It turned out that Grapefruit 0.1.0.6 could not be built with GHC 7.10.3, apparently because of a bug in the compiler. Now a new version of Grapefruit, version 0.1.0.7, is out, which works around this problem.
One of the most important ingredients of Haskell is its type system. Standard Haskell already provides a lot of useful mechanisms for having things checked at compile time, and the language extensions provided by the Glasgow Haskell Compiler (GHC) improve heavily on this.
In this article, I will present several of Haskell’s type system features. Some of them belong to the standard, others are only available as extensions. This is a write-up of a talk I gave on 31 January 2013 during the Theory Lunch of the Institute of Cybernetics. This talk provided the basics for another Theory Lunch talk, which was about the Constraint kind. Continue reading →