Implement DefinesQuantity for InstanceModel and DataDefinition

code/drasil-theory/lib/Theory/Drasil/DataDefinition.hs

@@ -71,6 +71,9 @@ instance HasUID             DataDefinition where uid = ddQD uid uid
 instance NamedIdea          DataDefinition where term = ddQD term term
 -- | Finds the idea contained in the 'QDefinition' used to make the 'DataDefinition where'.
 instance Idea               DataDefinition where getA = either getA getA . qdFromDD
+-- | Finds the 'Quantity' defined by the 'DataDefinition'
+instance DefinesQuantity    DataDefinition where
+  defLhs = ddQDGetter defLhs defLhs
 -- | Finds the output variable of the 'DataDefinition'
 instance HasOutput          DataDefinition where
   output = ddQDGetter defLhs defLhs

code/drasil-theory/lib/Theory/Drasil/InstanceModel.hs

@@ -70,6 +70,9 @@ instance CommonIdea         InstanceModel where abrv _ = abrv inModel
 instance Referable          InstanceModel where
   refAdd      = ra
   renderRef l = RP (prepend $ abrv l) (refAdd l)
+-- | Finds the 'Quantity' of an 'InstanceModel'
+instance DefinesQuantity    InstanceModel where
+  defLhs = imOutput . _1
 -- | Finds the inputs of an 'InstanceModel'.
 instance HasInputs          InstanceModel where
   inputs          = imInputs