added datatype category;

--- a/src/Pure/Isar/outer_keyword.ML	Tue Jul 01 21:30:08 2008 +0200
+++ b/src/Pure/Isar/outer_keyword.ML	Tue Jul 01 21:30:11 2008 +0200
@@ -47,6 +47,8 @@
   val report: unit -> unit
   val keyword: string -> unit
   val command: string -> T -> unit
+  datatype category = Theory | Proof | Other
+  val category_of: string -> category
 end;
 
 structure OuterKeyword: OUTER_KEYWORD =
@@ -89,6 +91,13 @@
   thy_goal, qed, qed_block, qed_global, prf_heading, prf_goal, prf_block, prf_open, prf_close,
   prf_chain, prf_decl, prf_asm, prf_asm_goal, prf_script] |> map kind_of;
 
+val thy_kinds =
+  [thy_begin, thy_switch, thy_end, thy_heading, thy_decl, thy_script, thy_goal] |> map kind_of;
+
+val prf_kinds =
+  [qed, qed_block, qed_global, prf_heading, prf_goal, prf_block, prf_open, prf_close,
+    prf_chain, prf_decl, prf_asm, prf_asm_goal, prf_script] |> map kind_of;
+
 
 (* tags *)
 
@@ -164,4 +173,19 @@
   change_commands (Symtab.update (name, kind));
   Pretty.writeln (report_command (name, kind)));
 
+
+(* overall category *)
+
+datatype category = Theory | Proof | Other;
+
+fun category_of name =
+  (case command_keyword name of
+    SOME kind =>
+      let val k = kind_of kind in
+        if member (op =) thy_kinds k then Theory
+        else if member (op =) prf_kinds k then Proof
+        else Other
+      end
+  | NONE => error ("Unknown command " ^ quote name));
+
 end;