[henshin-dev] Excluded subtypes for nodes

[Christian Krause <henshin.ck@xxxxxxxxx>]

Hi,
I would like to add the following feature to Node:

- excludedSubTypes: EClass 0..*

The meaning is that for an object to be able to be matched, it must not 
inherit from any of the classes in this list (but of course it still 
must implement the class specified in the "type" attribute).

A concrete example: I want to define a transformation for the Henshin 
generator model. One rule should map a "TransformationUnit" to a 
"GenUnit". Another rule should map "Rule" to "GenRule". For the first 
rule I need to specify somehow that the matched unit is not a rule; so I 
need to exclude the subType "Rule" here.

The required modifications to the editors and the interpreter are 
minimal. Ok with you?

Ciao,
Christian