Bug 441767

Description Pierre-Charles David 2014-08-14 05:47:36 EDT

The validation of Acceleo 3 expressions inside a VSM require type information for all the expressions' context and available variables. Currently we default to EObject in many cases, but a more precise analysis is technically possible.
In particular:
* We should support "Change Context" operations (and "New Instance" and more generally any operation which changes the context): the expressions which are inside such an element should have a context type corresponding to the result of the "Change Context" expression (as much as can be determined statically anyway).
* Many variables which refer to semantic elements are typed as EObject, but in most cases we know in the VSM the Domain Class of the corresponding mapping, so we should be able to be more precise (so that users do not have to prefix their expressions with filter(ExpectedType).

This impacts the interpreter/query API, which currently provides no way to associate a type to variables. At validation/static time, we default to EObject, and at runtime we use the actual instance type. We should be able to reify the expected type environement from the VSM and user meta-model, use this for validation and completion at sepcification time (inside the VSM), and also at runtime to compile only one variant of each Acceleo expression (currently each combination of concrete types seen by the Acceleo compiler at runtime produces a separate dynamic module).