> As for why we do so much at runtime, my assertion is we check at runtime that which is determined at runtime. When getting data from outside the static progra

> As for why we do so much at runtime, my assertion is we check at runtime that which is determined at runtime. When getting data from outside the static program, there is little help the static type system can offer. So, deep in your system, get things out of strings and primitives as soon as you can. Don't pass a string username, pass a username. This gets you essentially what you want, but flags where the invalid value could have come from, as well as where it could have been used. And lets you add on other validations. AuthenticatedUsername and UnauthenticatedUsername, for example. See, but that's exactly what I'm saying. Get out of primitives ASAP. I just want our languages to allow us to do that with minimal ceremony and minimal performance cost. Most languages fail on at least one of those. As a result, most developers don't do it, and I'm stuck interacting with their code.