Today, 2023-10-04, at 1000 UTC (3:00 am PDT, 6:00 am EDT, 11:00 am BST, 12:00 CEST, 13:00 EEST, 3:30 pm IST, 19:00 JST, 9:00 pm AEDT, …) we are streaming the twelfth episode of the Haskell Unfolder live on YouTube.
We will look at the concept of parametricity, also known as “theorems for free.”The idea of parametricity is that you can make non-trivial statements about polymorphic functions simply by looking at their types, but without knowing anything about their implementation. We will focus on the intuition, not the theory, and explain how parametricity can generally help with reasoning about programs.
About the Haskell Unfolder
The Haskell Unfolder is a YouTube series about all things Haskell hosted by Edsko de Vries and Andres Löh, with episodes appearing approximately every two weeks. All episodes are live-streamed, and we try to respond to audience questions. All episodes are also available as recordings afterwards.
We have a GitHub repository with code samples from the episodes.