Concept

Covariance and contravariance (computer science)

Related publications (52)

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

Type-Preserving Compilation of Class-Based Languages

Guillaume André Fradji Martres

The Dependent Object Type (DOT) calculus was designed to put Scala on a sound basis, but while DOT relies on structural subtyping, Scala is a fundamentally class-based language. This impedance mismatch means that a proof of DOT soundness by itself is ...

EPFL2023

Type-preserving compilation of (most of) FGJ into DOT

Guillaume André Fradji Martres

2022

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

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

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 ...

New York2022

FTLD-TDP assemblies seed neoaggregates with subtype-specific features via a prion-like cascade

Henning Paul-Julius Stahlberg, Amanda Jennifer Lewis, Marta Di Fabrizio, Julien Weber

Morphologically distinct TDP-43 aggregates occur in clinically different FTLD-TDP subtypes, yet the mechanism of their emergence and contribution to clinical heterogeneity are poorly understood. Several lines of evidence suggest that pathological TDP-43 fo ...

WILEY2021

Celsius: A Model for Safe Initialization of Objects

Martin Odersky, Fengyun Liu, Paolo Giosuè Giarrusso

Accessing uninitialized data during object initialization is a common and subtle programming error. This error is either not prevented by mainstream languages, like in Java, C++, Scala, or it is prevented by greatly restricting initialization patterns, lik ...

2020

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

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

Type Soundness for Dependent Object Types (DOT)

Tiark Rompf, Nada Amin

Scala's type system unifies aspects of ML modules, object-oriented, and functional programming. The Dependent Object Types (DOT) family of calculi has been proposed as a new theoretic foundation for Scala and similar expressive languages. Unfortunately, ty ...

Assoc Computing Machinery2016

Type Soundness for Dependent Object Types’

Tiark Rompf, Nada Amin

Scala’s type system unifies aspects of ML modules, object-oriented, and functional programming. The Dependent Object Types (DOT) family of calculi has been proposed as a new theoretic foundation for Scala and similar expressive languages. Unfortunately, ty ...

2016

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