Merge lp:~mhr3/libzeitgeist/symbols into lp:libzeitgeist

[Michal Hruby]

First stab at a Symbol API, currently exposes only zeitgeist_symbol_is_a function, which can tell that a VECTOR_IMAGE is descendant of MEDIA etc. The C code is generated by the symboltree2c python script extracted from ZG ontology. I wonder if also other methods could be useful for libzg users?

[Mikkel Kamstrup Erlandsen (kamstrup)]

Nice! Some comments:

 1) I'd like to see a symbol_info_new() that takes ownership of the arguments since you introduce a lot of memory reallocation when building the symbol tree.

 2) Author in test-symbols.c is you, not me :-)

 3) I'd like to see get_children(), get_all_children(), and get_parents() as well. At least it is my experience that you quickly end up needing those once you start getting into it

 4) API documentation is needed for the public functions

 5) a VAPI update?

 6) Nice and thorough work on the unit tests!

review: Needs Fixing

[lp:~mhr3/libzeitgeist/symbols]

159. By Michal Hruby on 2010-08-09

Act upon review comments

[Michal Hruby (mhr3)]

Fixed 2) 3) 4) 5).

As for 1) I'm not inclined to make it take ownership, because it's taking GStrv, and therefore it'd suggest to free the data using g_strfreev(), but I pass static strings, so they don't need freeing. Also the SymbolInfo doesn't directly use the strings, it creates quarks from them.

[Mikkel Kamstrup Erlandsen (kamstrup)]

Ok, I'll accept your choice on 1). One last nitpick :-)

The namespace for the VAPI should be Zeitgeist.Symbol.* that way it's consistent with how we expose the Zeitgeist.Timestamp.* namespace as well as closer to the Python API for zeitgeist.datamodel.Symbol

review: Needs Fixing

[lp:~mhr3/libzeitgeist/symbols]

160. By Michal Hruby on 2010-08-09

Move the functions to Zeitgeist.Symbol namespace

161. By Michal Hruby on 2010-08-09

Add new header to zeitgeist.h

[Michal Hruby (mhr3)]

Moved to Zeitgeist.Symbol namespace. Should be good to go. ;)

[Mikkel Kamstrup Erlandsen (kamstrup)]

Cool. Nice work!

review: Approve

=== modified file 'bindings/zeitgeist-1.0-custom.vala'
--- bindings/zeitgeist-1.0-custom.vala	2010-06-23 09:43:18 +0000
+++ bindings/zeitgeist-1.0-custom.vala	2010-08-09 22:06:44 +0000
@@ -32,6 +32,18 @@
   }
 }
 
+namespace Zeitgeist.Symbol
+{
+  [CCode (cheader_filename = "zeitgeist.h")]
+  public static GLib.List<weak string> get_all_children (string symbol);
+  [CCode (cheader_filename = "zeitgeist.h")]
+  public static GLib.List<weak string> get_children (string symbol);
+  [CCode (cheader_filename = "zeitgeist.h")]
+  public static GLib.List<weak string> get_parents (string symbol);
+  [CCode (cheader_filename = "zeitgeist.h")]
+  public static bool is_a (string symbol, string parent);
+}
+
 namespace Zeitgeist.Timestamp
 {
   [CCode (cname = "ZEITGEIST_TIMESTAMP_SECOND", cheader_filename = "zeitgeist.h")]

=== modified file 'bindings/zeitgeist-1.0.gi'
--- bindings/zeitgeist-1.0.gi	2010-07-23 13:21:14 +0000
+++ bindings/zeitgeist-1.0.gi	2010-08-09 22:06:44 +0000
@@ -34,6 +34,31 @@
 				<parameter name="manifestation_type" type="gchar*"/>
 			</parameters>
 		</function>
+		<function name="symbol_get_all_children" symbol="zeitgeist_symbol_get_all_children">
+			<return-type type="GList*"/>
+			<parameters>
+				<parameter name="symbol" type="gchar*"/>
+			</parameters>
+		</function>
+		<function name="symbol_get_children" symbol="zeitgeist_symbol_get_children">
+			<return-type type="GList*"/>
+			<parameters>
+				<parameter name="symbol" type="gchar*"/>
+			</parameters>
+		</function>
+		<function name="symbol_get_parents" symbol="zeitgeist_symbol_get_parents">
+			<return-type type="GList*"/>
+			<parameters>
+				<parameter name="symbol" type="gchar*"/>
+			</parameters>
+		</function>
+		<function name="symbol_is_a" symbol="zeitgeist_symbol_is_a">
+			<return-type type="gboolean"/>
+			<parameters>
+				<parameter name="symbol" type="gchar*"/>
+				<parameter name="parent" type="gchar*"/>
+			</parameters>
+		</function>
 		<function name="timestamp_for_now" symbol="zeitgeist_timestamp_for_now">
 			<return-type type="gint64"/>
 		</function>
@@ -105,7 +130,11 @@
 			<member name="ZEITGEIST_RESULT_TYPE_MOST_POPULAR_ACTOR" value="6"/>
 			<member name="ZEITGEIST_RESULT_TYPE_LEAST_POPULAR_ACTOR" value="7"/>
 			<member name="ZEITGEIST_RESULT_TYPE_MOST_RECENT_ACTOR" value="8"/>
-			<member name="ZEITGEIST_RESULT_TYPE_LEAST_RECENT_ACTOR" value="6"/>
+			<member name="ZEITGEIST_RESULT_TYPE_LEAST_RECENT_ACTOR" value="9"/>
+			<member name="ZEITGEIST_RESULT_TYPE_MOST_RECENT_ORIGIN" value="10"/>
+			<member name="ZEITGEIST_RESULT_TYPE_LEAST_RECENT_ORIGIN" value="11"/>
+			<member name="ZEITGEIST_RESULT_TYPE_MOST_POPULAR_ORIGIN" value="12"/>
+			<member name="ZEITGEIST_RESULT_TYPE_LEAST_POPULAR_ORIGIN" value="13"/>
 			<member name="ZEITGEIST_RESULT_TYPE_RELEVANCY" value="100"/>
 		</enum>
 		<enum name="ZeitgeistStorageState" type-name="ZeitgeistStorageState" get-type="zeitgeist_storage_state_get_type">

=== modified file 'bindings/zeitgeist-1.0.metadata'
--- bindings/zeitgeist-1.0.metadata	2010-07-22 09:21:47 +0000
+++ bindings/zeitgeist-1.0.metadata	2010-08-09 22:06:44 +0000
@@ -40,6 +40,10 @@
 zeitgeist_event_set_payload.payload transfer_ownership="1"
 zeitgeist_monitor_new.event_templates transfer_ownership="1"
 
