You might not have seen this pattern before, but annotating values with units as types is a legitimate approach. There’s a whole chapter about it in the book So

You might not have seen this pattern before, but annotating values with units as types is a legitimate approach. There’s a whole chapter about it in the book Software Design for Flexibility by Gerald Sussmann, the author of Structure and Interpretation of Computer Programs, which is linked on here pretty often. It has to be done in the right way, though, in a language that’s expressive enough to support it.