Gradual type-and-effect systems

Abstract

Effect systems have the potential to help software developers, but their practical adoption has been very limited. We conjecture that this limited adoption is due in part to the difficulty of transitioning from a system where effects are implicit and unrestricted to a system with a static effect discipline, which must settle for conservative checking in order to be decidable. To address this hindrance, we develop a theory of gradual effect checking, which makes it possible to incrementally annotate and statically check effects, while still rejecting statically inconsistent programs. We extend the generic type-and-effect framework of Marino and Millstein with a notion of unknown effects, which turns out to be significantly more subtle than unknown types in traditional gradual typing. We appeal to abstract interpretation to develop and validate the concepts of gradual effect checking. We also demonstrate how an effect system formulated in the framework of Marino and Millstein can be automatically extended to support gradual checking. We use gradual effect checking to develop a fully gradual type-and-effect framework, which permits interaction between static and dynamic checking for both effects and types

Towards Gradually Typed Capabilities in the Pi-Calculus

“…There has been considerable work in gradual typing both from industry [3,9,27,4] and academia [18,24,26,14,17,1]. The challenge in capturing a calculus such as the π-calculus is that several output processes may compete for a single input.…”

Static Blame for gradual typing

“…The academic field is mainly dedicated to combining gradual typing with other language features, including both expressiveness (object (Siek & Taha, 2007; Chung et al ., 2018), effect (Bañados Schwerter et al ., 2014, 2016;Wadler, 2021), polymorphism (Ahmed et al ., 2011, 2017; Igarashi et al ., 2017), set theoretic types (Toro & Tanter, 2017; Castagna et al ., 2019)), and implementation optimization (Pycket (Bauman et al ., 2015), Grift (Kuhlenschmidt et al ., 2019)).…”