Lambda the Ultimate

The idea of mining code repositories to tease out language design issues have been discussed before on LtU. In this paper, J. Garrett Morris looks at the usage of overlapping instances in the Haskell code repository site hackage on deciding whether to include the feature in a new language.

Using Hackage to Inform Language Design
Abstract

Hackage, an online repository of Haskell applications and libraries, provides a hub for programmers to both release code to and use code from the larger Haskell community. We suggest that Hackage can also serve as a valuable resource for language designers: by providing a large collection of code written by different program- mers and in different styles, it allows language designers to see not just how features could be used theoretically, but how they are (and are not) used in practice.We were able to make such a use of Hackage during the design of the class system for a new Haskell-like programming language. In this paper, we sketch our language design problem, and how we used Hackage to help answer it. We describe our methodology in some detail, including both ways that it was and was not effective, and summarize our results.