diffJavaM3 signature

[linuswagner]

Currently, the signature of diffJavaM3 and diffM3 takes a location (identifier) and a list of metaModels. It then calculates the difference between the first model in the list and the union of the others.

The choice of the list seems questionable: The order of the elements after the first one does not matter. Developers need to know that in order to properly use the method.

It seems more logical to me to have this function written with three parameters:

• id
• M3 to compare against
• set of M3s to form diff with

This then makes it explicit that the order of the other models does not work and it also makes the signature closer to composeM3, which is conceptually similar.

[jurgenvinju]

You're right. Let's make it a function with two M3 model parameters. Then if someone needs a union as the second parameter they can first use composeM3 for that.