+Zeitgeist.Symbol cheader_filename="zeitgeist.h"
+zeitgeist_symbol_get* hidden="1" #transfer_ownership="1" type_arguments="unowned string"
+zeitgeist_symbol_is_a hidden="1"
+
 zeitgeist_data_source_registry_*.cancellable nullable="1"
 zeitgeist_log_*.cancellable nullable="1"
 zeitgeist_index_*.cancellable nullable="1"

=== modified file 'bindings/zeitgeist-1.0.vapi'
--- bindings/zeitgeist-1.0.vapi	2010-08-05 13:08:34 +0000
+++ bindings/zeitgeist-1.0.vapi	2010-08-09 22:06:44 +0000
@@ -2,6 +2,17 @@
 
 [CCode (cprefix = "Zeitgeist", lower_case_cprefix = "zeitgeist_")]
 namespace Zeitgeist {
+	[CCode (cprefix = "ZeitgeistSymbol", lower_case_cprefix = "zeitgeist_symbol_")]
+	namespace Symbol {
+		[CCode (cheader_filename = "zeitgeist.h")]
+		public static GLib.List<weak string> get_all_children (string symbol);
+		[CCode (cheader_filename = "zeitgeist.h")]
+		public static GLib.List<weak string> get_children (string symbol);
+		[CCode (cheader_filename = "zeitgeist.h")]
+		public static GLib.List<weak string> get_parents (string symbol);
+		[CCode (cheader_filename = "zeitgeist.h")]
+		public static bool is_a (string symbol, string parent);
+	}
 	[CCode (cprefix = "ZeitgeistTimestamp", lower_case_cprefix = "zeitgeist_timestamp_")]
 	namespace Timestamp {
 		[CCode (cname = "ZEITGEIST_TIMESTAMP_DAY", cheader_filename = "zeitgeist.h")]

=== modified file 'doc/reference/zeitgeist-1.0-docs.sgml'
--- doc/reference/zeitgeist-1.0-docs.sgml	2010-07-22 18:08:43 +0000
+++ doc/reference/zeitgeist-1.0-docs.sgml	2010-08-09 22:06:44 +0000
@@ -23,6 +23,7 @@
     <title>Utility Functions</title>
     <xi:include href="xml/zeitgeist-mimetypes.xml"/>
     <xi:include href="xml/zeitgeist-timestamp.xml"/>
+    <xi:include href="xml/zeitgeist-symbols.xml"/>
   </chapter>
   
   <chapter>

=== modified file 'doc/reference/zeitgeist-1.0-sections.txt'
--- doc/reference/zeitgeist-1.0-sections.txt	2010-07-22 18:08:43 +0000
+++ doc/reference/zeitgeist-1.0-sections.txt	2010-08-09 22:06:44 +0000
@@ -265,6 +265,15 @@
 </SECTION>
 
 <SECTION>
+<FILE>zeitgeist-symbols</FILE>
+<TITLE>Symbol comprehension</TITLE>
+zeitgeist_symbol_get_parents
+zeitgeist_symbol_get_children
+zeitgeist_symbol_get_all_children
+zeitgeist_symbol_is_a
+</SECTION>
+
+<SECTION>
 <FILE>zeitgeist-ontology-interpretations</FILE>
 <TITLE>Interpretation Ontology</TITLE>
 ZEITGEIST_NCAL_ALARM

=== modified file 'src/Makefile.am'
--- src/Makefile.am	2010-07-22 09:21:47 +0000
+++ src/Makefile.am	2010-08-09 22:06:44 +0000
@@ -134,6 +134,8 @@
   zeitgeist-result-set.c \
   zeitgeist-subject.c   \
   zeitgeist-subject.h   \
+  zeitgeist-symbols.c   \
+  zeitgeist-symbols.h   \
   zeitgeist-timerange.c   \
   zeitgeist-timerange.h   \
   zeitgeist-timestamp.c   \
@@ -165,6 +167,7 @@
   zeitgeist-ontology-manifestations.h \
   zeitgeist-result-set.h \
   zeitgeist-subject.h \
+  zeitgeist-symbols.h \
   zeitgeist-timerange.h \
   zeitgeist-timestamp.h \
   zeitgeist.h

