# HG changeset patch
# User wenzelm
# Date 1150565872 -7200
# Node ID 300bc6ce970d53095819cdddd0ae388575868551
# Parent  2b4a222fef3c758a706e5462a7f41dd0d5d8dffe
major reworking of export functionality -- based on Term/Thm.generalize;
tuned interfaces;

diff -r 2b4a222fef3c -r 300bc6ce970d src/Pure/variable.ML
--- a/src/Pure/variable.ML	Sat Jun 17 19:37:51 2006 +0200
+++ b/src/Pure/variable.ML	Sat Jun 17 19:37:52 2006 +0200
@@ -14,7 +14,7 @@
   val fixed_names_of: Context.proof -> string list
   val binds_of: Context.proof -> (typ * term) Vartab.table
   val defaults_of: Context.proof ->
-    typ Vartab.table * sort Vartab.table * string list * term list Symtab.table
+    typ Vartab.table * sort Vartab.table * string list * string list Symtab.table
   val used_types: Context.proof -> string list
   val is_declared: Context.proof -> string -> bool
   val is_fixed: Context.proof -> string -> bool
@@ -24,23 +24,29 @@
   val declare_type: typ -> Context.proof -> Context.proof
   val declare_syntax: term -> Context.proof -> Context.proof
   val declare_term: term -> Context.proof -> Context.proof
+  val rename_wrt: Context.proof -> term list -> (string * 'a) list -> (string * 'a) list
+  val add_fixes: string list -> Context.proof -> string list * Context.proof
+  val invent_fixes: string list -> Context.proof -> string list * Context.proof
   val invent_types: sort list -> Context.proof -> (string * sort) list * Context.proof
-  val rename_wrt: Context.proof -> term list -> (string * 'a) list -> (string * 'a) list
+  val export_inst: Context.proof -> Context.proof -> string list * string list
+  val exportT_inst: Context.proof -> Context.proof -> string list
+  val export_terms: Context.proof -> Context.proof -> term list -> term list
+  val exportT_terms: Context.proof -> Context.proof -> term list -> term list
+  val exportT: Context.proof -> Context.proof -> thm list -> thm list
+  val export: Context.proof -> Context.proof -> thm list -> thm list
+  val importT_inst: term list -> Context.proof -> ((indexname * sort) * typ) list * Context.proof
+  val import_inst: bool -> term list -> Context.proof ->
+    (((indexname * sort) * typ) list * ((indexname * typ) * term) list) * Context.proof
+  val importT_terms: term list -> Context.proof -> term list * Context.proof
+  val import_terms: bool -> term list -> Context.proof -> term list * Context.proof
+  val importT: thm list -> Context.proof -> thm list * Context.proof
+  val import: bool -> thm list -> Context.proof -> thm list * Context.proof
   val warn_extra_tfrees: Context.proof -> Context.proof -> unit
-  val generalize_tfrees: Context.proof -> Context.proof -> string list -> string list
-  val generalize: Context.proof -> Context.proof -> term list -> term list
+  val monomorphic: Context.proof -> term list -> term list
   val polymorphic: Context.proof -> term list -> term list
   val hidden_polymorphism: term -> typ -> (indexname * sort) list
-  val monomorphic_inst: term list -> Context.proof ->
-    ((indexname * sort) * typ) list * Context.proof
-  val monomorphic: Context.proof -> term list -> term list
   val add_binds: (indexname * term option) list -> Context.proof -> Context.proof
   val expand_binds: Context.proof -> term -> term
-  val add_fixes: string list -> Context.proof -> string list * Context.proof
-  val invent_fixes: string list -> Context.proof -> string list * Context.proof
-  val import_types: bool -> typ list -> Context.proof -> typ list * Context.proof
-  val import_terms: bool -> term list -> Context.proof -> term list * Context.proof
-  val import: bool -> thm list -> Context.proof -> thm list * Context.proof
 end;
 
 structure Variable: VARIABLE =
@@ -49,14 +55,14 @@
 (** local context data **)
 
 datatype data = Data of
- {is_body: bool,                          (*internal body mode*)
-  fixes: (string * string) list,          (*term fixes*)
+ {is_body: bool,                          (*inner body mode*)
+  fixes: (string * string) list,          (*term fixes -- extern/intern*)
   binds: (typ * term) Vartab.table,       (*term bindings*)
   defaults:
     typ Vartab.table *                    (*type constraints*)
     sort Vartab.table *                   (*default sorts*)
     string list *                         (*used type variables*)
-    term list Symtab.table};              (*type variable occurrences*)
+    string list Symtab.table};            (*occurrences of type variables in term variables*)
 
