X-Git-Url: http://nitlanguage.org

diff --git a/src/model/model_base.nit b/src/model/model_base.nit
index a51ec29..ae5553d 100644
--- a/src/model/model_base.nit
+++ b/src/model/model_base.nit
@@ -23,10 +23,20 @@ class Model
 end
 
 # A named and possibly documented entity in the model.
-# This class is usefull to generalize presentation of entities to the human.
+# This class is useful to generalize presentation of entities to the human.
 abstract class MEntity
 	# The short (unqualified) name of this model entity
 	fun name: String is abstract
+
+	# A Model Entity has a direct link to its model
+	fun model: Model is abstract
+end
+
+# Something that represents a concern
+abstract class MConcern
+	super MEntity
+	# The concern that contains `self` or null if `self` is the root of the concern hierarchy
+	fun parent_concern: nullable MConcern is abstract
 end
 
 # A visibility (for modules, class and properties)
@@ -36,6 +46,7 @@ end
 #  * `public_visibility`
 #  * `protected_visibility`
 #  * `none_visibility`
+#  * `private_visiblity`
 #
 # Note this class is basically an enum.
 # FIXME: use a real enum once user-defined enums are available
@@ -61,8 +72,13 @@ class MVisibility
 	end
 end
 
+# The visibility level `intrude`
 fun intrude_visibility: MVisibility do return once new MVisibility("intrude", 5)
+# The visibility level `public`
 fun public_visibility: MVisibility do return once new MVisibility("public", 4)
+# The visibility level `protected`
 fun protected_visibility: MVisibility do return once new MVisibility("protected", 3)
+# The visibility level `private`
 fun private_visibility: MVisibility do return once new MVisibility("private", 2)
+# The visibility level `none` (no visibility)
 fun none_visibility: MVisibility do return once new MVisibility("none", 1)