I consider this to be the better alternative. My workflow often starts with stating the domains of variables in a mathematical sense. At least in my head, at least to the point that I can distinguish logics / counting from “number crunching”.
This reminds me of a half-page long footnote from the first chapter of the Wizard Book:
There was / is also a discussion on what a number in Julia is / should be: Interface for number. I’m unsure if the proposed interface / testset exists now. I think my intention was focused practical scalars used for number crunching: T <: Real. Hopefully more advanced stuff like quaternions can be parameterized with underlying T.
Different number formats come to my mind only when I have to think of some sort of scaling or restrictions: How long will these calculations take with large inputs? Will it work on a microcontroller, accelerator, etc.? Is inexactness a problem, what can go wrong? Such things…