MuniHac 2020: Richard Eisenberg - Partial Type Constructors

Title: Partial Type Constructors
Speaker: Richard Eisenberg

When we describe the type Set a, we say that this type makes sense for any a. But this is a small lie: it really only makes sense for types a that have an ordering – that is, types for which Ord a holds. This small lie has far-reaching consequences. It means that we cannot write a Functor instance for Set, it means we might accidentally write uncallable functions that take a Set, and it means we must repetitively write Ord a ... constraints on every function working with Sets.

This talk will explore the possibility of explicitly partial type constructors, where we can declare loudly that types like Set work only with some type arguments, but not others. The design proposed improves error messages, simplifies type signatures, and allows instances like Functor over Sets.

MuniHac 2020, September 11 / https://munihac.de/
TNG Technology Consulting GmbH / https://www.tngtech.com

Видео MuniHac 2020: Richard Eisenberg - Partial Type Constructors канала TNG Technology Consulting GmbH