The turnstile language
|#lang turnstile||package: turnstile|
Turnstile aims to help Racket programmers create typed languages. It does so with extensions of Racket’s macro-definition forms that facilitate implementation of type rules alongside normal macro code. As a result, the macros implementing a new language directly type check the program during expansion, obviating the need to create and call out to a separate type checker. Thus, a complete typed language implementation remains a series of macro definitions that may be imported and exported in the standard way that Racket programmers are accustomed to.