Define interface between extension and Rascal

[bsddemon]

I want the extension to be generic.
The output of the Rascal scripts needs to be according some kind of interface.
Idea: "severity""file""line""column""message"

[jurgenvinju]

To make sure analysis remain portable between different IDEs we decided for now to standardize on the Message datatype in the standard library. Every analysis is a function that returns list[Message]. The input parameters can be more flexible. Perhaps we could stick with loc input and a default PathConfig in case libraries need to be considered during the analysis?

[jurgenvinju]

So any analysis function has this signature list[Message] (loc input, PathConfig pcfg=pathConfig()

[jurgenvinju]

Our code here can unpack the messages and visualize them in the IDE. We usually have an independent registerDiagnostics(list[Message] msgs) for that. Let's start writing that one?

[jurgenvinju]

If we want to be lazy then perhaps serializing the messages as XML or JSON is the fastest way is bridging then to the studio.

[jurgenvinju]

Btw for all generic IDE services we could implement see util::IDEServices