I don't think there's an alternative to optional static type checking at this point. Like you say, there's a bunch of untyped code out there. I'd actually hate

I don't think there's an alternative to optional static type checking at this point. Like you say, there's a bunch of untyped code out there. I'd actually hate to see a JS/TS divide in PHP. The typing needs to really be a superset of existing PHP and backwards compatible. Such a typechecker should cover at least the following: 1. Point it to a codebase and spit out a bunch of errors/warnings; and 2. Run it at runtime where type checks are logged or a strict mode where they're fatal.