Local theory operations, with optional target locale.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Pure/Isar/local_theory.ML	Sun Jan 22 18:46:01 2006 +0100
@@ -0,0 +1,83 @@
+(*  Title:      Pure/Isar/local_theory.ML
+    ID:         $Id$
+    Author:     Makarius
+
+Local theory operations, with optional target locale.
+*)
+
+signature LOCAL_THEORY =
+sig
+  val map_theory: (theory -> theory) -> Proof.context -> Proof.context
+  val map_theory_result: (theory -> 'a * theory) -> Proof.context -> 'a * Proof.context
+  val init: string option -> theory -> Proof.context
+  val exit: Proof.context -> theory
+  val params_of: Proof.context -> (string * typ) list
+  val consts: (string * typ * mixfix) list -> Proof.context ->
+    ((string * typ) list * term list) * Proof.context
+end;
+
+structure LocalTheory: LOCAL_THEORY =
+struct
+
+(* local context data *)
+
+structure Data = ProofDataFun
+(
+  val name = "Isar/local_theory";
+  type T =
+   {locale: string option,
+    params: (string * typ) list,
+    hyps: term list,
+    exit: theory -> theory};
+  fun init _ = {locale = NONE, params = [], hyps = [], exit = I};
+  fun print _ _ = ();
+);
+
+val _ = Context.add_setup Data.init;
+
+
+(* theory *)
+
+fun map_theory f ctxt =
+  ProofContext.transfer (f (ProofContext.theory_of ctxt)) ctxt;
+
+fun map_theory_result f ctxt =
+  let val (res, thy') = f (ProofContext.theory_of ctxt)
+  in (res, ProofContext.transfer thy' ctxt) end;
+
+fun init NONE thy = ProofContext.init thy
+  | init (SOME loc) thy =
+      thy
+      |> Locale.init loc
+      |> (fn ctxt => Data.put
+          {locale = SOME loc,
+           params = Locale.the_params thy loc,
+           hyps = ProofContext.assms_of ctxt,   (* FIXME query locale!! *)
+           exit = Sign.restore_naming thy} ctxt)
+      |> map_theory (Sign.add_path loc #> Sign.no_base_names);
+
+fun exit ctxt = #exit (Data.get ctxt) (ProofContext.theory_of ctxt);
+
+
+(* local theory *)
+
+val params_of = #params o Data.get;
+
+fun consts decls ctxt =
+  let
+    val thy = ProofContext.theory_of ctxt;
+    val params = params_of ctxt;
+    val ps = map Free params;
+    val Us = map snd params;
+
+    val xs = decls |> map (fn (c, _, mx) => Syntax.const_name c mx);
+    val Ts = map #2 decls;
+    fun const x T = Term.list_comb (Const (Sign.full_name thy x, Us ---> T), ps);
+  in
+    ctxt
+    |> map_theory (Sign.add_consts_i (decls |> map (fn (c, T, mx) => (c, Us ---> T, mx))))
+    |> ProofContext.add_fixes_i (decls |> map (fn (c, T, mx) => (c, SOME T, mx)))
+    |-> (fn xs' => pair ((xs' ~~ Ts), map2 const xs Ts))
+  end;
+
+end;