=== added file 'src/zeitgeist-symbols.c'
--- src/zeitgeist-symbols.c	1970-01-01 00:00:00 +0000
+++ src/zeitgeist-symbols.c	2010-08-09 22:06:44 +0000
@@ -0,0 +1,1389 @@
+/*
+ * Copyright (C) 2010 Canonical, Ltd.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License
+ * version 3.0 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3.0 for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Authored by: Michal Hruby <[e-mail]>
+ */
+
+/**
+ * SECTION:zeitgeist-symbols
+ * @short_description: Used to get information about Interpretation and/or
+ *                     Manifestation symbols
+ * @include: zeitgeist.h
+ */
+
+#include "zeitgeist-ontology-interpretations.h"
+#include "zeitgeist-ontology-manifestations.h"
+#include "zeitgeist-symbols.h"
+
+static void _ensure_symbols_loaded   (void);
+
+static gboolean    symbols_loaded = FALSE;
+static GHashTable *symbol_uris    = NULL;
+
+typedef struct
+{
+  gchar *uri;
+  GSList *parents;
+  GSList *children;
+  GSList *all_children;
+} SymbolInfo;
+
+static SymbolInfo*
+symbol_info_new (gchar *uri,
+                 GStrv parents,
+                 GStrv children,
+                 GStrv all_children)
+{
+  gchar *iter;
+  SymbolInfo *i = g_slice_new0 (SymbolInfo);
+  i->uri = g_strdup (uri);
+
+  while (*parents)
+    {
+      i->parents = g_slist_append (i->parents,
+                                   GINT_TO_POINTER (g_quark_from_string (*parents)));
+      parents++;
+    }
+
+  while (*children)
+    {
+      i->children = g_slist_append (i->children,
+                                    GINT_TO_POINTER (g_quark_from_string (*children)));
+      children++;
+    }
+
+  while (*all_children)
+    {
+      i->all_children = g_slist_append (i->all_children,
+                                        GINT_TO_POINTER (g_quark_from_string (*all_children)));
+      all_children++;
+    }
+
+  return i;
+}
+
+static void 
+zeitgeist_register_symbol (SymbolInfo *i)
+{
+  if (symbol_uris == NULL)
+    symbol_uris = g_hash_table_new (g_str_hash, g_str_equal);
+
+  g_hash_table_insert (symbol_uris, i->uri, i);
+}
+
+/**
+ * zeitgeist_symbol_get_parents:
+ * @symbol: A symbol.
+ * 
+ * Gets list of parents of the specified symbol.
+ *
+ * Returns: A newly allocated list of parents of this symbol. 
+ *          The data elements of the list contain strings which you
+ *          do not own, use g_strdup() if you intend to work with them.
+ *          Free the list with a call to g_list_free().
+ */
+GList*
+zeitgeist_symbol_get_parents (const gchar *symbol)
+{
+  GSList *iter;
+  GList *result = NULL;
+  g_return_val_if_fail (symbol != NULL, NULL);
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, symbol);
+  g_return_val_if_fail (info != NULL, NULL);
+
+  for (iter = info->parents; iter; iter = iter->next)
+  {
+    result = g_list_prepend (result,
+                             g_quark_to_string (GPOINTER_TO_INT (iter->data)));
+  }
+
+  return g_list_reverse (result);
+}
+
+/**
+ * zeitgeist_symbol_get_children:
+ * @symbol: A symbol.
+ * 
+ * Gets list of direct children of the specified symbol.
+ *
+ * Returns: A newly allocated list of direct children of this symbol.
+ *          The data elements of the list contain strings which you
+ *          do not own, use g_strdup() if you intend to work with them.
+ *          Free the list with a call to g_list_free().
+ */
+GList*
+zeitgeist_symbol_get_children (const gchar *symbol)
+{
+  GSList *iter;
+  GList *result = NULL;
+  g_return_val_if_fail (symbol != NULL, NULL);
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, symbol);
+  g_return_val_if_fail (info != NULL, NULL);
+
+  for (iter = info->children; iter; iter = iter->next)
+  {
+    result = g_list_prepend (result,
+                             g_quark_to_string (GPOINTER_TO_INT (iter->data)));
+  }
+
+  return g_list_reverse (result);
+}
+
+/**
+ * zeitgeist_symbol_get_all_children:
+ * @symbol: A symbol.
+ * 
+ * Gets list of all children of the specified symbol.
+ *
+ * Returns: A newly allocated list of all children of this symbol (includes
+ *          also children of children).
+ *          The data elements of the list contain strings which you
+ *          do not own, use g_strdup() if you intend to work with them.
+ *          Free the list with a call to g_list_free().
+ */
+GList*
+zeitgeist_symbol_get_all_children (const gchar *symbol)
+{
+  GSList *iter;
+  GList *result = NULL;
+  g_return_val_if_fail (symbol != NULL, NULL);
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, symbol);
+  g_return_val_if_fail (info != NULL, NULL);
+
+  for (iter = info->all_children; iter; iter = iter->next)
+  {
+    result = g_list_prepend (result,
+                             g_quark_to_string (GPOINTER_TO_INT (iter->data)));
+  }
+
+  return g_list_reverse (result);
+}
+
+/**
+ * zeitgeist_symbol_is_a:
+ * @symbol: A symbol.
+ * @parent: Parent symbol.
+ * 
+ * Determines if @symbol is child of @parent.
+ *
+ * Returns: True if @symbol is child of @parent (or equal to @parent), 
+ *          FALSE otherwise.
+ */
+gboolean
+zeitgeist_symbol_is_a (const gchar *symbol, const gchar *parent)
+{
+  if (parent == NULL || symbol == NULL) return FALSE;
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, parent);
+  if (info == NULL) return FALSE;
+
+  GQuark symbol_quark = g_quark_try_string (symbol);
+  if (symbol_quark == 0) return FALSE;
+  // catch equal symbols
+  if (symbol_quark == g_quark_try_string (parent)) return TRUE;
+
+  return g_slist_find (info->all_children, GINT_TO_POINTER (symbol_quark)) != NULL;
+}
+
+static void
+_ensure_symbols_loaded (void)
+{
+  gchar **parents;
+  gchar **children;
+  gchar **all_children;
+  gchar *uri;
+  SymbolInfo *info;
+
+  if (symbols_loaded) return;
+
+  uri = ZEITGEIST_NFO_EXECUTABLE;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_SPREADSHEET;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_MODIFY_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_TRASH;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DATA_CONTAINER;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMO_MESSAGE;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NMO_EMAIL;
+  children[1] = ZEITGEIST_NMO_IMMESSAGE;
+  children[2] = NULL;
+  all_children = g_new (char*, 3);
+  all_children[0] = ZEITGEIST_NMO_EMAIL;
+  all_children[1] = ZEITGEIST_NMO_IMMESSAGE;
+  all_children[2] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_WEBSITE;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_TODO;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_CREATE_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_MEDIA_LIST;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 2);
+  children[0] = ZEITGEIST_NMM_MUSIC_ALBUM;
+  children[1] = NULL;
+  all_children = g_new (char*, 2);
+  all_children[0] = ZEITGEIST_NMM_MUSIC_ALBUM;
+  all_children[1] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_FILESYSTEM;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DATA_CONTAINER;
+  parents[1] = NULL;
+  children = g_new (char*, 2);
+  children[0] = ZEITGEIST_NFO_FILESYSTEM_IMAGE;
+  children[1] = NULL;
+  all_children = g_new (char*, 2);
+  all_children[0] = ZEITGEIST_NFO_FILESYSTEM_IMAGE;
+  all_children[1] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_MIND_MAP;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_CALENDAR;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_BOOKMARK;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMO_IMMESSAGE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NMO_MESSAGE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_EVENT;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_LEAVE_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_ARCHIVE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DATA_CONTAINER;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_ACCESS_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_VECTOR_IMAGE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_IMAGE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_CURSOR;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_RASTER_IMAGE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_VIDEO;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_VISUAL;
+  parents[1] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NMM_TVSHOW;
+  children[1] = ZEITGEIST_NMM_MOVIE;
+  children[2] = NULL;
+  all_children = g_new (char*, 3);
+  all_children[0] = ZEITGEIST_NMM_TVSHOW;
+  all_children[1] = ZEITGEIST_NMM_MOVIE;
+  all_children[2] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_BOOKMARK_FOLDER;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_HTML_DOCUMENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_PLAIN_TEXT_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_PLAIN_TEXT_DOCUMENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_TEXT_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NFO_SOURCE_CODE;
+  children[1] = ZEITGEIST_NFO_HTML_DOCUMENT;
+  children[2] = NULL;
+  all_children = g_new (char*, 3);
+  all_children[0] = ZEITGEIST_NFO_SOURCE_CODE;
+  all_children[1] = ZEITGEIST_NFO_HTML_DOCUMENT;
+  all_children[2] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_FONT;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_DATA_CONTAINER;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 5);
+  children[0] = ZEITGEIST_NFO_FILESYSTEM;
+  children[1] = ZEITGEIST_NFO_ARCHIVE;
+  children[2] = ZEITGEIST_NFO_FOLDER;
+  children[3] = ZEITGEIST_NFO_TRASH;
+  children[4] = NULL;
+  all_children = g_new (char*, 6);
+  all_children[0] = ZEITGEIST_NFO_FILESYSTEM_IMAGE;
+  all_children[1] = ZEITGEIST_NFO_ARCHIVE;
+  all_children[2] = ZEITGEIST_NFO_FOLDER;
+  all_children[3] = ZEITGEIST_NFO_TRASH;
+  all_children[4] = ZEITGEIST_NFO_FILESYSTEM;
+  all_children[5] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_RASTER_IMAGE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_IMAGE;
+  parents[1] = NULL;
+  children = g_new (char*, 2);
+  children[0] = ZEITGEIST_NFO_CURSOR;
+  children[1] = NULL;
+  all_children = g_new (char*, 2);
+  all_children[0] = ZEITGEIST_NFO_CURSOR;
+  all_children[1] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_IMAGE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_VISUAL;
+  parents[1] = NULL;
+  children = g_new (char*, 4);
+  children[0] = ZEITGEIST_NFO_ICON;
+  children[1] = ZEITGEIST_NFO_VECTOR_IMAGE;
+  children[2] = ZEITGEIST_NFO_RASTER_IMAGE;
+  children[3] = NULL;
+  all_children = g_new (char*, 5);
