this sounds a little silly but it think Nim's converter routines + distinct
types can allow for something really cool: in my codebase there is a part which
I wrote with one-indexed convention because that's the norm in the mathematical
community and it's easier to work with (and that code doesn't actually have
anything to do with arrays but it still has the concept of indices). but a lot
of the rest of the code is 0-indexed because it actually deals with arrays.
defining a distinct types for indices here with converter routines that properly
translate between them is really useful and allows you to avoid one-off errors
in a type checked way