This program is tentative and subject to change.

Fri 25 Oct 2024 14:50 - 15:10 at IBR West - Novel Programming Concepts and Paradigms Chair(s): Tobias Wrigstad

Functional programming languages typically support expressive pattern-matching syntax that allows programmers to write concise, expressive, and type-safe code for manipulating algebraic data types. Many features have been proposed to enhance the expressiveness of pattern-matching syntax, such as pattern bindings, pattern alternatives (a.k.a. disjunction), pattern conjunction, view patterns, pattern guards, pattern synonyms, active patterns, ‘if-let’ patterns, multi-way if-expressions, etc. In this paper, we propose a new framework for expressing pattern-matching code in a way that is both more expressive and (we argue) more readable than previous alternatives. Our syntax subsumes many proposed pattern matching extensions by enabling the expression of parallel and nested matches interleaved with computations and intermediate bindings. This is achieved through a form of nested multi-way if-expressions with a condition-splitting mechanism to factor common conditional prefixes as well as a binding technique we call conditional pattern flowing. We motivate this new syntax with many examples in the setting of MLscript, a new ML-family programming language. We describe a straightforward desugaring pass from our rich source syntax into a minimal core syntax that only supports flat pattern matching (i.e., without nested patterns) along with an intuitive small-step semantics for the core syntax. We also formalize a translation from the core syntax into a normalized syntax without backtracking that is more amenable to type checking, coverage checking, and compilation. We then formally prove that our translation preserves the semantics of the core syntax. We view this work as a step towards rethinking pattern-matching to make it more expressive and readable. Our syntax could easily be integrated, in part or in whole, into existing as well as future programming language designs.

This program is tentative and subject to change.

Fri 25 Oct

Displayed time zone: Pacific Time (US & Canada) change

13:50 - 15:30
Novel Programming Concepts and ParadigmsOOPSLA 2024 at IBR West
Chair(s): Tobias Wrigstad Uppsala University
13:50
20m
Talk
A Case for First-Class Environments
OOPSLA 2024
Jinhao Tan University of Hong Kong, Bruno C. d. S. Oliveira University of Hong Kong
DOI
14:10
20m
Talk
Deriving Dependently-Typed OOP from First Principles
OOPSLA 2024
David Binder University of Tübingen, Ingo Skupin University of Tübingen, Tim Süberkrüb Aleph Alpha, Klaus Ostermann University of Tübingen
DOI
14:30
20m
Talk
Multiverse Notebook: Shifting Data Scientists to Time Travelers
OOPSLA 2024
Shigeyuki Sato The University of Electro-Communications, Tomoki Nakamaru The University of Tokyo
DOI
14:50
20m
Talk
The Ultimate Conditional SyntaxOOPSLA 2024 Distinguished Paper Award
OOPSLA 2024
Luyu Cheng Hong Kong University of Science and Technology, Lionel Parreaux HKUST (The Hong Kong University of Science and Technology)
DOI
15:10
20m
Talk
Unifying Static and Dynamic Intermediate Languages for Accelerator Generators
OOPSLA 2024
Caleb Kim Cornell University, Pai Li Cornell University, USA, Anshuman Mohan Cornell University, Andrew Butt Cornell University, Adrian Sampson Cornell University, Rachit Nigam Massachusetts Institute of Technology
DOI