 fun make_data (is_body, fixes, binds, defaults) =
   Data {is_body = is_body, fixes = fixes, binds = binds, defaults = defaults};
@@ -141,7 +147,8 @@
   (fn TFree (x, _) => insert (op =) x | _ => I);
 
 val ins_occs = fold_term_types (fn t =>
-  fold_atyps (fn TFree (x, _) => Symtab.update_list (x, t) | _ => I));
+  let val x = case t of Free (x, _) => x | _ => ""
+  in fold_atyps (fn TFree (a, _) => Symtab.insert_list (op =) (a, x) | _ => I) end);
 
 fun ins_skolem def_ty = fold_rev (fn (x, x') =>
   (case def_ty x' of
@@ -162,6 +169,9 @@
   fold_types ins_used t used,
   occ));
 
+fun declare_occs t = map_defaults (fn (types, sorts, used, occ) =>
+  (types, sorts, used, ins_occs t occ));
+
 fun declare_term t ctxt =
   ctxt
   |> declare_syntax t
@@ -174,15 +184,6 @@
 end;
 
 
-(* invent types *)
-
-fun invent_types Ss ctxt =
-  let
-    val tfrees = Term.invent_names (used_types ctxt) "'a" (length Ss) ~~ Ss;
-    val ctxt' = fold (declare_type o TFree) tfrees ctxt;
-  in (tfrees, ctxt') end;
-
-
 (* renaming term/type frees *)
 
 fun rename_wrt ctxt ts frees =
@@ -198,24 +199,142 @@
 
 
 
-(** Hindley-Milner polymorphism **)
+(** fixes **)
+
+fun no_dups [] = ()
+  | no_dups dups = error ("Duplicate fixed variable(s): " ^ commas_quote dups);
+
+fun add_fixes xs ctxt =
+  let
+    val (ys, zs) = split_list (fixes_of ctxt);
+    val _ = no_dups (duplicates (op =) xs);
+    val _ =
+      (case filter (can Term.dest_skolem) xs of [] => ()
+      | bads => error ("Illegal internal Skolem constant(s): " ^ commas_quote bads));
+    val xs' =
+      if is_body ctxt then Term.variantlist (map Term.skolem xs, zs)
+      else (no_dups (xs inter_string ys); no_dups (xs inter_string zs); xs);
+  in
+    ctxt
+    |> map_fixes (fn fixes => rev (xs ~~ xs') @ fixes)
+    |> fold (declare_syntax o Syntax.free) xs'
+    |> pair xs'
+  end;
+
+fun invent_fixes xs ctxt =
+  ctxt
+  |> set_body true
+  |> add_fixes (Term.variantlist (xs, []))
+  ||> restore_body ctxt;
+
+fun invent_types Ss ctxt =
+  let
+    val tfrees = Term.invent_names (used_types ctxt) "'a" (length Ss) ~~ Ss;
+    val ctxt' = fold (declare_type o TFree) tfrees ctxt;
+  in (tfrees, ctxt') end;
+
+
+
+(** export -- generalize type/term variables **)
+
+fun export_inst inner outer =
+  let
+    val types_outer = used_types outer;
+    val fixes_inner = fixes_of inner;
+    val fixes_outer = fixes_of outer;
+
+    val gen_fixes = map #2 (Library.take (length fixes_inner - length fixes_outer, fixes_inner));
+    val still_fixed = not o member (op =) ("" :: gen_fixes);
+    val gen_fixesT =
+      Symtab.fold (fn (a, xs) =>
+        if member (op =) types_outer a orelse exists still_fixed xs
+        then I else cons a) (type_occs_of inner) [];
+  in (gen_fixesT, gen_fixes) end;
+
+fun exportT_inst inner outer = #1 (export_inst inner outer);
+
+fun exportT_terms inner outer ts =
+  map (Term.generalize (exportT_inst (fold declare_occs ts inner) outer, [])
+    (fold (Term.fold_types Term.maxidx_typ) ts ~1 + 1)) ts;
+
+fun export_terms inner outer ts =
+  map (Term.generalize (export_inst (fold declare_occs ts inner) outer)
+    (fold Term.maxidx_term ts ~1 + 1)) ts;
+
+fun gen_export inst inner outer ths =
+  let
+    val maxidx = fold Thm.maxidx_thm ths ~1;
+    val inner' = fold (declare_occs o Thm.full_prop_of) ths inner;
+  in map (Thm.generalize (inst inner' outer) (maxidx + 1)) ths end;
+
+val exportT = gen_export (rpair [] oo exportT_inst);
+val export = gen_export export_inst;
+
+
+
+(** import -- fix schematic type/term variables **)
+
+fun importT_inst ts ctxt =
+  let
+    val tvars = rev (fold Term.add_tvars ts []);
+    val (tfrees, ctxt') = invent_types (map #2 tvars) ctxt;
+  in (tvars ~~ map TFree tfrees, ctxt') end;
+
+fun import_inst is_open ts ctxt =
+  let
+    val (instT, ctxt') = importT_inst ts ctxt;
+    val vars = map (apsnd (Term.instantiateT instT)) (rev (fold Term.add_vars ts []));
+    val ren = if is_open then I else Term.internal;
+    val (xs, ctxt'') = invent_fixes (map (ren o #1 o #1) vars) ctxt';
+    val inst = vars ~~ map Free (xs ~~ map #2 vars);
+  in ((instT, inst), ctxt'') end;
+
+fun importT_terms ts ctxt =
+  let val (instT, ctxt') = importT_inst ts ctxt
+  in (map (Term.instantiate (instT, [])) ts, ctxt') end;
+
+fun import_terms is_open ts ctxt =
+  let val (inst, ctxt') = import_inst is_open ts ctxt
+  in (map (Term.instantiate inst) ts, ctxt') end;
+
+fun importT ths ctxt =
+  let
+    val thy = Context.theory_of_proof ctxt;
+    val certT = Thm.ctyp_of thy;
+    val (instT, ctxt') = importT_inst (map Thm.full_prop_of ths) ctxt;
+    val instT' = map (fn (v, T) => (certT (TVar v), certT T)) instT;
+    val ths' = map (Thm.instantiate (instT', [])) ths;
+  in (ths', ctxt') end;
+
+fun import is_open ths ctxt =
+  let
+    val thy = Context.theory_of_proof ctxt;
+    val cert = Thm.cterm_of thy;
+    val certT = Thm.ctyp_of thy;
+    val ((instT, inst), ctxt') = import_inst is_open (map Thm.full_prop_of ths) ctxt;
+    val instT' = map (fn (v, T) => (certT (TVar v), certT T)) instT;
+    val inst' = map (fn (v, t) => (cert (Var v), cert t)) inst;
+    val ths' = map (Thm.instantiate (instT', inst')) ths;
+  in (ths', ctxt') end;
+
+
+
+(** implicit polymorphism **)
 
