// the find
munificent/vigil
Vigil, the eternal morally vigilant programming language
Vigil is a joke language from a 2013 game jam that enforces contracts by deleting the offending function from your source file when a precondition or postcondition fails. It's Python with a preprocessing layer that rewrites `implore`/`swear` statements into assertion checks and a runtime that mutates disk on failure. It's a bit and a good one.
The central joke lands: the escalating logic in the FAQ ('those callers appear to be corrupted as well') is genuinely funny and makes a real point about how contracts should work. It's by Bob Nystrom (author of Crafting Interpreters), so the implementation is clean for what it is. The concept of 'survival of the fittest code' is a memorable way to think about contract enforcement.
It's a 2013 jam entry with three example files and no real development since — this is not something you run on actual code. The Python-based implementation is minimal enough that edge cases in the source rewriting will break immediately on anything non-trivial. Stars are high purely because of Nystrom's name recognition and the joke value; there's no ecosystem, no language spec, and no path to making it useful.