model: promote location to any `MEntity`

[nit.git] / src / model / model_base.nit

diff --git a/src/model/model_base.nit b/src/model/model_base.nit
index 5cfe9b2..0c136b8 100644 (file)
--- a/src/model/model_base.nit
+++ b/src/model/model_base.nit
@@ -16,6 +16,7 @@
 
 # The abstract concept of model and related common things
 module model_base
+import location
 
 # The container class of a Nit object-oriented model.
 # A model knows modules, classes and properties and can retrieve them.
@@ -23,6 +24,11 @@ class Model
        super MEntity
 
        redef fun model do return self
+
+       # Place-holder object that means no-location
+       #
+       # See `MEntity::location`
+       var no_location = new Location(null, 0, 0, 0, 0)
 end
 
 # A named and possibly documented entity in the model.
@@ -65,6 +71,16 @@ abstract class MEntity
        # indirect use should be restricted (e.g. to name a web-page)
        fun c_name: String is abstract
 
+       # The origin of the definition.
+       #
+       # Most model entities are defined in a specific place in the source base.
+       #
+       # Because most model entities have one,
+       # it is simpler for the client to have a non-nullable return value.
+       # For entities that lack a location, mock-up special locations are used instead.
+       # By default it is `model.no_location`.
+       fun location: Location do return model.no_location
+
        # A Model Entity has a direct link to its model
        fun model: Model is abstract