[henshin-dev] multiRule Interpreter

[Gregor Bonifer <gregor.bonifer@xxxxxx>]

Hi,

I checked in a beta version of the interpreter under 
branches/multiRuleInterpreter. Consider this a proposal! I made a change 
to Match that might be a bit controversial but works just fine. So, here 
is the outline of what I have done:
- private Map<Rule, List<Match>> Match.nestedMatches: A match holds a 
map that contains a collection of matches for each multiRules. For Rules 
without multiRules this simply remains empty.
- EmfEngine:
-- findMatch and findAllMatches work recursive to build a Match-tree 
using an altered version of prepareMatchFinder, that allows injecting 
usedObjects and prematches.
-- executeModelChanges accumulates the changes from a Match-tree into a 
ModelChange-Object that is passed recursively(much easier that merging 
two ChangeDescriptors). The traversal yields another Match-tree 
representing the comatch.

For this to work, there is one important constraint for the 
transformation model: As we discussed earlier, the kernel must not be 
mapped entirely into each multiRule. However, if a kernelNode is mapped 
inside the kernelRule(i.e. the node is preserved), either both or none 
of the kernelNodes must be mapped into a multiRule. In case both nodes 
are mapped there also has to be a mapping between the two inside the 
multiRule.

Regards,
Gregor