Stephanie Weirich



December 05, 2017 at 12:00pm (lunch talk)
CSE 305


What has dependent type theory done for Haskell? Over the past ten years, the Glasgow Haskell compiler (GHC) has adopted many type system features inspired by dependent type theory. In this talk, I will discuss the influence of dependent types on the design of GHC and on the practice of Haskell programmers. In particular, I will walk through an extended example and use it to analyze what it means to program with with dependent types in Haskell. Throughout, I will will discuss what we have learned from this experiment in language design: what works now, what doesn’t work yet, and what surprised us along the way.


Stephanie Weirich is a Professor of Computer and Information Science at the University of Pennsylvania. She has published broadly in the areas of functional programming, type systems, machine-assisted theorem proving and dependent types. During the past ten years, she and her students have made significant contributions to the design of the Glasgow Haskell Compiler. Dr. Weirich has served as the program chair of the ICFP 2010 and the 2009 Haskell Symposium and is also an editor of the Journal of Functional Programming. Her recent awards include the 2016 Most Influential ICFP Paper award (for 2006) for the paper “Simple unification-based type inference for GADTs” and the 2016 ACM SIGPLAN Robin Milner Young Researcher Award.