 (* warn_extra_tfrees *)
 
 fun warn_extra_tfrees ctxt1 ctxt2 =
   let
-    fun occs_typ a (Type (_, Ts)) = exists (occs_typ a) Ts
-      | occs_typ a (TFree (b, _)) = a = b
-      | occs_typ _ (TVar _) = false;
-    fun occs_free a (Free (x, _)) =
+    fun occs_typ a = Term.exists_subtype (fn TFree (b, _) => a = b | _ => false);
+    fun occs_free _ "" = I
+      | occs_free a x =
           (case def_type ctxt1 false (x, ~1) of
             SOME T => if occs_typ a T then I else cons (a, x)
-          | NONE => cons (a, x))
-      | occs_free _ _ = I;
+          | NONE => cons (a, x));
 
     val occs1 = type_occs_of ctxt1 and occs2 = type_occs_of ctxt2;
-    val extras = Symtab.fold (fn (a, ts) =>
-      if Symtab.defined occs1 a then I else fold (occs_free a) ts) occs2 [];
+    val extras = Symtab.fold (fn (a, xs) =>
+      if Symtab.defined occs1 a then I else fold (occs_free a) xs) occs2 [];
     val tfrees = map #1 extras |> sort_distinct string_ord;
     val frees = map #2 extras |> sort_distinct string_ord;
   in
@@ -225,29 +344,16 @@
   end;
 
 
-(* generalize type variables *)
+(* monomorphic vs. polymorphic terms *)
 
