groupe_types are real types now

tiramisu/setting.py

@@ -21,11 +21,49 @@
 # the whole pypy projet is under MIT licence
 # ____________________________________________________________
 
-# available group_type values
-_group_name = ('default', 'family', 'group')
-groups_has_master = ('group', )
-class Group(str): pass
-group_types = tuple(Group(i) for i in _group_name)
+class _const:
+    """convenient class that emulates a module
+    and builds constants (that is, unique group names)"""
+    class GroupError(TypeError): pass
+
+    def __setattr__(self, name, value):
+        if self.__dict__.has_key(name):
+            raise self.GroupError, "Can't rebind group (%s)"%name
+        self.__dict__[name] = value
+
+    def __delattr__(self, name):
+        if self.__dict__.has_key(name):
+            raise self.GroupError, "Can't unbind group (%s)"%name
+        raise NameError, name
+
+groups = _const()
+def populate_groups():
+    "populates the available groups in the appropriate namespaces"
+    _available_group_names = ('default', 'family', 'group')
+    _available_groups_with_a_master = ('group', )
+    class GroupName(str):
+        """allowed normal group (OptionDescription) names
+        *normal* means : groups that are not master
+        """
+        pass
+
+    class MasterGroupName(GroupName):
+        """allowed normal group (OptionDescription) names
+        *master* means : groups that have the 'master' attribute set
+        """
+        pass
+
+    groups.GroupName = GroupName
+    groups.MasterGroupName = MasterGroupName
+    # populates normal or master groups
+    for grp in _available_group_names:
+        if grp in _available_groups_with_a_master:
+            setattr(groups, grp, MasterGroupName(grp))
+        else:
+            setattr(groups, grp, GroupName(grp))
+
+populate_groups()
+# ____________________________________________________________
 
 class Setting():
     "``Config()``'s configuration options"