vars thy)
-    |> map canonical_absvars
-    |> map Drule.zero_var_indexes
-    |> burrow_thms (canonical_tvars thy)
-    |> Drule.zero_var_indexes_list
-  end;
-
-
-(* const aliasses *)
-
-structure ConstAlias = TheoryDataFun
-(
-  type T = ((string * string) * thm) list * class list;
-  val empty = ([], []);
-  val copy = I;
-  val extend = I;
-  fun merge _ ((alias1, classes1), (alias2, classes2)) : T =
-    (Library.merge (eq_snd Thm.eq_thm_prop) (alias1, alias2),
-      Library.merge (op =) (classes1, classes2));
-);
-
-fun add_const_alias thm thy =
-  let
-    val lhs_rhs = case try Logic.dest_equals (Thm.prop_of thm)
-     of SOME lhs_rhs => lhs_rhs
-      | _ => error ("Not an equation: " ^ Display.string_of_thm thm);
-    val c_c' = case try (pairself (AxClass.unoverload_const thy o dest_Const)) lhs_rhs
-     of SOME c_c' => c_c'
-      | _ => error ("Not an equation with two constants: " ^ Display.string_of_thm thm);
-    val some_class = the_list (AxClass.class_of_param thy (snd c_c'));
-  in thy |>
-    ConstAlias.map (fn (alias, classes) =>
-      ((c_c', thm) :: alias, fold (insert (op =)) some_class classes))
-  end;
-
-fun resubst_alias thy =
-  let
-    val alias = fst (ConstAlias.get thy);
-    val subst_inst_param = Option.map fst o AxClass.inst_of_param thy;
-    fun subst_alias c =
-      get_first (fn ((c', c''), _) => if c = c'' then SOME c' else NONE) alias;
-  in
-    perhaps subst_inst_param
-    #> perhaps subst_alias
-  end;
-
-val triv_classes = snd o ConstAlias.get;
-
-
-(* reading constants as terms *)
-
-fun check_bare_const thy t = case try dest_Const t
- of SOME c_ty => c_ty
-  | NONE => error ("Not a constant: " ^ Syntax.string_of_term_global thy t);
-
-fun check_const thy = AxClass.unoverload_const thy o check_bare_const thy;
-
-fun read_bare_const thy = check_bare_const thy o Syntax.read_term_global thy;
-
-fun read_const thy = AxClass.unoverload_const thy o read_bare_const thy;
-
-
-(* constructor sets *)
-
-fun constrset_of_consts thy cs =
-  let
-    val _ = map (fn (c, _) => if (is_some o AxClass.class_of_param thy) c
-      then error ("Is a class parameter: " ^ string_of_const thy c) else ()) cs;
-    fun no_constr (c, ty) = error ("Not a datatype constructor: " ^ string_of_const thy c
-      ^ " :: " ^ string_of_typ thy ty);
-    fun last_typ c_ty ty =
-      let
-        val frees = OldTerm.typ_tfrees ty;
-        val (tyco, vs) = ((apsnd o map) (dest_TFree) o dest_Type o snd o strip_type) ty
-          handle TYPE _ => no_constr c_ty
-        val _ = if has_duplicates (eq_fst (op =)) vs then no_constr c_ty else ();
-        val _ = if length frees <> length vs then no_constr c_ty else ();
-      in (tyco, vs) end;
-    fun ty_sorts (c, ty) =
-      let
-        val ty_decl = (Logic.unvarifyT o Sign.the_const_type thy) c;
-        val (tyco, _) = last_typ (c, ty) ty_decl;
-        val (_, vs) = last_typ (c, ty) ty;
-      in ((tyco, map snd vs), (c, (map fst vs, ty))) end;
-    fun add ((tyco', sorts'), c) ((tyco, sorts), cs) =
-      let
-        val _ = if tyco' <> tyco
-          then error "Different type constructors in constructor set"
-          else ();
-        val sorts'' = map2 (curry (Sorts.inter_sort (Sign.classes_of thy))) sorts' sorts
-      in ((tyco, sorts), c :: cs) end;
-    fun inst vs' (c, (vs, ty)) =
-      let
-        val the_v = the o AList.lookup (op =) (vs ~~ vs');
