The need for flexible forms of serialisation arises under many circumstances, e.g. for doing high-level inter-process communication or to achieve persistence. Many languages, including variants of ML, thus offer pickling as a system service, but usually in a both unsafe and inexpressive manner, so that its use is discouraged. In contrast, safe generic pickling plays a central role in the design and implementation of Alice ML: components are defined as pickles, and modules can be exchanged between processes using pickling. For that purpose, pickling has to be higher-order and typed (HOT), i.e. embrace code mobility and involve runtime type checks for safety. We show how HOT pickling can be realised with a modular architecture consisting of multiple abstraction layers for separating concerns, and how both language and implementation benefit from a design consistently based on pickling.
[TIMe - eMBEdded - Reactive] Timber is a general programming language specifically aimed at the construction of complex event-driven systems. It allows programs to be conveniently structured in terms of objects and reactions, and the real-time behavior of reactions can furthermore be precisely controlled via platform-independent timing constraints. This property makes Timber particularly suited to both the specification and the implementation of real-time embedded systems. Timber is deeply rooted in the functional programming tradition, although it also draws heavily on object-oriented concepts, and has the notion of concurrent execution built into its core.