+  all_children[0] = ZEITGEIST_NFO_ICON;
+  all_children[1] = ZEITGEIST_NFO_VECTOR_IMAGE;
+  all_children[2] = ZEITGEIST_NFO_CURSOR;
+  all_children[3] = ZEITGEIST_NFO_RASTER_IMAGE;
+  all_children[4] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 8);
+  children[0] = ZEITGEIST_ZG_LEAVE_EVENT;
+  children[1] = ZEITGEIST_ZG_MODIFY_EVENT;
+  children[2] = ZEITGEIST_ZG_CREATE_EVENT;
+  children[3] = ZEITGEIST_ZG_SEND_EVENT;
+  children[4] = ZEITGEIST_ZG_ACCESS_EVENT;
+  children[5] = ZEITGEIST_ZG_DELETE_EVENT;
+  children[6] = ZEITGEIST_ZG_RECEIVE_EVENT;
+  children[7] = NULL;
+  all_children = g_new (char*, 8);
+  all_children[0] = ZEITGEIST_ZG_LEAVE_EVENT;
+  all_children[1] = ZEITGEIST_ZG_MODIFY_EVENT;
+  all_children[2] = ZEITGEIST_ZG_CREATE_EVENT;
+  all_children[3] = ZEITGEIST_ZG_SEND_EVENT;
+  all_children[4] = ZEITGEIST_ZG_ACCESS_EVENT;
+  all_children[5] = ZEITGEIST_ZG_DELETE_EVENT;
+  all_children[6] = ZEITGEIST_ZG_RECEIVE_EVENT;
+  all_children[7] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_SEND_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_APPLICATION;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_SOFTWARE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_DOCUMENT;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 5);
+  children[0] = ZEITGEIST_NFO_TEXT_DOCUMENT;
+  children[1] = ZEITGEIST_NFO_PRESENTATION;
+  children[2] = ZEITGEIST_NFO_MIND_MAP;
+  children[3] = ZEITGEIST_NFO_SPREADSHEET;
+  children[4] = NULL;
+  all_children = g_new (char*, 9);
+  all_children[0] = ZEITGEIST_NFO_SOURCE_CODE;
+  all_children[1] = ZEITGEIST_NFO_SPREADSHEET;
+  all_children[2] = ZEITGEIST_NFO_PAGINATED_TEXT_DOCUMENT;
+  all_children[3] = ZEITGEIST_NFO_TEXT_DOCUMENT;
+  all_children[4] = ZEITGEIST_NFO_HTML_DOCUMENT;
+  all_children[5] = ZEITGEIST_NFO_MIND_MAP;
+  all_children[6] = ZEITGEIST_NFO_PLAIN_TEXT_DOCUMENT;
+  all_children[7] = ZEITGEIST_NFO_PRESENTATION;
+  all_children[8] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMM_MUSIC_PIECE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_MEDIA;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMO_MAILBOX;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_TEXT_DOCUMENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NFO_PAGINATED_TEXT_DOCUMENT;
+  children[1] = ZEITGEIST_NFO_PLAIN_TEXT_DOCUMENT;
+  children[2] = NULL;
+  all_children = g_new (char*, 5);
+  all_children[0] = ZEITGEIST_NFO_SOURCE_CODE;
+  all_children[1] = ZEITGEIST_NFO_HTML_DOCUMENT;
+  all_children[2] = ZEITGEIST_NFO_PAGINATED_TEXT_DOCUMENT;
+  all_children[3] = ZEITGEIST_NFO_PLAIN_TEXT_DOCUMENT;
+  all_children[4] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_FILESYSTEM_IMAGE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_FILESYSTEM;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_JOURNAL;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_ICON;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_IMAGE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_PRESENTATION;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMM_MUSIC_ALBUM;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_MEDIA_LIST;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_SOURCE_CODE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_PLAIN_TEXT_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_VISUAL;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_MEDIA;
+  parents[1] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NFO_IMAGE;
+  children[1] = ZEITGEIST_NFO_VIDEO;
+  children[2] = NULL;
+  all_children = g_new (char*, 9);
+  all_children[0] = ZEITGEIST_NMM_TVSHOW;
+  all_children[1] = ZEITGEIST_NFO_VECTOR_IMAGE;
+  all_children[2] = ZEITGEIST_NFO_VIDEO;
+  all_children[3] = ZEITGEIST_NMM_MOVIE;
+  all_children[4] = ZEITGEIST_NFO_CURSOR;
+  all_children[5] = ZEITGEIST_NFO_ICON;
+  all_children[6] = ZEITGEIST_NFO_IMAGE;
+  all_children[7] = ZEITGEIST_NFO_RASTER_IMAGE;
+  all_children[8] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMO_EMAIL;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NMO_MESSAGE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_PAGINATED_TEXT_DOCUMENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_TEXT_DOCUMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMM_TVSHOW;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_VIDEO;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMM_TVSERIES;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_AUDIO;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_MEDIA;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_OPERATING_SYSTEM;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_SOFTWARE;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_SOFTWARE;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NFO_APPLICATION;
+  children[1] = ZEITGEIST_NFO_OPERATING_SYSTEM;
+  children[2] = NULL;
+  all_children = g_new (char*, 3);
+  all_children[0] = ZEITGEIST_NFO_OPERATING_SYSTEM;
+  all_children[1] = ZEITGEIST_NFO_APPLICATION;
+  all_children[2] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMM_MOVIE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_VIDEO;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_TIMEZONE;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_ALARM;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_FOLDER;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_DATA_CONTAINER;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMO_MIME_ENTITY;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_FREEBUSY;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_MEDIA;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 4);
+  children[0] = ZEITGEIST_NFO_VISUAL;
+  children[1] = ZEITGEIST_NFO_AUDIO;
+  children[2] = ZEITGEIST_NMM_MUSIC_PIECE;
+  children[3] = NULL;
+  all_children = g_new (char*, 12);
+  all_children[0] = ZEITGEIST_NMM_TVSHOW;
+  all_children[1] = ZEITGEIST_NMM_MUSIC_PIECE;
+  all_children[2] = ZEITGEIST_NFO_AUDIO;
+  all_children[3] = ZEITGEIST_NFO_VECTOR_IMAGE;
+  all_children[4] = ZEITGEIST_NFO_VIDEO;
+  all_children[5] = ZEITGEIST_NMM_MOVIE;
+  all_children[6] = ZEITGEIST_NFO_VISUAL;
+  all_children[7] = ZEITGEIST_NFO_CURSOR;
+  all_children[8] = ZEITGEIST_NFO_ICON;
+  all_children[9] = ZEITGEIST_NFO_IMAGE;
+  all_children[10] = ZEITGEIST_NFO_RASTER_IMAGE;
+  all_children[11] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_DELETE_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_RECEIVE_EVENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_INTERPRETATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_HARD_DISK_PARTITION;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_ARCHIVE_ITEM;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_EMBEDDED_FILE_DATA_OBJECT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_FILE_DATA_OBJECT;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 4);
+  children[0] = ZEITGEIST_NFO_EMBEDDED_FILE_DATA_OBJECT;
+  children[1] = ZEITGEIST_NFO_DELETED_RESOURCE;
+  children[2] = ZEITGEIST_NFO_REMOTE_DATA_OBJECT;
+  children[3] = NULL;
+  all_children = g_new (char*, 6);
+  all_children[0] = ZEITGEIST_NFO_EMBEDDED_FILE_DATA_OBJECT;
+  all_children[1] = ZEITGEIST_NFO_ARCHIVE_ITEM;
+  all_children[2] = ZEITGEIST_NFO_DELETED_RESOURCE;
+  all_children[3] = ZEITGEIST_NCAL_ATTACHMENT;
+  all_children[4] = ZEITGEIST_NFO_REMOTE_DATA_OBJECT;
+  all_children[5] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_SOFTWARE_SERVICE;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_SCHEDULED_ACTIVITY;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_MANIFESTATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_MEDIA_STREAM;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_EMBEDDED_FILE_DATA_OBJECT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_FILE_DATA_OBJECT;
+  parents[1] = NULL;
+  children = g_new (char*, 3);
+  children[0] = ZEITGEIST_NFO_ARCHIVE_ITEM;
+  children[1] = ZEITGEIST_NFO_ATTACHMENT;
+  children[2] = NULL;
+  all_children = g_new (char*, 3);
+  all_children[0] = ZEITGEIST_NFO_ARCHIVE_ITEM;
+  all_children[1] = ZEITGEIST_NCAL_ATTACHMENT;
+  all_children[2] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_ATTACHMENT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_ATTACHMENT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_HEURISTIC_ACTIVITY;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_MANIFESTATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_REMOTE_DATA_OBJECT;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_FILE_DATA_OBJECT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_EVENT_MANIFESTATION;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 6);
+  children[0] = ZEITGEIST_ZG_USER_ACTIVITY;
+  children[1] = ZEITGEIST_ZG_SYSTEM_NOTIFICATION;
+  children[2] = ZEITGEIST_ZG_HEURISTIC_ACTIVITY;
+  children[3] = ZEITGEIST_ZG_SCHEDULED_ACTIVITY;
+  children[4] = ZEITGEIST_ZG_WORLD_ACTIVITY;
+  children[5] = NULL;
+  all_children = g_new (char*, 6);
+  all_children[0] = ZEITGEIST_ZG_USER_ACTIVITY;
+  all_children[1] = ZEITGEIST_ZG_WORLD_ACTIVITY;
+  all_children[2] = ZEITGEIST_ZG_HEURISTIC_ACTIVITY;
+  all_children[3] = ZEITGEIST_ZG_SCHEDULED_ACTIVITY;
+  all_children[4] = ZEITGEIST_ZG_SYSTEM_NOTIFICATION;
+  all_children[5] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NMO_MAILBOX_DATA_OBJECT;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NCAL_CALENDAR_DATA_OBJECT;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_USER_ACTIVITY;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_MANIFESTATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_REMOTE_PORT_ADDRESS;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_WORLD_ACTIVITY;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_MANIFESTATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_SOFTWARE_ITEM;
+  parents = g_new (char*, 1);
+  parents[0] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_NFO_DELETED_RESOURCE;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_NFO_FILE_DATA_OBJECT;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+  uri = ZEITGEIST_ZG_SYSTEM_NOTIFICATION;
+  parents = g_new (char*, 2);
+  parents[0] = ZEITGEIST_ZG_EVENT_MANIFESTATION;
+  parents[1] = NULL;
+  children = g_new (char*, 1);
+  children[0] = NULL;
+  all_children = g_new (char*, 1);
+  all_children[0] = NULL;
+  info = symbol_info_new (uri, parents, children, all_children);
+  zeitgeist_register_symbol (info);
+  g_free (parents);
+  g_free (children);
+  g_free (all_children);
+
+
+  symbols_loaded = TRUE;
+}
+

