Section: Overall Objectives
Constructs for modular and isolating programming languages
At the same time, there is a need for software isolation i.e.,, applications should reliably run co-located with other applications in the same virtual machine with neither confidential information leaks nor vulnerabilities. Indeed, often for economical reasons, web servers run multiple applications on the same virtual machine. Users need confined applications. It is important that (1) an application does not access information of other applications running on the same virtual machine and (2) an application authorized to manipulate data cannot pass such authorization or information to other parts of the application that should not get access to it.
Reflection and isolation concerns are a priori antagonistic, pulling language design in two opposite directions. Isolation, on the one hand, pulls towards more static elements and types (e.g.,, ownership types). Reflection, on the other hand, pulls towards fully dynamic behavior. This tension is what makes this a real challenge: As experts in reflective programming, dynamic languages and modular systems, we believe that by working on this important tension we can make a breakthrough and propose innovative solutions in resolving or mitigating this tension. With this endeavor, we believe that we are working on a key challenge that can have an impact on future programming languages. The language construct challenge tackled by RMoD is formulated as follows:
What are the language modularity constructs to support isolation?
In parallel we are continuing our research effort on traits (Traits are groups of methods that can be composed orthogonally to simple inheritance. Contrary to mixin, the class has the control of the composition and conflict management.) by assessing trait scalability and reuse on a large case study and developing a pure trait-based language. In addition, we dedicate efforts to remodularizing a meta-level architecture in the context of the design of an isolating dynamic language. Indeed at the extreme, modules and structural control of reflective features are the first steps towards flexible, dynamic, yet isolating, languages. As a result, we expect to demonstrate that having adequate composable units and scoping units will help the evolution and recomposition of an application.