-        val ty' = map_atyps (fn TFree (v, _) => TFree (the_v v)) ty;
-      in (c, (fst o strip_type) ty') end;
-    val c' :: cs' = map ty_sorts cs;
-    val ((tyco, sorts), cs'') = fold add cs' (apsnd single c');
-    val vs = Name.names Name.context Name.aT sorts;
-    val cs''' = map (inst vs) cs'';
-  in (tyco, (vs, rev cs''')) end;
-
-
-(* code equations *)
-
-exception BAD_THM of string;
-fun bad_thm msg = raise BAD_THM msg;
-fun error_thm f thm = f thm handle BAD_THM msg => error msg;
-fun try_thm f thm = SOME (f thm) handle BAD_THM _ => NONE;
-
-fun is_linear thm =
-  let val (_, args) = (strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of) thm
-  in not (has_duplicates (op =) ((fold o fold_aterms)
-    (fn Var (v, _) => cons v | _ => I) args [])) end;
-
-fun gen_assert_eqn thy is_constr_head is_constr_pat (thm, proper) =
-  let
-    val (lhs, rhs) = (Logic.dest_equals o Thm.plain_prop_of) thm
-      handle TERM _ => bad_thm ("Not an equation: " ^ Display.string_of_thm thm)
-           | THM _ => bad_thm ("Not an equation: " ^ Display.string_of_thm thm);
-    fun vars_of t = fold_aterms (fn Var (v, _) => insert (op =) v
-      | Free _ => bad_thm ("Illegal free variable in equation\n"
-          ^ Display.string_of_thm thm)
-      | _ => I) t [];
-    fun tvars_of t = fold_term_types (fn _ =>
-      fold_atyps (fn TVar (v, _) => insert (op =) v
-        | TFree _ => bad_thm 
-      ("Illegal free type variable in equation\n" ^ Display.string_of_thm thm))) t [];
-    val lhs_vs = vars_of lhs;
-    val rhs_vs = vars_of rhs;
-    val lhs_tvs = tvars_of lhs;
-    val rhs_tvs = tvars_of rhs;
-    val _ = if null (subtract (op =) lhs_vs rhs_vs)
-      then ()
-      else bad_thm ("Free variables on right hand side of equation\n"
-        ^ Display.string_of_thm thm);
-    val _ = if null (subtract (op =) lhs_tvs rhs_tvs)
-      then ()
-      else bad_thm ("Free type variables on right hand side of equation\n"
-        ^ Display.string_of_thm thm)    val (head, args) = (strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of) thm;
-    val (c, ty) = case head
-     of Const (c_ty as (_, ty)) => (AxClass.unoverload_const thy c_ty, ty)
-      | _ => bad_thm ("Equation not headed by constant\n" ^ Display.string_of_thm thm);
-    fun check _ (Abs _) = bad_thm
-          ("Abstraction on left hand side of equation\n"
-            ^ Display.string_of_thm thm)
-      | check 0 (Var _) = ()
-      | check _ (Var _) = bad_thm
-          ("Variable with application on left hand side of equation\n"
-            ^ Display.string_of_thm thm)
-      | check n (t1 $ t2) = (check (n+1) t1; check 0 t2)
-      | check n (Const (c_ty as (c, ty))) = if n = (length o fst o strip_type) ty
-          then if not proper orelse is_constr_pat (AxClass.unoverload_const thy c_ty)
-            then ()
-            else bad_thm (quote c ^ " is not a constructor, on left hand side of equation\n"
-              ^ Display.string_of_thm thm)
-          else bad_thm
-            ("Partially applied constant " ^ quote c ^ " on left hand side of equation\n"
-               ^ Display.string_of_thm thm);
-    val _ = map (check 0) args;
-    val _ = if not proper orelse is_linear thm then ()
-      else bad_thm ("Duplicate variables on left hand side of equation\n"
-        ^ Display.string_of_thm thm);