=== added file 'src/zeitgeist-symbols.h'
--- src/zeitgeist-symbols.h	1970-01-01 00:00:00 +0000
+++ src/zeitgeist-symbols.h	2010-08-09 22:06:44 +0000
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2010 Canonical, Ltd.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License
+ * version 3.0 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3.0 for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Authored by: Michal Hruby <[e-mail]>
+ */
+
+#if !defined (_ZEITGEIST_H_INSIDE_) && !defined (ZEITGEIST_COMPILATION)
+#error "Only <zeitgeist.h> can be included directly."
+#endif
+
+#ifndef _ZEITGEIST_SYMBOLS_H_
+#define _ZEITGEIST_SYMBOLS_H_
+
+#include <glib.h>
+#include <glib-object.h>
+
+G_BEGIN_DECLS
+
+GList*   zeitgeist_symbol_get_parents (const gchar *symbol);
+
+GList*   zeitgeist_symbol_get_children (const gchar *symbol);
+
+GList*   zeitgeist_symbol_get_all_children (const gchar *symbol);
+
+gboolean zeitgeist_symbol_is_a (const gchar *symbol, const gchar *parent);
+
+G_END_DECLS
+
+#endif /* _ZEITGEIST_SYMBOLS_H_ */

=== modified file 'src/zeitgeist.h'
--- src/zeitgeist.h	2010-07-22 09:21:47 +0000
+++ src/zeitgeist.h	2010-08-09 22:06:44 +0000
@@ -36,6 +36,7 @@
 #include <zeitgeist-ontology-manifestations.h>
 #include <zeitgeist-result-set.h>
 #include <zeitgeist-subject.h>
+#include <zeitgeist-symbols.h>
 #include <zeitgeist-timerange.h>
 #include <zeitgeist-timestamp.h>
 

