Type Systems as Macros.
Stephen Chang, Alex Knauth, Ben Greenman.
44th ACM SIGPLAN Symposium on Principles of Programming Languages (POPL), Paris, France, January 18-20, 2017 (to appear).

pdf  | code repo  | artifact instructions, VirtualBox image (2.1GB) ]

We present Turnstile, a metalanguage for creating typed embedded languages. To implement the type system, programmers write type checking rules resembling traditional judgment syntax. To implement the semantics, they incorporate elaborations into these rules. Turnstile critically depends on the idea of linguistic reuse. It exploits a macro system in a novel way to simultaneously type check and rewrite a surface program into a target language. Reusing a macro system also yields modular implementations whose rules may be mixed and matched to create other languages. Combined with typical compiler and runtime reuse, Turnstile produces performant typed embedded languages with little effort.

Links to runnable versions of examples from the paper:

Installing Turnstile

You must have Racket installed to use Turnstile. Turnstile documentation

Artifact Instructions

VM Image (recommended)

Manual Installation (only if VM is malfunctioning)