Work

Gradual session types

Year: 2019

Type: article

Abstract: Session types are a rich type discipline, based on linear types, that lifts the sort of safety claims that come with type systems to communications. However, web-based applications and microservices are often written in a mix of languages, with type disciplines in a spectrum between static and dynamic typing. Gradual session types address this mixed setting by providing a framework which grants seamless transition between statically typed handling of sessions and any required degree of dynamic typing. We propose Gradual GV as a gradually typed extension of the functional session type system GV. Following a standard framework of gradual typing, Gradual GV consists of an external language, which relaxes the type system of GV using dynamic types; an internal language with casts, for which operational semantics is given; and a cast-insertion translation from the former to the latter. We demonstrate type and communication safety as well as blame safety, thus extending previous results to functional languages with session-based communication. The interplay of linearity and dynamic types requires a novel approach to specifying the dynamics of the language.

Source: Journal of Functional Programming

DOI: 10.1017/s0956796819000169

Authors: ATSUSHI IGARASHI, PETER THIEMANN, YUYA TSUDA, VASCO T. VASCONCELOS, PHILIP WADLER

Institutions: University of Lisbon, University of Freiburg, Kyoto University, University of Edinburgh, Laboratório de Sistemas Informáticos de Grande Escala

Language: English

Topic: Logic, programming, and type systems

Subfield: Artificial Intelligence

Field: Computer Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $2,980

Funders: Engineering and Physical Sciences Research Council, Japan Society for the Promotion of Science, Fundação para a Ciência e a Tecnologia