-fun generalize_tfrees inner outer =
-  let
-    val extra_fixes = subtract (op =) (fixed_names_of outer) (fixed_names_of inner);
-    fun still_fixed (Free (x, _)) = not (member (op =) extra_fixes x)
-      | still_fixed _ = false;
-    val occs_inner = type_occs_of inner;
-    val occs_outer = type_occs_of outer;
-    fun add a gen =
-      if Symtab.defined occs_outer a orelse
-        exists still_fixed (Symtab.lookup_list occs_inner a)
-      then gen else a :: gen;
-  in fn tfrees => fold add tfrees [] end;
-
-fun generalize inner outer ts =
-  let
-    val tfrees = generalize_tfrees inner outer (map #1 (fold Term.add_tfrees ts []));
-    fun gen (x, S) = if member (op =) tfrees x then TVar ((x, 0), S) else TFree (x, S);
-  in map (Term.map_term_types (Term.map_type_tfree gen)) ts end;
+fun monomorphic ctxt ts =
+  #1 (importT_terms ts (fold declare_term ts ctxt));
 
 fun polymorphic ctxt ts =
-  generalize (fold declare_term ts ctxt) ctxt ts;
+  exportT_terms (fold declare_term ts ctxt) ctxt ts;
+
+
+(** term bindings **)
 
 fun hidden_polymorphism t T =
   let
@@ -256,22 +362,6 @@
       (fn TVar v => if member (op =) tvarsT v then I else insert (op =) v | _ => I)) t [];
   in extra_tvars end;
 
-
-(* monomorphic -- fixes type variables *)
-
-fun monomorphic_inst ts ctxt =
-  let
-    val tvars = rev (fold Term.add_tvars ts []);
-    val (tfrees, ctxt') = invent_types (map #2 tvars) ctxt;
-  in (tvars ~~ map TFree tfrees, ctxt') end;
-
-fun monomorphic ctxt ts =
-  map (Term.instantiate (#1 (monomorphic_inst ts (fold declare_term ts ctxt)), [])) ts;
-
-
-
-(** term abbreviations **)
-
 fun add_bind (xi, NONE) = map_binds (Vartab.delete_safe xi)
   | add_bind ((x, i), SOME t) =
       let
@@ -293,65 +383,4 @@
       | expand t = t;
   in Envir.beta_norm o Term.map_aterms expand end;
 
-
-
-(** fixes **)
-
-fun no_dups [] = ()
-  | no_dups dups = error ("Duplicate fixed variable(s): " ^ commas_quote dups);
-
-fun add_fixes xs ctxt =
-  let
-    val (ys, zs) = split_list (fixes_of ctxt);
-    val _ = no_dups (duplicates (op =) xs);
-    val _ =
-      (case filter (can Syntax.dest_skolem) xs of [] => ()
-      | bads => error ("Illegal internal Skolem constant(s): " ^ commas_quote bads));
-    val xs' =
-      if is_body ctxt then Term.variantlist (map Syntax.skolem xs, zs)
-      else (no_dups (xs inter_string ys); no_dups (xs inter_string zs); xs);
-  in
-    ctxt
-    |> map_fixes (fn fixes => rev (xs ~~ xs') @ fixes)
-    |> fold (declare_syntax o Syntax.free) xs'
-    |> pair xs'
-  end;
-
-fun invent_fixes xs ctxt =
-  ctxt
-  |> set_body true
-  |> add_fixes (Term.variantlist (xs, []))
-  ||> restore_body ctxt;
-
-
-(* import -- fixes schematic variables *)
-
-fun import_inst is_open ts ctxt =
-  let
-    val (instT, ctxt') = monomorphic_inst ts ctxt;
-    val vars = map (apsnd (Term.instantiateT instT)) (rev (fold Term.add_vars ts []));
-    val ren = if is_open then I else Syntax.internal;
-    val (xs, ctxt'') = invent_fixes (map (ren o #1 o #1) vars) ctxt';
-    val inst = vars ~~ map Free (xs ~~ map #2 vars);
-  in ((instT, inst), ctxt'') end;
-
-fun import_terms is_open ts ctxt =
-  let val (inst, ctxt') = import_inst is_open ts ctxt
-  in (map (Term.instantiate inst) ts, ctxt') end;
-
-fun import_types is_open Ts ctxt =
-  import_terms is_open (map Logic.mk_type Ts) ctxt
-  |>> map Logic.dest_type;
-
-fun import is_open ths ctxt =
-  let
-    val thy = Context.theory_of_proof ctxt;
-    val cert = Thm.cterm_of thy;
-    val certT = Thm.ctyp_of thy;
-    val ((instT, inst), ctxt') = import_inst is_open (map Thm.full_prop_of ths) ctxt;
-    val instT' = map (fn (v, T) => (certT (TVar v), certT T)) instT;
-    val inst' = map (fn (v, t) => (cert (Var v), cert t)) inst;
-    val ths' = map (Thm.instantiate (instT', inst')) ths;
-  in (ths', ctxt') end;
-
 end;