EVL: a typed functional language for event processing

TL;DR

EVL is a minimal typed functional language designed for flexible event processing, extending traditional event concepts with polymorphic records to support complex, higher-order event handling in various systems.

Contribution

It introduces EVL, a new higher-order functional language with polymorphic record types for generic event modeling and processing.

Findings

Demonstrates EVL's ability to handle complex event processing techniques

Shows EVL's applicability in access control and reactive systems

Provides a formal foundation for typed event specifications

Abstract

We define EVL, a minimal higher-order functional language to deal with generic events. The notion of generic event extends the well-known notion of event traditionally used in a variety of areas, such as database management, concurrency, reactive systems and cybersecurity. Generic events were introduced in the context of a metamodel to specify obligations in access control systems. Event specifications are represented as records and we use polymorphic record types to type events in EVL. We show how the higher-order capabilities of EVL can be used in the context of Complex Event Processing (CEP), to define higher-order parameterised functions that deal with the usual CEP techniques.