How Ur/Web records work and what it might mean for Haskell April 20, 2012
Ur is a programming language, which among other things, has a rather interesting record system. Record systems are a topic of rather intense debate in the Haskell community, and I noticed that someone had remarked “[Ur/Web has a http://www.impredicative.com/ur/tutorial/tlc.html very advanced records system]. If someone could look at the UR implementation paper and attempt to distill a records explanation to a Haskell point of view that would be very helpful!” This post attempts to perform that distillation, based off my experiences interacting with the Ur record system and one of its primary reasons for existence: metaprogramming. (Minor nomenclature note: Ur is the base language, while Ur/Web is a specialization of the base language for web programming, that also happens to actually have a compiler. For the sake of technical precision, I will refer to the language as Ur throughout this article.)