=== modified file 'tests/Makefile.am'
--- tests/Makefile.am	2010-07-22 09:21:47 +0000
+++ tests/Makefile.am	2010-08-09 22:06:44 +0000
@@ -40,6 +40,10 @@
 test_timestamp_SOURCES = test-timestamp.c $(helper_sources)
 test_timestamp_LDADD   = $(zeitgeist_libs)
 
+TEST_PROGS            += test-symbols
+test_symbols_SOURCES = test-symbols.c $(helper_sources)
+test_symbols_LDADD   = $(zeitgeist_libs)
+
 TEST_PROGS          += test-monitor
 test_monitor_SOURCES = test-monitor.c $(helper_sources)
 test_monitor_LDADD   = $(zeitgeist_libs)

=== added file 'tests/test-symbols.c'
--- tests/test-symbols.c	1970-01-01 00:00:00 +0000
+++ tests/test-symbols.c	2010-08-09 22:06:44 +0000
@@ -0,0 +1,220 @@
+/*
+ * Copyright (C) 2010 Canonical Ltd
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authored by Michal Hruby <[e-mail]>
+ *
+ */
+
+#include <glib.h>
+#include <glib-object.h>
+#include <string.h>
+#include "zeitgeist-symbols.h"
+#include "zeitgeist-ontology-interpretations.h"
+
+typedef struct
+{
+  
+} Fixture;
+
+static void setup    (Fixture *fix, gconstpointer data);
+static void teardown (Fixture *fix, gconstpointer data);
+
+static void
+setup (Fixture *fix, gconstpointer data)
+{
+  
+}
+
+static void
+teardown (Fixture *fix, gconstpointer data)
+{
+  
+}
+
+static void
+test_null_symbols (Fixture *fix, gconstpointer data)
+{
+  // shouldn't crash
+  zeitgeist_symbol_is_a (NULL, NULL);
+}
+
+static void
+test_null_first (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a (NULL, ZEITGEIST_NFO_MEDIA);
+
+  g_assert_cmpint (res, ==, FALSE);
+}
+
+static void
+test_null_second (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a (ZEITGEIST_NFO_MEDIA, NULL);
+
+  g_assert_cmpint (res, ==, FALSE);
+}
+
+static void
+test_not_uri (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a ("first", "second");
+
+  g_assert_cmpint (res, ==, FALSE);
+}
+
+static void
+test_not_uri_equal (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a ("something", "something");
+
+  g_assert_cmpint (res, ==, FALSE);
+}
+
+static void
+test_uris_equal (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a (ZEITGEIST_NFO_AUDIO,
+                                        ZEITGEIST_NFO_AUDIO);
+
+  g_assert_cmpint (res, ==, TRUE);
+}
+
+static void
+test_vector_image_media (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a (ZEITGEIST_NFO_VECTOR_IMAGE,
+                                        ZEITGEIST_NFO_MEDIA);
+
+  g_assert_cmpint (res, ==, TRUE);
+}
+
+static void
+test_media_vector_image (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a (ZEITGEIST_NFO_MEDIA,
+                                        ZEITGEIST_NFO_VECTOR_IMAGE);
+
+  g_assert_cmpint (res, ==, FALSE);
+}
+
+static void
+test_media_software (Fixture *fix, gconstpointer data)
+{
+  gboolean res = zeitgeist_symbol_is_a (ZEITGEIST_NFO_MEDIA,
+                                        ZEITGEIST_NFO_SOFTWARE);
+
+  g_assert_cmpint (res, ==, FALSE);
+}
+
+static void
+is_uri_valid (gpointer data, gpointer unused)
+{
+  const gchar SEM_D_URI[] = "http://www.semanticdesktop.org/ontologies";
+  gchar *uri = (gchar*) data;
+  g_assert (uri != NULL && g_str_has_prefix (uri, SEM_D_URI));
+  gchar *str = g_strdup_printf ("%s", uri);
+
+  g_free (str);
+}
+
+static void
+test_media_children (Fixture *fix, gconstpointer data)
+{
+  GList* children = zeitgeist_symbol_get_children (ZEITGEIST_NFO_MEDIA);
+
+  g_assert_cmpint (g_list_length (children), >, 0);
+  g_list_foreach (children, is_uri_valid, NULL);
+
+  g_list_free (children);
+}
+
+static void
+test_media_all_children (Fixture *fix, gconstpointer data)
+{
+  GList* children = zeitgeist_symbol_get_all_children (ZEITGEIST_NFO_MEDIA);
+
+  g_assert_cmpint (g_list_length (children), >, 0);
+  g_list_foreach (children, is_uri_valid, NULL);
+
+  g_list_free (children);
+}
+
+static void
+test_vector_image_parents (Fixture *fix, gconstpointer data)
+{
+  GList* parents = zeitgeist_symbol_get_parents (ZEITGEIST_NFO_VECTOR_IMAGE);
+
+  g_assert_cmpint (g_list_length (parents), >, 0);
+  g_list_foreach (parents, is_uri_valid, NULL);
+
+  g_list_free (parents);
+}
+
+static void
+test_media_complex (Fixture *fix, gconstpointer data)
+{
+  GList* iter;
+  GList* children = zeitgeist_symbol_get_children (ZEITGEIST_NFO_MEDIA);
+  GList* all_ch = zeitgeist_symbol_get_all_children (ZEITGEIST_NFO_MEDIA);
+
+  g_assert_cmpint (g_list_length (children), >, 0);
+  g_assert_cmpint (g_list_length (all_ch), >, g_list_length (children));
+
+  for (iter = children; iter; iter = iter->next)
+  {
+    // check that it's also in all_children
+    g_assert (g_list_find_custom (all_ch, iter->data, (GCompareFunc) strcmp));
+  }
+
+  g_list_free (all_ch);
+  g_list_free (children);
+}
+
+int
+main (int   argc,
+      char *argv[])
+{
+  g_type_init ();
+  g_test_init (&argc, &argv, NULL);
+  
+  g_test_add ("/Zeitgeist/Symbols/NullNull", Fixture, NULL,
+              setup, test_null_symbols, teardown);
+  g_test_add ("/Zeitgeist/Symbols/FirstNull", Fixture, NULL,
+              setup, test_null_first, teardown);
+  g_test_add ("/Zeitgeist/Symbols/SecondNull", Fixture, NULL,
+              setup, test_null_second, teardown);
+  g_test_add ("/Zeitgeist/Symbols/NotUris", Fixture, NULL,
+              setup, test_not_uri, teardown);
+  g_test_add ("/Zeitgeist/Symbols/NotUrisEqual", Fixture, NULL,
+              setup, test_not_uri_equal, teardown);
+  g_test_add ("/Zeitgeist/Symbols/EqualUris", Fixture, NULL,
+              setup, test_uris_equal, teardown);
+  g_test_add ("/Zeitgeist/Symbols/ValidParent", Fixture, NULL,
+              setup, test_vector_image_media, teardown);
+  g_test_add ("/Zeitgeist/Symbols/ValidChild", Fixture, NULL,
+              setup, test_media_vector_image, teardown);
+  g_test_add ("/Zeitgeist/Symbols/Unrelated", Fixture, NULL,
+              setup, test_media_software, teardown);
+  g_test_add ("/Zeitgeist/Symbols/GetChildren", Fixture, NULL,
+              setup, test_media_children, teardown);
+  g_test_add ("/Zeitgeist/Symbols/GetAllChildren", Fixture, NULL,
+              setup, test_media_all_children, teardown);
+  g_test_add ("/Zeitgeist/Symbols/GetParents", Fixture, NULL,
+              setup, test_vector_image_parents, teardown);
+  g_test_add ("/Zeitgeist/Symbols/SymbolInfo", Fixture, NULL,
+              setup, test_media_complex, teardown);
+  
+  return g_test_run();
+}

