Publications de Martin Odersky

Static Typing Meets Adaptive Optimization: A Unified Approach to Recursive Queries

Martin Odersky, Anastasia Ailamaki, Anna Patricia Herlihy

Writing correct and efficient recursive SQL queries is exceptionally challenging because recursive queries risk returning incorrect results, throwing runtime exceptions, or never terminating. Failures in recursive query execution fall into two categories: ...

ACM2025

Degrees of Separation: A Flexible Type System for Safe Concurrency

Martin Odersky, Aleksander Slawomir Boruch-Gruszecki, Yichen Xu

Data races have long been a notorious problem in concurrent programming. They are subtle to detect, and lead to non-deterministic behaviours. There has been a lot of interest in type systems that statically guarantee data race freedom. Significant progress ...

2024

Adaptive Recursive Query Optimization

Martin Odersky, Anastasia Ailamaki, Guillaume André Fradji Martres, Anna Patricia Herlihy

Performance-critical industrial applications, including large-scale program, network, and distributed system analyses, are increasingly reliant on recursive queries for data analysis. Yet traditional relational algebra-based query optimization techniques d ...

IEEE2024

Stack-Copying Delimited Continuations for Scala Native

Martin Odersky

Scala, an industrial-strength functional and object-oriented programming language, is in need for an ergonomic approach to asynchronous programming. Project Loom provides direct-style concurrency to Scala on the JVM, which leaves its low-footprint high-per ...

Association for Computing Machinery, Inc2024

A Formal Foundation of Reach Capabilities

Martin Odersky, Yichen Xu

Though being seemingly orthogonal, the scoping restrictions enforced by capture checking and mutable variables give rise to surprising challenges when they interact. To obtain a system that is both sound and expressive, the Scala capture checker introduced ...

Association for Computing Machinery, Inc2024

Capturing Types

Martin Odersky, Ondrej Lhoták, Aleksander Slawomir Boruch-Gruszecki

Type systems usually characterize the shape of values but not their free variables. However, many desirable safety properties could be guaranteed if one knew the free variables captured by values. We describe CC

Assoc Computing Machinery2023

Type-Level Programming with Match Types

Martin Odersky, Olivier Eric Paul Blanvillain

Type-level programming is becoming more and more popular in the realm of functional programming. However, the combination of type-level programming and subtyping remains largely unexplored in practical programming languages. This paper presents match types ...

ASSOC COMPUTING MACHINERY2022

Safer exceptions for Scala

Martin Odersky, Ondrej Lhoták, Aleksander Slawomir Boruch-Gruszecki, Jonathan Immanuel Brachthäuser

2021

Representing Monads with Capabilities

Martin Odersky, Aleksander Slawomir Boruch-Gruszecki, Jonathan Immanuel Brachthäuser

Programming with monads can be advantageous even in imperative languages with builtin support for side effects. However, in these languages composing monadic programs is different from composing side effecting imperative programs. This does not need to be ...

2021

Virtual ADTs for Portable Metaprogramming

Martin Odersky, Nicolas Alexander Stucki

Scala 3 provides a metaprogramming interface that represents the abstract syntax tree definitions using algebraic data types. To allow the compiler to freely evolve without breaking the metaprogramming interface, we present virtual algebraic data types (or ...

ASSOC COMPUTING MACHINERY2021

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

A Type-and-Effect System for Object Initialization

Martin Odersky, Fengyun Liu, Ondrej Lhoták, Paolo Giosuè Giarrusso

Every newly created object goes through several initialization states: starting from a state where all fields are uninitialized until all of them are assigned. Any operation on the object during its initialization process, which usually happens in the cons ...

ASSOC COMPUTING MACHINERY2020

Stoic: Towards Disciplined Capabilities

Martin Odersky, Sandro Stucki, Nada Amin, Fengyun Liu, Paolo Giosuè Giarrusso

Capabilities are widely used in the design of software systems to ensure security. A system of capabilities can become a mess in the presence of objects and functions: objects may leak capabilities and functions may capture capabilities. They make reasonin ...

2020

Semantics-preserving inlining for metaprogramming

Martin Odersky, Nicolas Alexander Stucki, Sébastien Jean R Doeraene

Inlining is used in many different ways in programming languages: some languages use it as a compiler-directive solely for optimization, some use it as a metaprogramming feature, and others lay their design in-between. This paper presents inlining through ...

2020

Safe Initialization of Objects

Martin Odersky, Fengyun Liu, Ondrej Lhoták, Paolo Giosuè Giarrusso

Every newly created object goes through several initialization states: starting from a state where all fields are uninitialized until all of them are assigned. Any operation on the object during its initialization process, which usually happens in the cons ...

2020

Interflow: interprocedural flow-sensitive type inference and method duplication

Martin Odersky, Denys Shabalin

Scala heavily relies on a number of object-oriented abstractions to support its feature-rich collections library. There are known techniques that optimize those abstractions away in just-in-time (JIT) compilers, but applying them in the ahead-of-time (AOT) ...

2018

A Practical Unification of Multi-stage Programming and Macros

Martin Odersky, Nicolas Alexander Stucki

Program generation is indispensable. We propose a novel unification of two existing metaprogramming techniques: multi-stage programming and hygienic generative macros. The former supports runtime code generation and execution in a type-safe manner while th ...

2018

Initialization patterns in Dotty

Martin Odersky, Fengyun Liu

Safe object initialization is important to avoid a category of runtime errors in programming languages. In this paper, we provide a case study of the initialization patterns on the Dotty compiler. In particular, we find that calling dynamic-dispatching met ...

2018

Truly abstract interfaces for algebraic data types: the extractor typing problem

Martin Odersky, Nicolas Alexander Stucki, Paolo Giosuè Giarrusso

Pattern matching enables inspecting algebraic data types, but typically prevents hiding the implementation of the matched algebraic data type. In Scala, instead, extractors also allow pattern matching on non-algebraic data types and invoking methods on the ...

2018

Miniphases: Compilation using Modular and Efficient Tree Transformations

Martin Odersky, Dmytro Petrashko, Ondrej Lhoták

Production compilers commonly perform dozens of transformations on an intermediate representation. Running those transformations in separate passes harms performance. One approach to recover performance is to combine transformations by hand in order to red ...

Assoc Computing Machinery2017