Publications by Lionel Emile Vincent Parreaux

When Subtyping Constraints Liberate A Novel Type Inference Approach for First-Class Polymorphism

Lionel Emile Vincent Parreaux, Aleksander Slawomir Boruch-Gruszecki

Type inference in the presence of first-class or "impredicative" second-order polymorphism a la System F has been an active research area for several decades, with original works dating back to the end of the 80s. Yet, until now many basic problems remain ...

Assoc Computing Machinery2024

A case for DOT: Theoretical Foundations for Objects with Pattern Matching and GADT-Style Reasoning

Lionel Emile Vincent Parreaux, Aleksander Slawomir Boruch-Gruszecki, Yichen Xu

Many programming languages in the OO tradition now support pattern matching in some form. Historical examples include Scala and Ceylon, with the more recent additions of Java, Kotlin, TypeScript, and Flow. But pattern matching on generic class hierarchies ...

Assoc Computing Machinery2022

The Simple Essence of Algebraic Subtyping: Principal Type Inference with Subtyping Made Easy

Lionel Emile Vincent Parreaux

MLsub extends traditional Hindley-Milner type inference with subtyping while preserving compact principal types, an exciting new development. However, its specification in terms of biunification is difficult to understand, relying on the new concepts of bi ...

2020

Type-Safe Metaprogramming and Compilation Techniques For Designing Efficient Systems in High-Level Languages

Lionel Emile Vincent Parreaux

Software engineering practices have been steadily moving towards higher-level programming languages and away from lower-level ones. High-level languages tend to greatly improve safety, productivity, and code maintainability because they handle various impl ...

EPFL2020

Towards Improved GADT Reasoning in Scala

Lionel Emile Vincent Parreaux, Paolo Giosuè Giarrusso, Aleksander Slawomir Boruch-Gruszecki

Generalized algebraic data types (GADT) have been notoriously difficult to implement correctly in Scala. Both major Scala compilers, Scalac and Dotty, are currently known to have type soundness holes related to them. In particular, covariant GADTs have exp ...

ASSOC COMPUTING MACHINERY2019

Finally, a Polymorphic Linear Algebra Language

Amir Shaikhha, Lionel Emile Vincent Parreaux

Many different data analytics tasks boil down to linear algebra primitives. In practice, for each different type of workload, data scientists use a particular specialised library. In this paper, we present Pilatus, a polymorphic iterative linear algebra la ...

2019

Unifying Analytic and Statically-Typed Quasiquotes

Christoph Koch, Amir Shaikhha, Lionel Emile Vincent Parreaux

Metaprograms are programs that manipulate (generate, analyze and evaluate) other programs. These tasks are greatly facilitated by quasiquotation, a technique to construct and deconstruct program fragments using quoted code templates expressed in the syntax ...

2018

Quoted Staged Rewriting: A Practical Approach to Library-Defined Optimizations

Christoph Koch, Amir Shaikhha, Lionel Emile Vincent Parreaux

Staging has proved a successful technique for programmatically removing code abstractions, thereby allowing for faster program execution while retaining a high-level interface for the programmer. Unfortunately, techniques based on staging suffer from a num ...

ACM2017

Squid: Type-Safe, Hygienic, and Reusable Quasiquotes

Christoph Koch, Amir Shaikhha, Lionel Emile Vincent Parreaux

Quasiquotes have been shown to greatly simplify the task of metaprogramming. This is in part because they hide the data structures of the intermediate representation (IR), instead allowing metaprogrammers to use the concrete syntax of the language they man ...

ACM2017

How to Architect a Query Compiler

Lewis Alexander Brown, Christoph Koch, Amir Shaikhha, Ioannis Klonatos, Mohammad Dashti Rahmat Abadi, Lionel Emile Vincent Parreaux

This paper studies architecting query compilers. The state of the art in query compiler construction is lagging behind that in the compilers field. We attempt to remedy this by exploring the key causes of technical challenges in need of well founded soluti ...

2016