=== added file 'tools/symboltree2c.py'
--- tools/symboltree2c.py	1970-01-01 00:00:00 +0000
+++ tools/symboltree2c.py	2010-08-09 22:06:44 +0000
@@ -0,0 +1,107 @@
+#
+# Utility to transcode the Zeitgeist ontology from Python code
+# to a C header file defining a collection of macros for the
+# members of the ontology
+#
+
+import sys
+import re
+import zeitgeist.datamodel as dm
+
+def caseconv(name):
+	"""
+	Converts CamelCase to CAMEL_CASE
+	"""
+	result = ""
+	for i in range(len(name) - 1) :
+		if name[i].islower() and name[i+1].isupper():
+			result += name[i].upper() + "_"
+		else:
+			result += name[i].upper()
+	result += name[-1].upper()
+	return result
+
+def symbolname (symbol):
+	try:
+		ns, name = symbol[symbol.rfind("/")+1:].split("#")
+		return "ZEITGEIST_%s_%s" % (ns.upper(), caseconv(name))
+	except Exception, e:
+		return symbol.uri.rpartition("#")[2].upper()
+
+def output_symbol_func (body):
+	header = """
+static void
+_ensure_symbols_loaded (void)
+{
+  gchar **parents;
+  gchar **children;
+  gchar **all_children;
+  gchar *uri;
+  SymbolInfo *info;
+
+  if (symbols_loaded) return;
+
+%s
+
+  symbols_loaded = TRUE;
+}
+"""
+
+	# indent
+	symbols_func = header[1:] % re.sub(r'(?m)^(.+)$', r'  \1', body)
+	return symbols_func
+
+def get_symbols (l):
+	s = filter(lambda x: x not in [dm.Interpretation, dm.Manifestation], l)
+	s = map(symbolname, s)
+	s.append("NULL")
+
+	return s
+
+def alloc_array (name, symbols):
+	num_elems = len(symbols)
+	alloc_call = '%s = g_new (char*, %d);' % (name, num_elems)
+	elems = ['%s[%d] = %s;' % (name,i,symbols[i]) for i in xrange(0, num_elems)]
+	elems.insert(0, alloc_call)
+	return '\n'.join(elems)
+
+def register_symbol (symbol):
+	uri = 'uri = %s;' % symbolname(symbol)
+	arrays = ['parents', 'children', 'all_children']
+	parents = alloc_array(arrays[0], get_symbols(symbol.get_parents()))
+	children = alloc_array(arrays[1], get_symbols(symbol.get_children()))
+	all_ch = alloc_array(arrays[2], get_symbols(symbol.get_all_children()))
+
+	si_call = 'info = symbol_info_new (uri, parents, children, all_children);'
+	register_call = 'zeitgeist_register_symbol (info);'
+
+	calls = [uri, parents, children, all_ch, si_call, register_call]
+	calls.extend(['g_free (%s);' % var for var in arrays])
+
+	return '\n'.join(calls) + '\n'
+
+if __name__ == "__main__":
+	interpretations = []
+	manifestations = []
+	for interp in dm.Interpretation.get_all_children():
+		try:
+			stmt = register_symbol (interp)
+			interpretations.append(stmt)
+		except Exception, e:
+			print >> sys.stderr, "Failed to convert %s: %s" % (interp, e)
+
+	for manif in dm.Manifestation.get_all_children():
+		try:
+			stmt = register_symbol (manif)
+			manifestations.append(stmt)
+		except Exception, e:
+			print >> sys.stderr, "Failed to convert %s: %s" % (manif, e)
+
+
+	all_symbols = []
+	all_symbols.extend(interpretations)
+	all_symbols.extend(manifestations)
+
+	f = open('zeitgeist-symbols.template', 'r')
+	print f.read()
+	print output_symbol_func('\n'.join(all_symbols))