-    val _ = if (is_none o AxClass.class_of_param thy) c
-      then ()
-      else bad_thm ("Polymorphic constant as head in equation\n"
-        ^ Display.string_of_thm thm)
-    val _ = if not (is_constr_head c)
-      then ()
-      else bad_thm ("Constructor as head in equation\n"
-        ^ Display.string_of_thm thm)
-    val ty_decl = Sign.the_const_type thy c;
-    val _ = if Sign.typ_equiv thy (Type.strip_sorts ty_decl, Type.strip_sorts ty)
-      then () else bad_thm ("Type\n" ^ string_of_typ thy ty
-           ^ "\nof equation\n"
-           ^ Display.string_of_thm thm
-           ^ "\nis incompatible with declared function type\n"
-           ^ string_of_typ thy ty_decl)
-  in (thm, proper) end;
-
-fun assert_eqn thy is_constr = error_thm (gen_assert_eqn thy is_constr is_constr);
-
-val const_typ_eqn = dest_Const o fst o strip_comb o fst o Logic.dest_equals o Thm.plain_prop_of;
-
-fun typscheme_eqn thy = typscheme thy o const_typ_eqn;
-
-(*these are permissive wrt. to overloaded constants!*)
-fun mk_eqn thy is_constr_head = error_thm (gen_assert_eqn thy is_constr_head (K true)) o
-  apfst (LocalDefs.meta_rewrite_rule (ProofContext.init thy));
-
-fun mk_eqn_liberal thy is_constr_head = Option.map (fn (thm, _) => (thm, is_linear thm))
-  o try_thm (gen_assert_eqn thy is_constr_head (K true))
-  o rpair false o LocalDefs.meta_rewrite_rule (ProofContext.init thy);
-
-fun const_eqn thy = AxClass.unoverload_const thy o const_typ_eqn;
-
-
-(* case cerificates *)
-
-fun case_certificate thm =
-  let
-    val ((head, raw_case_expr), cases) = (apfst Logic.dest_equals
-      o apsnd Logic.dest_conjunctions o Logic.dest_implies o Thm.prop_of) thm;
-    val _ = case head of Free _ => true
-      | Var _ => true
-      | _ => raise TERM ("case_cert", []);
-    val ([(case_var, _)], case_expr) = Term.strip_abs_eta 1 raw_case_expr;
-    val (Const (case_const, _), raw_params) = strip_comb case_expr;
-    val n = find_index (fn Free (v, _) => v = case_var | _ => false) raw_params;
-    val _ = if n = ~1 then raise TERM ("case_cert", []) else ();
-    val params = map (fst o dest_Var) (nth_drop n raw_params);
-    fun dest_case t =
-      let
-        val (head' $ t_co, rhs) = Logic.dest_equals t;
-        val _ = if head' = head then () else raise TERM ("case_cert", []);
-        val (Const (co, _), args) = strip_comb t_co;
-        val (Var (param, _), args') = strip_comb rhs;
-        val _ = if args' = args then () else raise TERM ("case_cert", []);
-      in (param, co) end;
-    fun analyze_cases cases =
-      let
-        val co_list = fold (AList.update (op =) o dest_case) cases [];
-      in map (the o AList.lookup (op =) co_list) params end;
-    fun analyze_let t =
-      let
-        val (head' $ arg, Var (param', _) $ arg') = Logic.dest_equals t;
-        val _ = if head' = head then () else raise TERM ("case_cert", []);
-        val _ = if arg' = arg then () else raise TERM ("case_cert", []);
-        val _ = if [param'] = params then () else raise TERM ("case_cert", []);
-      in [] end;
-    fun analyze (cases as [let_case]) =
-          (analyze_cases cases handle Bind => analyze_let let_case)
-      | analyze cases = analyze_cases cases;
-  in (case_const, (n, analyze cases)) end;
-
-fun case_cert thm = case_certificate thm
-  handle Bind => error "bad case certificate"
-       | TERM _ => error "bad case certificate";
-
-end;