EFFEKT

Effiziente Übersetzung von Kontrolleffekten

01/04/2021 to 31/03/2024

The history of programming language design and implementation is to a significant degree
the history of control structures. The last decade has seen a new proliferation of
advanced control structures, such as async/wait, generators, coroutines, or fibers. These
new control structures promise improved program structure (such as the avoidance of “callback hell”)
and generally a higher level of abstraction. However, the way such control structures
are implemented today is highly unsatisfactory. They are often hard-coded into a language,
(i.e., they are not user-definable), they are not composable (i.e., programs using different
abstractions cannot be combined in one project), or implementations for one control abstraction
cannot be reused to implement similar other control abstractions.
To resolve the aforementioned limitations, we embrace effect handlers as a high-level
control abstraction. Backed by a strong theoretical background and a static type- and effect
system, effect handlers encourage a modular definition of control abstractions as user-defineable
libraries and naturally allow users to compose these libraries in one program.
As of today, the abstraction of effect handlers comes with a cost in performance.
The goal of the ECCE project (Efficient Compilation of Control Effects) is to
remove these costs and provide “control-flow abstraction without regret”.
Specifically, we aim to establish a research programme to achieve
novel compile-time and just-in-time optimizations for effect handlers, accompanied by
both a theoretical framework to reason about correctness and costs as well as implementations
for realistic languages. Efficient effect handlers will enable programmers to develop many general
purpose, as well as domain specific control-flow constructs without
sacrificing performance.