It appears that UML user-defined datatypes are only supported when there
is a single property of the datatype with stereoptype <<javaclass>> and
the property refers to a fully qualified Java class that implements the
data type.
This means that the typical UML datatype definition doesn't get imported
into EMF properly. For example:
<<datatype>>
Date
-----------------------------
now : Date
-----------------------------
isBefore( t:Date ) : Boolean
isAfter( t:Date ) : Boolean
The above data type is rejected. Is this correct? Is this by design?