=== added file 'tools/zeitgeist-symbols.template'
--- tools/zeitgeist-symbols.template	1970-01-01 00:00:00 +0000
+++ tools/zeitgeist-symbols.template	2010-08-09 22:06:44 +0000
@@ -0,0 +1,210 @@
+/*
+ * Copyright (C) 2010 Canonical, Ltd.
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License
+ * version 3.0 as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License version 3.0 for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * Authored by: Michal Hruby <[e-mail]>
+ */
+
+/**
+ * SECTION:zeitgeist-symbols
+ * @short_description: Used to get information about Interpretation and/or
+ *                     Manifestation symbols
+ * @include: zeitgeist.h
+ */
+
+#include "zeitgeist-ontology-interpretations.h"
+#include "zeitgeist-ontology-manifestations.h"
+#include "zeitgeist-symbols.h"
+
+static void _ensure_symbols_loaded   (void);
+
+static gboolean    symbols_loaded = FALSE;
+static GHashTable *symbol_uris    = NULL;
+
+typedef struct
+{
+  gchar *uri;
+  GSList *parents;
+  GSList *children;
+  GSList *all_children;
+} SymbolInfo;
+
+static SymbolInfo*
+symbol_info_new (gchar *uri,
+                 GStrv parents,
+                 GStrv children,
+                 GStrv all_children)
+{
+  gchar *iter;
+  SymbolInfo *i = g_slice_new0 (SymbolInfo);
+  i->uri = g_strdup (uri);
+
+  while (*parents)
+    {
+      i->parents = g_slist_append (i->parents,
+                                   GINT_TO_POINTER (g_quark_from_string (*parents)));
+      parents++;
+    }
+
+  while (*children)
+    {
+      i->children = g_slist_append (i->children,
+                                    GINT_TO_POINTER (g_quark_from_string (*children)));
+      children++;
+    }
+
+  while (*all_children)
+    {
+      i->all_children = g_slist_append (i->all_children,
+                                        GINT_TO_POINTER (g_quark_from_string (*all_children)));
+      all_children++;
+    }
+
+  return i;
+}
+
+static void 
+zeitgeist_register_symbol (SymbolInfo *i)
+{
+  if (symbol_uris == NULL)
+    symbol_uris = g_hash_table_new (g_str_hash, g_str_equal);
+
+  g_hash_table_insert (symbol_uris, i->uri, i);
+}
+
+/**
+ * zeitgeist_symbol_get_parents:
+ * @symbol: A symbol.
+ * 
+ * Gets list of parents of the specified symbol.
+ *
+ * Returns: A newly allocated list of parents of this symbol. 
+ *          The data elements of the list contain strings which you
+ *          do not own, use g_strdup() if you intend to work with them.
+ *          Free the list with a call to g_list_free().
+ */
+GList*
+zeitgeist_symbol_get_parents (const gchar *symbol)
+{
+  GSList *iter;
+  GList *result = NULL;
+  g_return_val_if_fail (symbol != NULL, NULL);
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, symbol);
+  g_return_val_if_fail (info != NULL, NULL);
+
+  for (iter = info->parents; iter; iter = iter->next)
+  {
+    result = g_list_prepend (result,
+                             g_quark_to_string (GPOINTER_TO_INT (iter->data)));
+  }
+
+  return g_list_reverse (result);
+}
+
+/**
+ * zeitgeist_symbol_get_children:
+ * @symbol: A symbol.
+ * 
+ * Gets list of direct children of the specified symbol.
+ *
+ * Returns: A newly allocated list of direct children of this symbol.
+ *          The data elements of the list contain strings which you
+ *          do not own, use g_strdup() if you intend to work with them.
+ *          Free the list with a call to g_list_free().
+ */
+GList*
+zeitgeist_symbol_get_children (const gchar *symbol)
+{
+  GSList *iter;
+  GList *result = NULL;
+  g_return_val_if_fail (symbol != NULL, NULL);
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, symbol);
+  g_return_val_if_fail (info != NULL, NULL);
+
+  for (iter = info->children; iter; iter = iter->next)
+  {
+    result = g_list_prepend (result,
+                             g_quark_to_string (GPOINTER_TO_INT (iter->data)));
+  }
+
+  return g_list_reverse (result);
+}
+
+/**
+ * zeitgeist_symbol_get_all_children:
+ * @symbol: A symbol.
+ * 
+ * Gets list of all children of the specified symbol.
+ *
+ * Returns: A newly allocated list of all children of this symbol (includes
+ *          also children of children).
+ *          The data elements of the list contain strings which you
+ *          do not own, use g_strdup() if you intend to work with them.
+ *          Free the list with a call to g_list_free().
+ */
+GList*
+zeitgeist_symbol_get_all_children (const gchar *symbol)
+{
+  GSList *iter;
+  GList *result = NULL;
+  g_return_val_if_fail (symbol != NULL, NULL);
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, symbol);
+  g_return_val_if_fail (info != NULL, NULL);
+
+  for (iter = info->all_children; iter; iter = iter->next)
+  {
+    result = g_list_prepend (result,
+                             g_quark_to_string (GPOINTER_TO_INT (iter->data)));
+  }
+
+  return g_list_reverse (result);
+}
+
+/**
+ * zeitgeist_symbol_is_a:
+ * @symbol: A symbol.
+ * @parent: Parent symbol.
+ * 
+ * Determines if @symbol is child of @parent.
+ *
+ * Returns: True if @symbol is child of @parent (or equal to @parent), 
+ *          FALSE otherwise.
+ */
+gboolean
+zeitgeist_symbol_is_a (const gchar *symbol, const gchar *parent)
+{
+  if (parent == NULL || symbol == NULL) return FALSE;
+
+  _ensure_symbols_loaded ();
+
+  SymbolInfo *info = (SymbolInfo*) g_hash_table_lookup (symbol_uris, parent);
+  if (info == NULL) return FALSE;
+
+  GQuark symbol_quark = g_quark_try_string (symbol);
+  if (symbol_quark == 0) return FALSE;
+  // catch equal symbols
+  if (symbol_quark == g_quark_try_string (parent)) return TRUE;
+
+  return g_slist_find (info->all_children, GINT_TO_POINTER (symbol_quark)) != NULL;
+}