I do most of my research in Racket (Herbie, Cassius). I work in programming languages, so most of my code manipulates programs as data. Racket is a wonderful language for this thanks to its extensive support for S-expression program representations: pattern matching, quasi-quoting, and a bevy of list manipulation functions all help manipulate programs. However, writing down type signatures or contracts for S-expression based data structures is a pain. This post is about a helpful macro, defin...
